chore: imports/types

Add summarization config and package-level summarize handler contracts Register summarize handlers across server controller paths Port cursor dual-read/dual-write summary support and UI status handling Selectively merge cursor branch files for BaseClient summary content block detection (last-summary-wins), dual-write persistence, summary block unit tests, and on_summarize_status SSE event handling with started/completed/failed branches. Co-authored-by: Cursor <cursoragent@cursor.com> refactor: type safety feat: add localization for summarization status messages refactor: optimize summary block detection in BaseClient Updated the logic for identifying existing summary content blocks to use a reverse loop for improved efficiency. Added a new test case to ensure the last summary content block is updated correctly when multiple summary blocks exist. chore: add runName to chainOptions in AgentClient refactor: streamline summarization configuration and handler integration Removed the deprecated summarizeNotConfigured function and replaced it with a more flexible createSummarizeFn. Updated the summarization handler setup across various controllers to utilize the new function, enhancing error handling and configuration resolution. Improved overall code clarity and maintainability by consolidating summarization logic. feat(summarization): add staged chunk-and-merge fallback feat(usage): track summarization usage separately from messages feat(summarization): resolve prompt from config in runtime fix(endpoints): use @librechat/api provider config loader refactor(agents): import getProviderConfig from @librechat/api chore: code order feat(app-config): auto-enable summarization when configured feat: summarization config refactor(summarization): streamline persist summary handling and enhance configuration validation Removed the deprecated createDeferredPersistSummary function and integrated a new createPersistSummary function for MongoDB persistence. Updated summarization handlers across various controllers to utilize the new persistence method. Enhanced validation for summarization configuration to ensure provider, model, and prompt are properly set, improving error handling and overall robustness. refactor(summarization): update event handling and remove legacy summarize handlers Replaced the deprecated summarization handlers with new event-driven handlers for summarization start and completion across multiple controllers. This change enhances the clarity of the summarization process and improves the integration of summarization events in the application. Additionally, removed unused summarization functions and streamlined the configuration loading process. refactor(summarization): standardize event names in handlers Updated event names in the summarization handlers to use constants from GraphEvents for consistency and clarity. This change improves maintainability and reduces the risk of errors related to string literals in event handling. feat(summarization): enhance usage tracking for summarization events Added logic to track summarization usage in multiple controllers by checking the current node type. If the node indicates a summarization task, the usage type is set accordingly. This change improves the granularity of usage data collected during summarization processes. feat(summarization): integrate SummarizationConfig into AppSummarizationConfig type Enhanced the AppSummarizationConfig type by extending it with the SummarizationConfig type from librechat-data-provider. This change improves type safety and consistency in the summarization configuration structure. test: add end-to-end tests for summarization functionality Introduced a comprehensive suite of end-to-end tests for the summarization feature, covering the full LibreChat pipeline from message creation to summarization. This includes a new setup file for environment configuration and a Jest configuration specifically for E2E tests. The tests utilize real API keys and ensure proper integration with the summarization process, enhancing overall test coverage and reliability. refactor(summarization): include initial summary in formatAgentMessages output Updated the formatAgentMessages function to return an initial summary alongside messages and index token count map. This change is reflected in multiple controllers and the corresponding tests, enhancing the summarization process by providing additional context for each agent's response. refactor: move hydrateMissingIndexTokenCounts to tokenMap utility Extracted the hydrateMissingIndexTokenCounts function from the AgentClient and related tests into a new tokenMap utility file. This change improves code organization and reusability, allowing for better management of token counting logic across the application. refactor(summarization): standardize step event handling and improve summary rendering Refactored the step event handling in the useStepHandler and related components to utilize constants for event names, enhancing consistency and maintainability. Additionally, improved the rendering logic in the Summary component to conditionally display the summary text based on its availability, providing a better user experience during the summarization process. feat(summarization): introduce baseContextTokens and reserveTokensRatio for improved context management Added baseContextTokens to the InitializedAgent type to calculate the context budget based on agentMaxContextNum and maxOutputTokensNum. Implemented reserveTokensRatio in the createRun function to allow configurable context token management. Updated related tests to validate these changes and ensure proper functionality. feat(summarization): add minReserveTokens, context pruning, and overflow recovery configurations Introduced new configuration options for summarization, including minReserveTokens, context pruning settings, and overflow recovery parameters. Updated the createRun function to accommodate these new options and added a comprehensive test suite to validate their functionality and integration within the summarization process. feat(summarization): add updatePrompt and reserveTokensRatio to summarization configuration Introduced an updatePrompt field for updating existing summaries with new messages, enhancing the flexibility of the summarization process. Additionally, added reserveTokensRatio to the configuration schema, allowing for improved management of token allocation during summarization. Updated related tests to validate these new features. feat(logging): add on_agent_log event handler for structured logging Implemented an on_agent_log event handler in both the agents' callbacks and responses to facilitate structured logging of agent activities. This enhancement allows for better tracking and debugging of agent interactions by logging messages with associated metadata. Updated the summarization process to ensure proper handling of log events. fix: remove duplicate IBalanceUpdate interface declaration perf(usage): single-pass partition of collectedUsage Replace two Array.filter() passes with a single for-of loop that partitions message vs. summarization usages in one iteration. fix(BaseClient): shallow-copy message content before mutating and preserve string content Avoid mutating the original message.content array in-place when appending a summary block. Also convert string content to a text content part instead of silently discarding it. fix(ui): fix Part.tsx indentation and useStepHandler summarize-complete handling - Fix SUMMARY else-if branch indentation in Part.tsx to match chain level - Guard ON_SUMMARIZE_COMPLETE with didFinalize flag to avoid unnecessary re-renders when no summarizing parts exist - Protect against undefined completeData.summary instead of unsafe spread fix(agents): use strict enabled check for summarization handlers Change summarizationConfig?.enabled !== false to === true so handlers are not registered when summarizationConfig is undefined. chore: fix initializeClient JSDoc and move DEFAULT_RESERVE_RATIO to module scope refactor(Summary): align collapse/expand behavior with Reasoning component - Single render path instead of separate streaming vs completed branches - Use useMessageContext for isSubmitting/isLatestMessage awareness so the "Summarizing..." label only shows during active streaming - Default to collapsed (matching Reasoning), user toggles to expand - Add proper aria attributes (aria-hidden, role, aria-controls, contentId) - Hide copy button while actively streaming feat(summarization): default to self-summarize using agent's own provider/model When no summarization config is provided (neither in librechat.yaml nor on the agent), automatically enable summarization using the agent's own provider and model. The agents package already provides default prompts, so no prompt configuration is needed. Also removes the dead resolveSummarizationLLMConfig in summarize.ts (and its spec) — run.ts buildAgentContext is the single source of truth for summarization config resolution. Removes the duplicate RuntimeSummarizationConfig local type in favor of the canonical SummarizationConfig from data-provider. chore: schema and type cleanup for summarization - Add trigger field to summarizationAgentOverrideSchema so per-agent trigger overrides in librechat.yaml are not silently stripped by Zod - Remove unused SummarizationStatus type from runs.ts - Make AppSummarizationConfig.enabled non-optional to reflect the invariant that loadSummarizationConfig always sets it refactor(responses): extract duplicated on_agent_log handler refactor(run): use agents package types for summarization config Import SummarizationConfig, ContextPruningConfig, and OverflowRecoveryConfig from @librechat/agents and use them to type-check the translation layer in buildAgentContext. This ensures the config object passed to the agent graph matches what it expects. - Use `satisfies AgentSummarizationConfig` on the config object - Cast contextPruningConfig and overflowRecoveryConfig to agents types - Properly narrow trigger fields from DeepPartial to required shape feat(config): add maxToolResultChars to base endpoint schema Add maxToolResultChars to baseEndpointSchema so it can be configured on any endpoint in librechat.yaml. Resolved during agent initialization using getProviderConfig's endpoint resolution: custom endpoint config takes precedence, then the provider-specific endpoint config, then the shared `all` config. Passed through to the agents package ToolNode, which uses it to cap tool result length before it enters the context window. When not configured, the agents package computes a sensible default from maxContextTokens. fix(summarization): forward agent model_parameters in self-summarize default When no explicit summarization config exists, the self-summarize default now forwards the agent's model_parameters as the summarization parameters. This ensures provider-specific settings (e.g. Bedrock region, credentials, endpoint host) are available when the agents package constructs the summarization LLM. fix(agents): register summarization handlers by default Change the enabled gate from === true to !== false so handlers register when no explicit summarization config exists. This aligns with the self-summarize default where summarization is always on unless explicitly disabled via enabled: false. refactor(summarization): let agents package inherit clientOptions for self-summarize Remove model_parameters forwarding from the self-summarize default. The agents package now reuses the agent's own clientOptions when the summarization provider matches the agent's provider, inheriting all provider-specific settings (region, credentials, proxy, etc.) automatically. refactor(summarization): use MessageContentComplex[] for summary content Unify summary content to always use MessageContentComplex[] arrays, matching the pattern used by on_message_delta. No more string | array unions — content is always an array of typed blocks ({ type: 'text', text: '...' } for text, { type: 'reasoning_content', ... } for reasoning). Agents package: - SummaryContentBlock.content: MessageContentComplex[] (was string) - tokenCount now optional (not sent on deltas) - Removed reasoning field — reasoning is now a content block type - streamAndCollect normalizes all chunks to content block arrays - Delta events pass content blocks directly LibreChat: - SummaryContentPart.content: Agents.MessageContentComplex[] - Updated Part.tsx, Summary.tsx, useStepHandler.ts, BaseClient.js - Summary.tsx derives display text from content blocks via useMemo - Aggregator uses simple array spread refactor(summarization): enhance summary handling and text extraction - Updated BaseClient.js to improve summary text extraction, accommodating both legacy and new content formats. - Modified summarization logic to ensure consistent handling of summary content across different message formats. - Adjusted test cases in summarization.e2e.spec.js to utilize the new summary text extraction method. - Refined SSE useStepHandler to initialize summary content as an array. - Updated configuration schema by removing unused minReserveTokens field. - Cleaned up SummaryContentPart type by removing rangeHash property. These changes streamline the summarization process and ensure compatibility with various content structures. refactor(summarization): streamline usage tracking and logging - Removed direct checks for summarization nodes in ModelEndHandler and replaced them with a dedicated markSummarizationUsage function for better readability and maintainability. - Updated OpenAIChatCompletionController and responses handlers to utilize the new markSummarizationUsage function for setting usage types. - Enhanced logging functionality by ensuring the logger correctly handles different log levels. - Introduced a new useCopyToClipboard hook in the Summary component to encapsulate clipboard copy logic, improving code reusability and clarity. These changes improve the overall structure and efficiency of the summarization handling and logging processes. refactor(summarization): update summary content block documentation - Removed outdated comment regarding the last summary content block in BaseClient.js. - Added a new comment to clarify the purpose of the findSummaryContentBlock method, ensuring consistency in documentation. These changes enhance code clarity and maintainability by providing accurate descriptions of the summarization logic. refactor(summarization): update summary content structure in tests - Modified the summarization content structure in e2e tests to use an array format for text, aligning with recent changes in summary handling. - Updated test descriptions to clarify the behavior of context token calculations, ensuring consistency and clarity in the tests. These changes enhance the accuracy and maintainability of the summarization tests by reflecting the updated content structure. refactor(summarization): remove legacy E2E test setup and configuration - Deleted the e2e-setup.js and jest.e2e.config.js files, which contained legacy configurations for E2E tests using real API keys. - Introduced a new summarization.e2e.ts file that implements comprehensive E2E backend integration tests for the summarization process, utilizing real AI providers and tracking summaries throughout the run. These changes streamline the testing framework by consolidating E2E tests into a single, more robust file while removing outdated configurations. refactor(summarization): enhance E2E tests and error handling - Added a cleanup step to force exit after all tests to manage Redis connections. - Updated the summarization model to 'claude-haiku-4-5-20251001' for consistency across tests. - Improved error handling in the processStream function to capture and return processing errors. - Enhanced logging for cross-run tests and tight context scenarios to provide better insights into test execution. These changes improve the reliability and clarity of the E2E tests for the summarization process. refactor(summarization): enhance test coverage for maxContextTokens behavior - Updated run-summarization.test.ts to include a new test case ensuring that maxContextTokens does not exceed user-defined limits, even when calculated ratios suggest otherwise. - Modified summarization.e2e.ts to replace legacy UsageMetadata type with a more appropriate type for collectedUsage, improving type safety and clarity in the test setup. These changes improve the robustness of the summarization tests by validating context token constraints and refining type definitions. feat(summarization): add comprehensive E2E tests for summarization process - Introduced a new summarization.e2e.test.ts file that implements extensive end-to-end integration tests for the summarization pipeline, covering the full flow from LibreChat to agents. - The tests utilize real AI providers and include functionality to track summaries during and between runs. - Added necessary cleanup steps to manage Redis connections post-tests and ensure proper exit. These changes enhance the testing framework by providing robust coverage for the summarization process, ensuring reliability and performance under real-world conditions. fix(service): import logger from winston configuration - Removed the import statement for logger from '@librechat/data-schemas' and replaced it with an import from '~/config/winston'. - This change ensures that the logger is correctly sourced from the updated configuration, improving consistency in logging practices across the application. refactor(summary): simplify Summary component and enhance token display - Removed the unused `meta` prop from the `SummaryButton` component to streamline its interface. - Updated the token display logic to use a localized string for better internationalization support. - Adjusted the rendering of the `meta` information to improve its visibility within the `Summary` component. These changes enhance the clarity and usability of the Summary component while ensuring better localization practices. feat(summarization): add maxInputTokens configuration for summarization - Introduced a new `maxInputTokens` property in the summarization configuration schema to control the amount of conversation context sent to the summarizer, with a default value of 10000. - Updated the `createRun` function to utilize the new `maxInputTokens` setting, allowing for more flexible summarization based on agent context. These changes enhance the summarization capabilities by providing better control over input token limits, improving the overall summarization process. refactor(summarization): simplify maxInputTokens logic in createRun function - Updated the logic for the `maxInputTokens` property in the `createRun` function to directly use the agent's base context tokens when the resolved summarization configuration does not specify a value. - This change streamlines the configuration process and enhances clarity in how input token limits are determined for summarization. These modifications improve the maintainability of the summarization configuration by reducing complexity in the token calculation logic. feat(summary): enhance Summary component to display meta information - Updated the SummaryContent component to accept an optional `meta` prop, allowing for additional contextual information to be displayed above the main content. - Adjusted the rendering logic in the Summary component to utilize the new `meta` prop, improving the visibility of supplementary details. These changes enhance the user experience by providing more context within the Summary component, making it clearer and more informative. refactor(summarization): standardize reserveRatio configuration in summarization logic - Replaced instances of `reserveTokensRatio` with `reserveRatio` in the `createRun` function and related tests to unify the terminology across the codebase. - Updated the summarization configuration schema to reflect this change, ensuring consistency in how the reserve ratio is defined and utilized. - Removed the per-agent override logic for summarization configuration, simplifying the overall structure and enhancing clarity. These modifications improve the maintainability and readability of the summarization logic by standardizing the configuration parameters.
2026-07-11 00:33:40 +00:00 · 2026-02-17 18:23:44 -05:00 · 2026-02-17 18:23:44 -05:00 · 10bcf4702f
commit 10bcf4702f
parent d4c02d6ba6
35 changed files with 2483 additions and 256 deletions
--- a/api/app/clients/BaseClient.js
+++ b/api/app/clients/BaseClient.js
@ -356,6 +356,32 @@ class BaseClient {

        update.summary = tokenCountMap.summaryMessage.content;
        update.summaryTokenCount = tokenCountMap.summaryMessage.tokenCount;
+
+        const summaryContentBlock = {
+          type: ContentTypes.SUMMARY,
+          content: [{ type: ContentTypes.TEXT, text: tokenCountMap.summaryMessage.content }],
+          tokenCount: tokenCountMap.summaryMessage.tokenCount,
+          createdAt: new Date().toISOString(),
+        };
+        let existingContent = [];
+        if (Array.isArray(message.content)) {
+          existingContent = [...message.content];
+        } else if (message.content) {
+          existingContent = [{ type: ContentTypes.TEXT, text: message.content }];
+        }
+        let existingSummaryIndex = -1;
+        for (let index = existingContent.length - 1; index >= 0; index--) {
+          if (existingContent[index]?.type === ContentTypes.SUMMARY) {
+            existingSummaryIndex = index;
+            break;
+          }
+        }
+        if (existingSummaryIndex >= 0) {
+          existingContent[existingSummaryIndex] = summaryContentBlock;
+        } else {
+          existingContent.push(summaryContentBlock);
+        }
+        update.content = existingContent;
      }

      if (message.tokenCount && !update.summaryTokenCount) {
@ -934,10 +960,24 @@ class BaseClient {
      return _messages;
    }

-    // Find the latest message with a 'summary' property
    for (let i = _messages.length - 1; i >= 0; i--) {
-      if (_messages[i]?.summary) {
-        this.previous_summary = _messages[i];
+      const msg = _messages[i];
+      if (!msg) {
+        continue;
+      }
+
+      const summaryBlock = BaseClient.findSummaryContentBlock(msg);
+      if (summaryBlock) {
+        this.previous_summary = {
+          ...msg,
+          summary: BaseClient.getSummaryText(summaryBlock),
+          summaryTokenCount: summaryBlock.tokenCount,
+        };
+        break;
+      }
+
+      if (msg.summary) {
+        this.previous_summary = msg;
        break;
      }
    }
@ -1041,6 +1081,32 @@ class BaseClient {
    await db.updateMessage(this.options?.req?.user?.id, message);
  }

+  /** Extracts text from a summary block (handles both legacy `text` field and new `content` array format). */
+  static getSummaryText(summaryBlock) {
+    if (Array.isArray(summaryBlock.content)) {
+      return summaryBlock.content.map((b) => b.text ?? '').join('');
+    }
+    if (typeof summaryBlock.content === 'string') {
+      return summaryBlock.content;
+    }
+    return summaryBlock.text ?? '';
+  }
+
+  /** Finds the last summary content block in a message's content array (last-summary-wins). */
+  static findSummaryContentBlock(message) {
+    if (!Array.isArray(message?.content)) {
+      return null;
+    }
+    let lastSummary = null;
+    for (const part of message.content) {
+      // Accepts both new format (content: []) and legacy DB format (text: string)
+      if (part?.type === ContentTypes.SUMMARY && (part.content || part.text)) {
+        lastSummary = part;
+      }
+    }
+    return lastSummary;
+  }
+
  /**
   * Iterate through messages, building an array based on the parentMessageId.
   *
@ -1095,20 +1161,35 @@ class BaseClient {
        break;
      }

-      if (summary && message.summary) {
-        message.role = 'system';
-        message.text = message.summary;
+      let resolved = message;
+      let hasSummary = false;
+      if (summary) {
+        const summaryBlock = BaseClient.findSummaryContentBlock(message);
+        if (summaryBlock) {
+          const summaryText = BaseClient.getSummaryText(summaryBlock);
+          resolved = {
+            ...message,
+            role: 'system',
+            content: [{ type: ContentTypes.TEXT, text: summaryText }],
+            tokenCount: summaryBlock.tokenCount,
+          };
+          hasSummary = true;
+        } else if (message.summary) {
+          resolved = {
+            ...message,
+            role: 'system',
+            content: [{ type: ContentTypes.TEXT, text: message.summary }],
+            tokenCount: message.summaryTokenCount ?? message.tokenCount,
+          };
+          hasSummary = true;
+        }
      }

-      if (summary && message.summaryTokenCount) {
-        message.tokenCount = message.summaryTokenCount;
-      }
-
-      const shouldMap = mapMethod != null && (mapCondition != null ? mapCondition(message) : true);
-      const processedMessage = shouldMap ? mapMethod(message) : message;
+      const shouldMap = mapMethod != null && (mapCondition != null ? mapCondition(resolved) : true);
+      const processedMessage = shouldMap ? mapMethod(resolved) : resolved;
      orderedMessages.push(processedMessage);

-      if (summary && message.summary) {
+      if (hasSummary) {
        break;
      }

--- a/api/app/clients/specs/BaseClient.test.js
+++ b/api/app/clients/specs/BaseClient.test.js
@ -355,7 +355,8 @@ describe('BaseClient', () => {
          id: '3',
          parentMessageId: '2',
          role: 'system',
-          text: 'Summary for Message 3',
+          text: 'Message 3',
+          content: [{ type: 'text', text: 'Summary for Message 3' }],
          summary: 'Summary for Message 3',
        },
        { id: '4', parentMessageId: '3', text: 'Message 4' },
@ -380,7 +381,8 @@ describe('BaseClient', () => {
          id: '4',
          parentMessageId: '3',
          role: 'system',
-          text: 'Summary for Message 4',
+          text: 'Message 4',
+          content: [{ type: 'text', text: 'Summary for Message 4' }],
          summary: 'Summary for Message 4',
        },
        { id: '5', parentMessageId: '4', text: 'Message 5' },
@ -405,12 +407,171 @@ describe('BaseClient', () => {
          id: '4',
          parentMessageId: '3',
          role: 'system',
-          text: 'Summary for Message 4',
+          text: 'Message 4',
+          content: [{ type: 'text', text: 'Summary for Message 4' }],
          summary: 'Summary for Message 4',
        },
        { id: '5', parentMessageId: '4', text: 'Message 5' },
      ]);
    });
+
+    it('should detect summary content block and use it over legacy fields (summary mode)', () => {
+      const messagesWithContentBlock = [
+        { id: '3', parentMessageId: '2', text: 'Message 3' },
+        {
+          id: '2',
+          parentMessageId: '1',
+          text: 'Message 2',
+          content: [
+            { type: 'text', text: 'Original text' },
+            { type: 'summary', text: 'Content block summary', tokenCount: 42 },
+          ],
+        },
+        { id: '1', parentMessageId: null, text: 'Message 1' },
+      ];
+      const result = TestClient.constructor.getMessagesForConversation({
+        messages: messagesWithContentBlock,
+        parentMessageId: '3',
+        summary: true,
+      });
+      expect(result).toHaveLength(2);
+      expect(result[0].role).toBe('system');
+      expect(result[0].content).toEqual([{ type: 'text', text: 'Content block summary' }]);
+      expect(result[0].tokenCount).toBe(42);
+    });
+
+    it('should prefer content block summary over legacy summary field', () => {
+      const messagesWithBoth = [
+        { id: '2', parentMessageId: '1', text: 'Message 2' },
+        {
+          id: '1',
+          parentMessageId: null,
+          text: 'Message 1',
+          summary: 'Legacy summary',
+          summaryTokenCount: 10,
+          content: [{ type: 'summary', text: 'Content block summary', tokenCount: 20 }],
+        },
+      ];
+      const result = TestClient.constructor.getMessagesForConversation({
+        messages: messagesWithBoth,
+        parentMessageId: '2',
+        summary: true,
+      });
+      expect(result).toHaveLength(2);
+      expect(result[0].content).toEqual([{ type: 'text', text: 'Content block summary' }]);
+      expect(result[0].tokenCount).toBe(20);
+    });
+
+    it('should fallback to legacy summary when no content block exists', () => {
+      const messagesWithLegacy = [
+        { id: '2', parentMessageId: '1', text: 'Message 2' },
+        {
+          id: '1',
+          parentMessageId: null,
+          text: 'Message 1',
+          summary: 'Legacy summary only',
+          summaryTokenCount: 15,
+        },
+      ];
+      const result = TestClient.constructor.getMessagesForConversation({
+        messages: messagesWithLegacy,
+        parentMessageId: '2',
+        summary: true,
+      });
+      expect(result).toHaveLength(2);
+      expect(result[0].content).toEqual([{ type: 'text', text: 'Legacy summary only' }]);
+      expect(result[0].tokenCount).toBe(15);
+    });
+  });
+
+  describe('findSummaryContentBlock', () => {
+    it('should find a summary block in the content array', () => {
+      const message = {
+        content: [
+          { type: 'text', text: 'some text' },
+          { type: 'summary', text: 'Summary of conversation', tokenCount: 50 },
+        ],
+      };
+      const result = TestClient.constructor.findSummaryContentBlock(message);
+      expect(result).toBeTruthy();
+      expect(result.text).toBe('Summary of conversation');
+      expect(result.tokenCount).toBe(50);
+    });
+
+    it('should return null when no summary block exists', () => {
+      const message = {
+        content: [
+          { type: 'text', text: 'some text' },
+          { type: 'tool_call', tool_call: {} },
+        ],
+      };
+      expect(TestClient.constructor.findSummaryContentBlock(message)).toBeNull();
+    });
+
+    it('should return null for string content', () => {
+      const message = { content: 'just a string' };
+      expect(TestClient.constructor.findSummaryContentBlock(message)).toBeNull();
+    });
+
+    it('should return null for missing content', () => {
+      expect(TestClient.constructor.findSummaryContentBlock({})).toBeNull();
+      expect(TestClient.constructor.findSummaryContentBlock(null)).toBeNull();
+    });
+
+    it('should skip summary blocks with no text', () => {
+      const message = {
+        content: [{ type: 'summary', tokenCount: 10 }],
+      };
+      expect(TestClient.constructor.findSummaryContentBlock(message)).toBeNull();
+    });
+  });
+
+  describe('handleTokenCountMap', () => {
+    it('should update the last summary content block when multiple summary blocks exist', async () => {
+      const updateMessageInDatabaseSpy = jest
+        .spyOn(TestClient, 'updateMessageInDatabase')
+        .mockResolvedValue(undefined);
+
+      const targetMessage = {
+        messageId: 'assistant-message-1',
+        content: [
+          { type: 'summary', text: 'old-summary-1', tokenCount: 10 },
+          { type: 'text', text: 'middle' },
+          { type: 'summary', text: 'old-summary-2', tokenCount: 20 },
+        ],
+      };
+      const trailingUserMessage = {
+        messageId: 'user-message-1',
+        content: 'latest user message',
+      };
+
+      TestClient.currentMessages = [targetMessage, trailingUserMessage];
+
+      await TestClient.handleTokenCountMap({
+        summaryMessage: {
+          messageId: targetMessage.messageId,
+          content: 'new-summary',
+          tokenCount: 77,
+        },
+        [targetMessage.messageId]: 123,
+      });
+
+      expect(updateMessageInDatabaseSpy).toHaveBeenCalledTimes(1);
+      const updateArg = updateMessageInDatabaseSpy.mock.calls[0][0];
+      expect(updateArg.content[0]).toEqual({
+        type: 'summary',
+        text: 'old-summary-1',
+        tokenCount: 10,
+      });
+      expect(updateArg.content[2]).toEqual(
+        expect.objectContaining({
+          type: 'summary',
+          content: [{ type: 'text', text: 'new-summary' }],
+          tokenCount: 77,
+        }),
+      );
+      expect(updateArg.content[2].createdAt).toBeDefined();
+    });
  });

  describe('sendMessage', () => {
--- a/api/server/controllers/agents/callbacks.js
+++ b/api/server/controllers/agents/callbacks.js
@ -1,7 +1,13 @@
 const { nanoid } = require('nanoid');
 const { logger } = require('@librechat/data-schemas');
-const { Constants, EnvVar, GraphEvents, ToolEndHandler } = require('@librechat/agents');
 const { Tools, StepTypes, FileContext, ErrorTypes } = require('librechat-data-provider');
+const {
+  EnvVar,
+  Constants,
+  GraphEvents,
+  GraphNodeKeys,
+  ToolEndHandler,
+} = require('@librechat/agents');
 const {
  sendEvent,
  GenerationJobManager,
@ -71,6 +77,8 @@ class ModelEndHandler {
        usage.model = modelName;
      }

+      markSummarizationUsage(usage, metadata);
+
      this.collectedUsage.push(usage);
    } catch (error) {
      logger.error('Error handling model end event:', error);
@ -133,6 +141,7 @@ function getDefaultHandlers({
  collectedUsage,
  streamId = null,
  toolExecuteOptions = null,
+  summarizationOptions = null,
 }) {
  if (!res || !aggregateContent) {
    throw new Error(
@ -245,6 +254,46 @@ function getDefaultHandlers({
    handlers[GraphEvents.ON_TOOL_EXECUTE] = createToolExecuteHandler(toolExecuteOptions);
  }

+  if (summarizationOptions?.enabled !== false) {
+    handlers[GraphEvents.ON_SUMMARIZE_START] = {
+      handle: async (_event, data) => {
+        await emitEvent(res, streamId, {
+          event: GraphEvents.ON_SUMMARIZE_START,
+          data,
+        });
+      },
+    };
+    handlers[GraphEvents.ON_SUMMARIZE_DELTA] = {
+      handle: async (_event, data) => {
+        aggregateContent({ event: GraphEvents.ON_SUMMARIZE_DELTA, data });
+        await emitEvent(res, streamId, {
+          event: GraphEvents.ON_SUMMARIZE_DELTA,
+          data,
+        });
+      },
+    };
+    handlers[GraphEvents.ON_SUMMARIZE_COMPLETE] = {
+      handle: async (_event, data) => {
+        aggregateContent({ event: GraphEvents.ON_SUMMARIZE_COMPLETE, data });
+        await emitEvent(res, streamId, {
+          event: GraphEvents.ON_SUMMARIZE_COMPLETE,
+          data,
+        });
+      },
+    };
+  }
+
+  handlers[GraphEvents.ON_AGENT_LOG] = {
+    handle: (_event, data) => {
+      const logFn = typeof logger[data.level] === 'function' ? logger[data.level] : logger.info;
+      logFn(`[agentus:${data.scope}] ${data.message}`, {
+        ...data.data,
+        runId: data.runId,
+        agentId: data.agentId,
+      });
+    },
+  };
+
  return handlers;
 }

@ -668,8 +717,16 @@ function createResponsesToolEndCallback({ req, res, tracker, artifactPromises })
  };
 }

+function markSummarizationUsage(usage, metadata) {
+  const node = metadata?.langgraph_node;
+  if (typeof node === 'string' && node.startsWith(GraphNodeKeys.SUMMARIZE)) {
+    usage.usage_type = 'summarization';
+  }
+}
+
 module.exports = {
  getDefaultHandlers,
  createToolEndCallback,
  createResponsesToolEndCallback,
+  markSummarizationUsage,
 };
--- a/api/server/controllers/agents/client.js
+++ b/api/server/controllers/agents/client.js
@ -25,6 +25,7 @@ const {
  loadAgent: loadAgentFn,
  createMultiAgentMapper,
  filterMalformedContentParts,
+  hydrateMissingIndexTokenCounts,
 } = require('@librechat/api');
 const {
  Callback,
@ -61,9 +62,6 @@ class AgentClient extends BaseClient {
     * @type {string} */
    this.clientName = EModelEndpoint.agents;

-    /** @type {'discard' | 'summarize'} */
-    this.contextStrategy = 'discard';
-
    /** @deprecated @type {true} - Is a Chat Completion Request */
    this.isChatCompletion = true;

@ -215,7 +213,6 @@ class AgentClient extends BaseClient {
          }))
        : []),
    ];
-
    if (this.options.attachments) {
      const attachments = await this.options.attachments;
      const latestMessage = orderedMessages[orderedMessages.length - 1];
@ -242,6 +239,9 @@ class AgentClient extends BaseClient {
      );
    }

+    /** @type {Record<number, number>} */
+    const canonicalTokenCountMap = {};
+    let promptTokenTotal = 0;
    const formattedMessages = orderedMessages.map((message, i) => {
      const formattedMessage = formatMessage({
        message,
@ -261,8 +261,7 @@ class AgentClient extends BaseClient {
        }
      }

-      const needsTokenCount =
-        (this.contextStrategy && !orderedMessages[i].tokenCount) || message.fileContext;
+      const needsTokenCount = !orderedMessages[i].tokenCount || message.fileContext;

      /* If tokens were never counted, or, is a Vision request and the message has files, count again */
      if (needsTokenCount || (this.isVisionModel && (message.image_urls || message.files))) {
@ -288,9 +287,18 @@ class AgentClient extends BaseClient {
        }
      }

+      const tokenCount = Number(orderedMessages[i].tokenCount);
+      const normalizedTokenCount = Number.isFinite(tokenCount) && tokenCount > 0 ? tokenCount : 0;
+      canonicalTokenCountMap[i] = normalizedTokenCount;
+      promptTokenTotal += normalizedTokenCount;
+
      return formattedMessage;
    });

+    payload = formattedMessages;
+    messages = orderedMessages;
+    promptTokens = promptTokenTotal;
+
    /**
     * Build shared run context - applies to ALL agents in the run.
     * This includes: file context (latest message), augmented prompt (RAG), memory context.
@ -323,16 +331,8 @@ class AgentClient extends BaseClient {
    /** @type {Record<string, number> | undefined} */
    let tokenCountMap;

-    if (this.contextStrategy) {
-      ({ payload, promptTokens, tokenCountMap, messages } = await this.handleContextStrategy({
-        orderedMessages,
-        formattedMessages,
-      }));
-    }
-
-    for (let i = 0; i < messages.length; i++) {
-      this.indexTokenCountMap[i] = messages[i].tokenCount;
-    }
+    /** Preserve canonical pre-format token counts for all history entering graph formatting */
+    this.indexTokenCountMap = canonicalTokenCountMap;

    const result = {
      tokenCountMap,
@ -743,11 +743,17 @@ class AgentClient extends BaseClient {
      };

      const toolSet = buildToolSet(this.options.agent);
-      let { messages: initialMessages, indexTokenCountMap } = formatAgentMessages(
-        payload,
-        this.indexTokenCountMap,
-        toolSet,
-      );
+      const tokenCounter = createTokenCounter(this.getEncoding());
+      let {
+        messages: initialMessages,
+        indexTokenCountMap,
+        summary: initialSummary,
+      } = formatAgentMessages(payload, this.indexTokenCountMap, toolSet);
+      indexTokenCountMap = hydrateMissingIndexTokenCounts({
+        messages: initialMessages,
+        indexTokenCountMap,
+        tokenCounter,
+      });

      /**
       * @param {BaseMessage[]} messages
@ -805,12 +811,14 @@ class AgentClient extends BaseClient {
          agents,
          messages,
          indexTokenCountMap,
+          initialSummary,
          runId: this.responseMessageId,
          signal: abortController.signal,
          customHandlers: this.options.eventHandlers,
          requestBody: config.configurable.requestBody,
          user: createSafeUser(this.options.req?.user),
-          tokenCounter: createTokenCounter(this.getEncoding()),
+          summarizationConfig: appConfig?.summarization,
+          tokenCounter,
        });

        if (!run) {
@ -1056,6 +1064,7 @@ class AgentClient extends BaseClient {
        titlePrompt: endpointConfig?.titlePrompt,
        titlePromptTemplate: endpointConfig?.titlePromptTemplate,
        chainOptions: {
+          runName: 'TitleRun',
          signal: abortController.signal,
          callbacks: [
            {
--- a/api/server/controllers/agents/client.test.js
+++ b/api/server/controllers/agents/client.test.js
@ -1818,7 +1818,7 @@ describe('AgentClient - titleConvo', () => {

      /** Traversal stops at msg-2 (has summary), so we get msg-4 -> msg-3 -> msg-2 */
      expect(result).toHaveLength(3);
-      expect(result[0].text).toBe('Summary of conversation');
+      expect(result[0].content).toEqual([{ type: 'text', text: 'Summary of conversation' }]);
      expect(result[0].role).toBe('system');
      expect(result[0].mapped).toBe(true);
      expect(result[1].mapped).toBe(true);
--- a/api/server/controllers/agents/openai.js
+++ b/api/server/controllers/agents/openai.js
@ -1,7 +1,7 @@
 const { nanoid } = require('nanoid');
 const { logger } = require('@librechat/data-schemas');
-const { Callback, ToolEndHandler, formatAgentMessages } = require('@librechat/agents');
 const { EModelEndpoint, ResourceType, PermissionBits } = require('librechat-data-provider');
+const { Callback, ToolEndHandler, formatAgentMessages } = require('@librechat/agents');
 const {
  writeSSE,
  createRun,
@ -22,7 +22,10 @@ const {
  isChatCompletionValidationFailure,
 } = require('@librechat/api');
 const { loadAgentTools, loadToolsForExecution } = require('~/server/services/ToolService');
-const { createToolEndCallback } = require('~/server/controllers/agents/callbacks');
+const {
+  createToolEndCallback,
+  markSummarizationUsage,
+} = require('~/server/controllers/agents/callbacks');
 const { findAccessibleResources } = require('~/server/services/PermissionService');
 const db = require('~/models');

@ -266,14 +269,16 @@ const OpenAIChatCompletionController = async (req, res) => {
      toolEndCallback,
    };

+    const summarizationConfig = appConfig?.summarization;
+
    const openaiMessages = convertMessages(request.messages);

    const toolSet = buildToolSet(primaryConfig);
-    const { messages: formattedMessages, indexTokenCountMap } = formatAgentMessages(
-      openaiMessages,
-      {},
-      toolSet,
-    );
+    const {
+      messages: formattedMessages,
+      indexTokenCountMap,
+      summary: initialSummary,
+    } = formatAgentMessages(openaiMessages, {}, toolSet);

    /**
     * Create a simple handler that processes data
@ -416,15 +421,18 @@ const OpenAIChatCompletionController = async (req, res) => {
      }),

      // Usage tracking
-      on_chat_model_end: createHandler((data) => {
-        const usage = data?.output?.usage_metadata;
-        if (usage) {
-          collectedUsage.push(usage);
-          const target = isStreaming ? tracker : aggregator;
-          target.usage.promptTokens += usage.input_tokens ?? 0;
-          target.usage.completionTokens += usage.output_tokens ?? 0;
-        }
-      }),
+      on_chat_model_end: {
+        handle: (_event, data, metadata) => {
+          const usage = data?.output?.usage_metadata;
+          if (usage) {
+            markSummarizationUsage(usage, metadata);
+            collectedUsage.push(usage);
+            const target = isStreaming ? tracker : aggregator;
+            target.usage.promptTokens += usage.input_tokens ?? 0;
+            target.usage.completionTokens += usage.output_tokens ?? 0;
+          }
+        },
+      },
      on_run_step_completed: createHandler(),
      // Use proper ToolEndHandler for processing artifacts (images, file citations, code output)
      on_tool_end: new ToolEndHandler(toolEndCallback, logger),
@ -434,6 +442,31 @@ const OpenAIChatCompletionController = async (req, res) => {
      on_custom_event: createHandler(),
      // Event-driven tool execution handler
      on_tool_execute: createToolExecuteHandler(toolExecuteOptions),
+      ...(summarizationConfig?.enabled !== false
+        ? {
+            on_summarize_start: {
+              handle: async (_event, data) => {
+                if (isStreaming && !res.writableEnded) {
+                  res.write(`event: on_summarize_start\ndata: ${JSON.stringify(data)}\n\n`);
+                }
+              },
+            },
+            on_summarize_delta: {
+              handle: async (_event, data) => {
+                if (isStreaming && !res.writableEnded) {
+                  res.write(`event: on_summarize_delta\ndata: ${JSON.stringify(data)}\n\n`);
+                }
+              },
+            },
+            on_summarize_complete: {
+              handle: async (_event, data) => {
+                if (isStreaming && !res.writableEnded) {
+                  res.write(`event: on_summarize_complete\ndata: ${JSON.stringify(data)}\n\n`);
+                }
+              },
+            },
+          }
+        : {}),
    };

    // Create and run the agent
@ -446,7 +479,9 @@ const OpenAIChatCompletionController = async (req, res) => {
      agents: [primaryConfig],
      messages: formattedMessages,
      indexTokenCountMap,
+      initialSummary,
      runId: responseId,
+      summarizationConfig,
      signal: abortController.signal,
      customHandlers: handlers,
      requestBody: {
--- a/api/server/controllers/agents/responses.js
+++ b/api/server/controllers/agents/responses.js
@ -33,6 +33,7 @@ const {
 const {
  createResponsesToolEndCallback,
  createToolEndCallback,
+  markSummarizationUsage,
 } = require('~/server/controllers/agents/callbacks');
 const { loadAgentTools, loadToolsForExecution } = require('~/server/services/ToolService');
 const { findAccessibleResources } = require('~/server/services/PermissionService');
@ -49,6 +50,17 @@ function setAppConfig(config) {
  appConfig = config;
 }

+const agentLogHandler = {
+  handle: (_event, data) => {
+    const logFn = typeof logger[data.level] === 'function' ? logger[data.level] : logger.info;
+    logFn(`[agentus:${data.scope}] ${data.message}`, {
+      ...data.data,
+      runId: data.runId,
+      agentId: data.agentId,
+    });
+  },
+};
+
 /**
 * Creates a tool loader function for the agent.
 * @param {AbortSignal} signal - The abort signal
@ -277,6 +289,7 @@ const createResponse = async (req, res) => {
  const request = validation.request;
  const agentId = request.model;
  const isStreaming = request.stream === true;
+  const summarizationConfig = req.config?.summarization;

  // Look up the agent
  const agent = await db.getAgent({ id: agentId });
@ -374,11 +387,11 @@ const createResponse = async (req, res) => {
    const allMessages = [...previousMessages, ...inputMessages];

    const toolSet = buildToolSet(primaryConfig);
-    const { messages: formattedMessages, indexTokenCountMap } = formatAgentMessages(
-      allMessages,
-      {},
-      toolSet,
-    );
+    const {
+      messages: formattedMessages,
+      indexTokenCountMap,
+      summary: initialSummary,
+    } = formatAgentMessages(allMessages, {}, toolSet);

    // Create tracker for streaming or aggregator for non-streaming
    const tracker = actuallyStreaming ? createResponseTracker() : null;
@ -441,10 +454,11 @@ const createResponse = async (req, res) => {
        on_run_step: responsesHandlers.on_run_step,
        on_run_step_delta: responsesHandlers.on_run_step_delta,
        on_chat_model_end: {
-          handle: (event, data) => {
+          handle: (event, data, metadata) => {
            responsesHandlers.on_chat_model_end.handle(event, data);
            const usage = data?.output?.usage_metadata;
            if (usage) {
+              markSummarizationUsage(usage, metadata);
              collectedUsage.push(usage);
            }
          },
@ -456,6 +470,32 @@ const createResponse = async (req, res) => {
        on_agent_update: { handle: () => {} },
        on_custom_event: { handle: () => {} },
        on_tool_execute: createToolExecuteHandler(toolExecuteOptions),
+        on_agent_log: agentLogHandler,
+        ...(summarizationConfig?.enabled !== false
+          ? {
+              on_summarize_start: {
+                handle: async (_event, data) => {
+                  if (actuallyStreaming && !res.writableEnded) {
+                    res.write(`event: on_summarize_start\ndata: ${JSON.stringify(data)}\n\n`);
+                  }
+                },
+              },
+              on_summarize_delta: {
+                handle: async (_event, data) => {
+                  if (actuallyStreaming && !res.writableEnded) {
+                    res.write(`event: on_summarize_delta\ndata: ${JSON.stringify(data)}\n\n`);
+                  }
+                },
+              },
+              on_summarize_complete: {
+                handle: async (_event, data) => {
+                  if (actuallyStreaming && !res.writableEnded) {
+                    res.write(`event: on_summarize_complete\ndata: ${JSON.stringify(data)}\n\n`);
+                  }
+                },
+              },
+            }
+          : {}),
      };

      // Create and run the agent
@ -466,7 +506,9 @@ const createResponse = async (req, res) => {
        agents: [primaryConfig],
        messages: formattedMessages,
        indexTokenCountMap,
+        initialSummary,
        runId: responseId,
+        summarizationConfig,
        signal: abortController.signal,
        customHandlers: handlers,
        requestBody: {
@ -597,10 +639,11 @@ const createResponse = async (req, res) => {
        on_run_step: aggregatorHandlers.on_run_step,
        on_run_step_delta: aggregatorHandlers.on_run_step_delta,
        on_chat_model_end: {
-          handle: (event, data) => {
+          handle: (event, data, metadata) => {
            aggregatorHandlers.on_chat_model_end.handle(event, data);
            const usage = data?.output?.usage_metadata;
            if (usage) {
+              markSummarizationUsage(usage, metadata);
              collectedUsage.push(usage);
            }
          },
@ -612,6 +655,14 @@ const createResponse = async (req, res) => {
        on_agent_update: { handle: () => {} },
        on_custom_event: { handle: () => {} },
        on_tool_execute: createToolExecuteHandler(toolExecuteOptions),
+        on_agent_log: agentLogHandler,
+        ...(summarizationConfig?.enabled !== false
+          ? {
+              on_summarize_start: { handle: () => {} },
+              on_summarize_delta: { handle: () => {} },
+              on_summarize_complete: { handle: () => {} },
+            }
+          : {}),
      };

      const userId = req.user?.id ?? 'api-user';
@ -621,7 +672,9 @@ const createResponse = async (req, res) => {
        agents: [primaryConfig],
        messages: formattedMessages,
        indexTokenCountMap,
+        initialSummary,
        runId: responseId,
+        summarizationConfig,
        signal: abortController.signal,
        customHandlers: handlers,
        requestBody: {
--- a/api/server/routes/files/files.agents.test.js
+++ b/api/server/routes/files/files.agents.test.js
@ -2,15 +2,14 @@ const express = require('express');
 const request = require('supertest');
 const mongoose = require('mongoose');
 const { v4: uuidv4 } = require('uuid');
-const { createMethods } = require('@librechat/data-schemas');
 const { MongoMemoryServer } = require('mongodb-memory-server');
+const { createMethods, SystemCapabilities } = require('@librechat/data-schemas');
 const {
  SystemRoles,
  AccessRoleIds,
  ResourceType,
  PrincipalType,
 } = require('librechat-data-provider');
-const { SystemCapabilities } = require('@librechat/data-schemas');
 const { createAgent, createFile } = require('~/models');

 // Only mock the external dependencies that we don't want to test
--- a/api/server/services/Endpoints/agents/initialize.js
+++ b/api/server/services/Endpoints/agents/initialize.js
@ -78,6 +78,14 @@ function createToolLoader(signal, streamId = null, definitionsOnly = false) {
  };
 }

+/**
+ * Initializes the AgentClient for a given request/response cycle.
+ * @param {Object} params
+ * @param {Express.Request} params.req
+ * @param {Express.Response} params.res
+ * @param {AbortSignal} params.signal
+ * @param {Object} params.endpointOption
+ */
 const initializeClient = async ({ req, res, signal, endpointOption }) => {
  if (!endpointOption) {
    throw new Error('Endpoint option not provided');
@ -131,9 +139,13 @@ const initializeClient = async ({ req, res, signal, endpointOption }) => {
    toolEndCallback,
  };

+  const summarizationOptions =
+    appConfig?.summarization?.enabled === false ? { enabled: false } : { enabled: true };
+
  const eventHandlers = getDefaultHandlers({
    res,
    toolExecuteOptions,
+    summarizationOptions,
    aggregateContent,
    toolEndCallback,
    collectedUsage,
--- a/api/server/services/Endpoints/index.js
+++ b/api/server/services/Endpoints/index.js
@ -1,77 +0,0 @@
-const { Providers } = require('@librechat/agents');
-const { EModelEndpoint } = require('librechat-data-provider');
-const { getCustomEndpointConfig } = require('@librechat/api');
-const initAnthropic = require('~/server/services/Endpoints/anthropic/initialize');
-const getBedrockOptions = require('~/server/services/Endpoints/bedrock/options');
-const initOpenAI = require('~/server/services/Endpoints/openAI/initialize');
-const initCustom = require('~/server/services/Endpoints/custom/initialize');
-const initGoogle = require('~/server/services/Endpoints/google/initialize');
-
-/** Check if the provider is a known custom provider
- * @param {string | undefined} [provider] - The provider string
- * @returns {boolean} - True if the provider is a known custom provider, false otherwise
- */
-function isKnownCustomProvider(provider) {
-  return [Providers.XAI, Providers.DEEPSEEK, Providers.OPENROUTER, Providers.MOONSHOT].includes(
-    provider?.toLowerCase() || '',
-  );
-}
-
-const providerConfigMap = {
-  [Providers.XAI]: initCustom,
-  [Providers.DEEPSEEK]: initCustom,
-  [Providers.MOONSHOT]: initCustom,
-  [Providers.OPENROUTER]: initCustom,
-  [EModelEndpoint.openAI]: initOpenAI,
-  [EModelEndpoint.google]: initGoogle,
-  [EModelEndpoint.azureOpenAI]: initOpenAI,
-  [EModelEndpoint.anthropic]: initAnthropic,
-  [EModelEndpoint.bedrock]: getBedrockOptions,
-};
-
-/**
- * Get the provider configuration and override endpoint based on the provider string
- * @param {Object} params
- * @param {string} params.provider - The provider string
- * @param {AppConfig} params.appConfig - The application configuration
- * @returns {{
- * getOptions: (typeof providerConfigMap)[keyof typeof providerConfigMap],
- * overrideProvider: string,
- * customEndpointConfig?: TEndpoint
- * }}
- */
-function getProviderConfig({ provider, appConfig }) {
-  let getOptions = providerConfigMap[provider];
-  let overrideProvider = provider;
-  /** @type {TEndpoint | undefined} */
-  let customEndpointConfig;
-
-  if (!getOptions && providerConfigMap[provider.toLowerCase()] != null) {
-    overrideProvider = provider.toLowerCase();
-    getOptions = providerConfigMap[overrideProvider];
-  } else if (!getOptions) {
-    customEndpointConfig = getCustomEndpointConfig({ endpoint: provider, appConfig });
-    if (!customEndpointConfig) {
-      throw new Error(`Provider ${provider} not supported`);
-    }
-    getOptions = initCustom;
-    overrideProvider = Providers.OPENAI;
-  }
-
-  if (isKnownCustomProvider(overrideProvider) && !customEndpointConfig) {
-    customEndpointConfig = getCustomEndpointConfig({ endpoint: provider, appConfig });
-    if (!customEndpointConfig) {
-      throw new Error(`Provider ${provider} not supported`);
-    }
-  }
-
-  return {
-    getOptions,
-    overrideProvider,
-    customEndpointConfig,
-  };
-}
-
-module.exports = {
-  getProviderConfig,
-};
--- a/client/src/a11y/LiveAnnouncer.tsx
+++ b/client/src/a11y/LiveAnnouncer.tsx
@ -21,6 +21,9 @@ const LiveAnnouncer: React.FC<LiveAnnouncerProps> = ({ children }) => {
      start: localize('com_a11y_start'),
      end: localize('com_a11y_end'),
      composing: localize('com_a11y_ai_composing'),
+      summarize_started: localize('com_a11y_summarize_started'),
+      summarize_completed: localize('com_a11y_summarize_completed'),
+      summarize_failed: localize('com_a11y_summarize_failed'),
    }),
    [localize],
  );
--- a/client/src/components/Chat/Messages/Content/Part.tsx
+++ b/client/src/components/Chat/Messages/Content/Part.tsx
@ -8,7 +8,15 @@ import {
 } from 'librechat-data-provider';
 import { memo } from 'react';
 import type { TMessageContentParts, TAttachment } from 'librechat-data-provider';
-import { OpenAIImageGen, EmptyText, Reasoning, ExecuteCode, AgentUpdate, Text } from './Parts';
+import {
+  OpenAIImageGen,
+  ExecuteCode,
+  AgentUpdate,
+  EmptyText,
+  Reasoning,
+  Summary,
+  Text,
+} from './Parts';
 import { ErrorMessage } from './MessageContent';
 import RetrievalCall from './RetrievalCall';
 import { getCachedPreview } from '~/utils';
@ -100,6 +108,16 @@ const Part = memo(function Part({
      return null;
    }
    return <Reasoning reasoning={reasoning} isLast={isLast ?? false} />;
+  } else if (part.type === ContentTypes.SUMMARY) {
+    return (
+      <Summary
+        content={part.content}
+        model={part.model}
+        provider={part.provider}
+        tokenCount={part.tokenCount}
+        summarizing={part.summarizing}
+      />
+    );
  } else if (part.type === ContentTypes.TOOL_CALL) {
    const toolCall = part[ContentTypes.TOOL_CALL];

--- a/client/src/components/Chat/Messages/Content/Parts/Summary.tsx
+++ b/client/src/components/Chat/Messages/Content/Parts/Summary.tsx
@ -0,0 +1,318 @@
+import { memo, useMemo, useState, useCallback, useRef, useId, useEffect } from 'react';
+import { useAtomValue } from 'jotai';
+import { Clipboard, CheckMark, TooltipAnchor } from '@librechat/client';
+import { ScrollText, ChevronDown, ChevronUp } from 'lucide-react';
+import type { MouseEvent, FocusEvent } from 'react';
+import { fontSizeAtom } from '~/store/fontSize';
+import { useMessageContext } from '~/Providers';
+import { useLocalize } from '~/hooks';
+import { cn } from '~/utils';
+
+function useCopyToClipboard(content?: string) {
+  const [isCopied, setIsCopied] = useState(false);
+  const timerRef = useRef<ReturnType<typeof setTimeout>>();
+  useEffect(() => () => clearTimeout(timerRef.current), []);
+  const handleCopy = useCallback(
+    (e: MouseEvent<HTMLButtonElement>) => {
+      e.stopPropagation();
+      if (content) {
+        navigator.clipboard.writeText(content);
+        clearTimeout(timerRef.current);
+        setIsCopied(true);
+        timerRef.current = setTimeout(() => setIsCopied(false), 2000);
+      }
+    },
+    [content],
+  );
+  return { isCopied, handleCopy };
+}
+
+type ContentBlock = { type?: string; text?: string };
+
+type SummaryProps = {
+  content?: ContentBlock[];
+  model?: string;
+  provider?: string;
+  tokenCount?: number;
+  summarizing?: boolean;
+};
+
+const SummaryContent = memo(({ children, meta }: { children: React.ReactNode; meta?: string }) => {
+  const fontSize = useAtomValue(fontSizeAtom);
+
+  return (
+    <div className="relative rounded-3xl border border-border-medium bg-surface-tertiary p-4 pb-10 text-text-secondary">
+      {meta && <span className="mb-1 block text-xs text-text-secondary">{meta}</span>}
+      <p className={cn('whitespace-pre-wrap leading-[26px]', fontSize)}>{children}</p>
+    </div>
+  );
+});
+
+const SummaryButton = memo(
+  ({
+    isExpanded,
+    onClick,
+    label,
+    content,
+    contentId,
+    showCopyButton = true,
+  }: {
+    isExpanded: boolean;
+    onClick: (e: MouseEvent<HTMLButtonElement>) => void;
+    label: string;
+    content?: string;
+    contentId: string;
+    showCopyButton?: boolean;
+  }) => {
+    const localize = useLocalize();
+    const fontSize = useAtomValue(fontSizeAtom);
+    const { isCopied, handleCopy } = useCopyToClipboard(content);
+
+    return (
+      <div className="group/summary flex w-full items-center justify-between gap-2">
+        <button
+          type="button"
+          onClick={onClick}
+          aria-expanded={isExpanded}
+          aria-controls={contentId}
+          className={cn(
+            'group/button flex flex-1 items-center justify-start rounded-lg leading-[18px]',
+            fontSize,
+          )}
+        >
+          <span className="relative mr-1.5 inline-flex h-[18px] w-[18px] items-center justify-center">
+            <ScrollText
+              className="icon-sm absolute text-text-secondary opacity-100 transition-opacity group-hover/button:opacity-0"
+              aria-hidden="true"
+            />
+            <ChevronDown
+              className={cn(
+                'icon-sm absolute transform-gpu text-text-primary opacity-0 transition-all duration-300 group-hover/button:opacity-100',
+                isExpanded && 'rotate-180',
+              )}
+              aria-hidden="true"
+            />
+          </span>
+          <span>{label}</span>
+        </button>
+        {content && showCopyButton && (
+          <button
+            type="button"
+            onClick={handleCopy}
+            aria-label={
+              isCopied ? localize('com_ui_copied_to_clipboard') : localize('com_ui_copy_summary')
+            }
+            className={cn(
+              'rounded-lg p-1.5 text-text-secondary-alt',
+              isExpanded
+                ? 'opacity-0 group-focus-within/summary-container:opacity-100 group-hover/summary-container:opacity-100'
+                : 'opacity-0',
+              'hover:bg-surface-hover hover:text-text-primary',
+              'focus-visible:opacity-100 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-black dark:focus-visible:ring-white',
+            )}
+          >
+            <span className="sr-only">
+              {isCopied ? localize('com_ui_copied_to_clipboard') : localize('com_ui_copy_summary')}
+            </span>
+            {isCopied ? (
+              <CheckMark className="h-[18px] w-[18px]" aria-hidden="true" />
+            ) : (
+              <Clipboard size="19" aria-hidden="true" />
+            )}
+          </button>
+        )}
+      </div>
+    );
+  },
+);
+
+const FloatingSummaryBar = memo(
+  ({
+    isVisible,
+    isExpanded,
+    onClick,
+    content,
+    contentId,
+  }: {
+    isVisible: boolean;
+    isExpanded: boolean;
+    onClick: (e: MouseEvent<HTMLButtonElement>) => void;
+    content?: string;
+    contentId: string;
+  }) => {
+    const localize = useLocalize();
+    const { isCopied, handleCopy } = useCopyToClipboard(content);
+
+    const collapseTooltip = isExpanded
+      ? localize('com_ui_collapse_summary')
+      : localize('com_ui_expand_summary');
+
+    const copyTooltip = isCopied
+      ? localize('com_ui_copied_to_clipboard')
+      : localize('com_ui_copy_summary');
+
+    return (
+      <div
+        className={cn(
+          'absolute bottom-3 right-3 flex items-center gap-2 transition-opacity duration-150',
+          isVisible ? 'opacity-100' : 'pointer-events-none opacity-0',
+        )}
+      >
+        <TooltipAnchor
+          description={collapseTooltip}
+          render={
+            <button
+              type="button"
+              tabIndex={isVisible ? 0 : -1}
+              onClick={onClick}
+              aria-label={collapseTooltip}
+              aria-controls={contentId}
+              className={cn(
+                'flex items-center justify-center rounded-lg bg-surface-secondary p-1.5 text-text-secondary-alt shadow-sm',
+                'hover:bg-surface-hover hover:text-text-primary',
+                'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-border-heavy',
+              )}
+            >
+              {isExpanded ? (
+                <ChevronUp className="h-[18px] w-[18px]" aria-hidden="true" />
+              ) : (
+                <ChevronDown className="h-[18px] w-[18px]" aria-hidden="true" />
+              )}
+            </button>
+          }
+        />
+        {content && (
+          <TooltipAnchor
+            description={copyTooltip}
+            render={
+              <button
+                type="button"
+                tabIndex={isVisible ? 0 : -1}
+                onClick={handleCopy}
+                aria-label={copyTooltip}
+                className={cn(
+                  'flex items-center justify-center rounded-lg bg-surface-secondary p-1.5 text-text-secondary-alt shadow-sm',
+                  'hover:bg-surface-hover hover:text-text-primary',
+                  'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-border-heavy',
+                )}
+              >
+                {isCopied ? (
+                  <CheckMark className="h-[18px] w-[18px]" aria-hidden="true" />
+                ) : (
+                  <Clipboard size="18" aria-hidden="true" />
+                )}
+              </button>
+            }
+          />
+        )}
+      </div>
+    );
+  },
+);
+
+const Summary = memo(({ content, model, provider, tokenCount, summarizing }: SummaryProps) => {
+  const contentId = useId();
+  const localize = useLocalize();
+  const [isExpanded, setIsExpanded] = useState(false);
+  const [isBarVisible, setIsBarVisible] = useState(false);
+  const containerRef = useRef<HTMLDivElement>(null);
+  const { isSubmitting, isLatestMessage } = useMessageContext();
+
+  const text = useMemo(() => (content ?? []).map((block) => block.text ?? '').join(''), [content]);
+
+  const handleClick = useCallback((e: MouseEvent<HTMLButtonElement>) => {
+    e.preventDefault();
+    setIsExpanded((prev) => !prev);
+  }, []);
+
+  const handleFocus = useCallback(() => setIsBarVisible(true), []);
+  const handleBlur = useCallback((e: FocusEvent) => {
+    if (!containerRef.current?.contains(e.relatedTarget as Node)) {
+      setIsBarVisible(false);
+    }
+  }, []);
+  const handleMouseEnter = useCallback(() => setIsBarVisible(true), []);
+  const handleMouseLeave = useCallback(() => {
+    if (!containerRef.current?.contains(document.activeElement)) {
+      setIsBarVisible(false);
+    }
+  }, []);
+
+  const effectiveIsSubmitting = isLatestMessage ? isSubmitting : false;
+  const isActivelyStreaming = !!summarizing && !!effectiveIsSubmitting;
+
+  const meta = useMemo(() => {
+    const parts: string[] = [];
+    if (provider || model) {
+      parts.push([provider, model].filter(Boolean).join('/'));
+    }
+    if (tokenCount != null && tokenCount > 0) {
+      parts.push(`${tokenCount} ${localize('com_ui_tokens')}`);
+    }
+    return parts.length > 0 ? parts.join(' \u00b7 ') : undefined;
+  }, [model, provider, tokenCount, localize]);
+
+  const label = useMemo(
+    () =>
+      isActivelyStreaming
+        ? localize('com_ui_summarizing')
+        : localize('com_ui_conversation_summarized'),
+    [isActivelyStreaming, localize],
+  );
+
+  if (!summarizing && !text) {
+    return null;
+  }
+
+  return (
+    <div
+      ref={containerRef}
+      className="group/summary"
+      onMouseEnter={handleMouseEnter}
+      onMouseLeave={handleMouseLeave}
+      onFocus={handleFocus}
+      onBlur={handleBlur}
+    >
+      <div className="group/summary-container">
+        <div className="mb-2 pb-2 pt-2">
+          <SummaryButton
+            isExpanded={isExpanded}
+            onClick={handleClick}
+            label={label}
+            content={text}
+            contentId={contentId}
+            showCopyButton={!isActivelyStreaming}
+          />
+        </div>
+        <div
+          id={contentId}
+          role="group"
+          aria-label={label}
+          aria-hidden={!isExpanded || undefined}
+          className={cn('grid transition-all duration-300 ease-out', isExpanded && 'mb-4')}
+          style={{
+            gridTemplateRows: isExpanded ? '1fr' : '0fr',
+          }}
+        >
+          <div className="relative overflow-hidden">
+            <SummaryContent meta={meta}>{text}</SummaryContent>
+            <FloatingSummaryBar
+              isVisible={isBarVisible && isExpanded}
+              isExpanded={isExpanded}
+              onClick={handleClick}
+              content={text}
+              contentId={contentId}
+            />
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+});
+
+SummaryContent.displayName = 'SummaryContent';
+SummaryButton.displayName = 'SummaryButton';
+FloatingSummaryBar.displayName = 'FloatingSummaryBar';
+Summary.displayName = 'Summary';
+
+export default Summary;
--- a/client/src/components/Chat/Messages/Content/Parts/index.ts
+++ b/client/src/components/Chat/Messages/Content/Parts/index.ts
@ -6,5 +6,6 @@ export { default as Reasoning } from './Reasoning';
 export { default as EmptyText } from './EmptyText';
 export { default as LogContent } from './LogContent';
 export { default as ExecuteCode } from './ExecuteCode';
+export { default as Summary } from './Summary';
 export { default as AgentUpdate } from './AgentUpdate';
 export { default as EditTextPart } from './EditTextPart';
--- a/client/src/hooks/SSE/tests/useStepHandler.spec.ts
+++ b/client/src/hooks/SSE/tests/useStepHandler.spec.ts
@ -1,5 +1,5 @@
 import { renderHook, act } from '@testing-library/react';
-import { StepTypes, ContentTypes, ToolCallTypes } from 'librechat-data-provider';
+import { StepTypes, StepEvents, ContentTypes, ToolCallTypes } from 'librechat-data-provider';
 import type {
  TMessageContentParts,
  EventSubmission,
@ -155,7 +155,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -174,7 +174,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(consoleSpy).toHaveBeenCalledWith('No message id found in run step event');
@ -194,7 +194,7 @@ describe('useStepHandler', () => {
      });

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -210,7 +210,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -235,7 +235,7 @@ describe('useStepHandler', () => {

      act(() => {
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta(stepId, 'Hello') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta(stepId, 'Hello') },
          submission,
        );
      });
@ -245,7 +245,7 @@ describe('useStepHandler', () => {
      const runStep = createRunStep({ id: stepId });

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -266,7 +266,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission({ userMessage: userMsg });

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -289,7 +289,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      const lastCall = mockSetMessages.mock.calls[mockSetMessages.mock.calls.length - 1][0];
@ -315,7 +315,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -330,7 +330,10 @@ describe('useStepHandler', () => {
      };

      act(() => {
-        result.current.stepHandler({ event: 'on_agent_update', data: agentUpdate }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_AGENT_UPDATE, data: agentUpdate },
+          submission,
+        );
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -352,7 +355,10 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_agent_update', data: agentUpdate }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_AGENT_UPDATE, data: agentUpdate },
+          submission,
+        );
      });

      expect(consoleSpy).toHaveBeenCalledWith('No message id found in agent update event');
@ -371,7 +377,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -379,7 +385,10 @@ describe('useStepHandler', () => {
      const messageDelta = createMessageDelta('step-1', 'Hello');

      act(() => {
-        result.current.stepHandler({ event: 'on_message_delta', data: messageDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_MESSAGE_DELTA, data: messageDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -397,7 +406,10 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_message_delta', data: messageDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_MESSAGE_DELTA, data: messageDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).not.toHaveBeenCalled();
@ -413,19 +425,19 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      act(() => {
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta('step-1', 'Hello ') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta('step-1', 'Hello ') },
          submission,
        );
      });

      act(() => {
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta('step-1', 'World') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta('step-1', 'World') },
          submission,
        );
      });
@ -447,7 +459,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -458,7 +470,10 @@ describe('useStepHandler', () => {
      };

      act(() => {
-        result.current.stepHandler({ event: 'on_message_delta', data: messageDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_MESSAGE_DELTA, data: messageDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).not.toHaveBeenCalled();
@ -476,7 +491,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -485,7 +500,7 @@ describe('useStepHandler', () => {

      act(() => {
        result.current.stepHandler(
-          { event: 'on_reasoning_delta', data: reasoningDelta },
+          { event: StepEvents.ON_REASONING_DELTA, data: reasoningDelta },
          submission,
        );
      });
@ -506,7 +521,7 @@ describe('useStepHandler', () => {

      act(() => {
        result.current.stepHandler(
-          { event: 'on_reasoning_delta', data: reasoningDelta },
+          { event: StepEvents.ON_REASONING_DELTA, data: reasoningDelta },
          submission,
        );
      });
@ -524,19 +539,19 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      act(() => {
        result.current.stepHandler(
-          { event: 'on_reasoning_delta', data: createReasoningDelta('step-1', 'First ') },
+          { event: StepEvents.ON_REASONING_DELTA, data: createReasoningDelta('step-1', 'First ') },
          submission,
        );
      });

      act(() => {
        result.current.stepHandler(
-          { event: 'on_reasoning_delta', data: createReasoningDelta('step-1', 'thought') },
+          { event: StepEvents.ON_REASONING_DELTA, data: createReasoningDelta('step-1', 'thought') },
          submission,
        );
      });
@ -560,7 +575,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -574,7 +589,10 @@ describe('useStepHandler', () => {
      };

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step_delta', data: runStepDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_RUN_STEP_DELTA, data: runStepDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -593,7 +611,10 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step_delta', data: runStepDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_RUN_STEP_DELTA, data: runStepDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).not.toHaveBeenCalled();
@ -609,7 +630,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -625,7 +646,10 @@ describe('useStepHandler', () => {
      };

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step_delta', data: runStepDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_RUN_STEP_DELTA, data: runStepDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -649,7 +673,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -671,8 +695,8 @@ describe('useStepHandler', () => {
      act(() => {
        result.current.stepHandler(
          {
-            event: 'on_run_step_completed',
-            data: completedEvent as unknown as Agents.ToolEndEvent,
+            event: StepEvents.ON_RUN_STEP_COMPLETED,
+            data: completedEvent as { result: Agents.ToolEndEvent },
          },
          submission,
        );
@ -710,8 +734,8 @@ describe('useStepHandler', () => {
      act(() => {
        result.current.stepHandler(
          {
-            event: 'on_run_step_completed',
-            data: completedEvent as unknown as Agents.ToolEndEvent,
+            event: StepEvents.ON_RUN_STEP_COMPLETED,
+            data: completedEvent as { result: Agents.ToolEndEvent },
          },
          submission,
        );
@ -735,7 +759,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      act(() => {
@ -746,7 +770,7 @@ describe('useStepHandler', () => {

      act(() => {
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta('step-1', 'Test') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta('step-1', 'Test') },
          submission,
        );
      });
@ -772,12 +796,12 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      act(() => {
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta('step-1', ' more') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta('step-1', ' more') },
          submission,
        );
      });
@ -824,7 +848,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockAnnouncePolite).toHaveBeenCalledWith({ message: 'composing', isStatus: true });
@ -842,7 +866,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockAnnouncePolite).not.toHaveBeenCalled();
@ -872,7 +896,7 @@ describe('useStepHandler', () => {
      });

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -891,15 +915,15 @@ describe('useStepHandler', () => {

      act(() => {
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta(stepId, 'First ') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta(stepId, 'First ') },
          submission,
        );
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta(stepId, 'Second ') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta(stepId, 'Second ') },
          submission,
        );
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta(stepId, 'Third') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta(stepId, 'Third') },
          submission,
        );
      });
@ -909,7 +933,7 @@ describe('useStepHandler', () => {
      const runStep = createRunStep({ id: stepId });

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -931,11 +955,14 @@ describe('useStepHandler', () => {

      act(() => {
        result.current.stepHandler(
-          { event: 'on_reasoning_delta', data: createReasoningDelta(stepId, 'Thinking...') },
+          {
+            event: StepEvents.ON_REASONING_DELTA,
+            data: createReasoningDelta(stepId, 'Thinking...'),
+          },
          submission,
        );
        result.current.stepHandler(
-          { event: 'on_message_delta', data: createMessageDelta(stepId, 'Response') },
+          { event: StepEvents.ON_MESSAGE_DELTA, data: createMessageDelta(stepId, 'Response') },
          submission,
        );
      });
@ -945,7 +972,7 @@ describe('useStepHandler', () => {
      const runStep = createRunStep({ id: stepId });

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -971,7 +998,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      const textDelta: Agents.MessageDeltaEvent = {
@ -980,7 +1007,10 @@ describe('useStepHandler', () => {
      };

      act(() => {
-        result.current.stepHandler({ event: 'on_message_delta', data: textDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_MESSAGE_DELTA, data: textDelta },
+          submission,
+        );
      });

      expect(consoleSpy).toHaveBeenCalledWith(
@ -1004,7 +1034,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -1019,7 +1049,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -1035,7 +1065,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      const messageDelta: Agents.MessageDeltaEvent = {
@ -1049,7 +1079,10 @@ describe('useStepHandler', () => {
      };

      act(() => {
-        result.current.stepHandler({ event: 'on_message_delta', data: messageDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_MESSAGE_DELTA, data: messageDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).toHaveBeenCalled();
@ -1065,7 +1098,7 @@ describe('useStepHandler', () => {
      const submission = createSubmission();

      act(() => {
-        result.current.stepHandler({ event: 'on_run_step', data: runStep }, submission);
+        result.current.stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, submission);
      });

      mockSetMessages.mockClear();
@ -1076,7 +1109,10 @@ describe('useStepHandler', () => {
      };

      act(() => {
-        result.current.stepHandler({ event: 'on_message_delta', data: messageDelta }, submission);
+        result.current.stepHandler(
+          { event: StepEvents.ON_MESSAGE_DELTA, data: messageDelta },
+          submission,
+        );
      });

      expect(mockSetMessages).not.toHaveBeenCalled();
--- a/client/src/hooks/SSE/useResumableSSE.ts
+++ b/client/src/hooks/SSE/useResumableSSE.ts
@ -8,6 +8,7 @@ import {
  Constants,
  QueryKeys,
  ErrorTypes,
+  StepEvents,
  apiBaseUrl,
  createPayload,
  ViolationTypes,
@ -234,7 +235,7 @@ export default function useResumableSSE(
            // Replay run steps
            if (data.resumeState?.runSteps) {
              for (const runStep of data.resumeState.runSteps) {
-                stepHandler({ event: 'on_run_step', data: runStep }, {
+                stepHandler({ event: StepEvents.ON_RUN_STEP, data: runStep }, {
                  ...currentSubmission,
                  userMessage,
                } as EventSubmission);
--- a/client/src/hooks/SSE/useStepHandler.ts
+++ b/client/src/hooks/SSE/useStepHandler.ts
@ -2,6 +2,7 @@ import { useCallback, useRef } from 'react';
 import {
  Constants,
  StepTypes,
+  StepEvents,
  ContentTypes,
  ToolCallTypes,
  getNonEmptyValue,
@ -13,6 +14,7 @@ import type {
  ContentMetadata,
  EventSubmission,
  TMessageContentParts,
+  SummaryContentPart,
 } from 'librechat-data-provider';
 import type { SetterOrUpdater } from 'recoil';
 import type { AnnounceOptions } from '~/common';
@ -27,20 +29,16 @@ type TUseStepHandler = {
  lastAnnouncementTimeRef: React.MutableRefObject<number>;
 };

-type TStepEvent = {
-  event: string;
-  data:
-    | Agents.MessageDeltaEvent
-    | Agents.ReasoningDeltaEvent
-    | Agents.RunStepDeltaEvent
-    | Agents.AgentUpdate
-    | Agents.RunStep
-    | Agents.ToolEndEvent
-    | {
-        runId?: string;
-        message: string;
-      };
-};
+type TStepEvent =
+  | { event: StepEvents.ON_RUN_STEP; data: Agents.RunStep }
+  | { event: StepEvents.ON_AGENT_UPDATE; data: Agents.AgentUpdate }
+  | { event: StepEvents.ON_MESSAGE_DELTA; data: Agents.MessageDeltaEvent }
+  | { event: StepEvents.ON_REASONING_DELTA; data: Agents.ReasoningDeltaEvent }
+  | { event: StepEvents.ON_RUN_STEP_DELTA; data: Agents.RunStepDeltaEvent }
+  | { event: StepEvents.ON_RUN_STEP_COMPLETED; data: { result: Agents.ToolEndEvent } }
+  | { event: StepEvents.ON_SUMMARIZE_START; data: Agents.SummarizeStartEvent }
+  | { event: StepEvents.ON_SUMMARIZE_DELTA; data: Agents.SummarizeDeltaEvent }
+  | { event: StepEvents.ON_SUMMARIZE_COMPLETE; data: Agents.SummarizeCompleteEvent };

 type MessageDeltaUpdate = { type: ContentTypes.TEXT; text: string; tool_call_ids?: string[] };

@ -52,6 +50,7 @@ type AllContentTypes =
  | ContentTypes.TOOL_CALL
  | ContentTypes.IMAGE_FILE
  | ContentTypes.IMAGE_URL
+  | ContentTypes.SUMMARY
  | ContentTypes.ERROR;

 export default function useStepHandler({
@ -138,7 +137,7 @@ export default function useStepHandler({
        text: (currentContent.text || '') + contentPart.text,
      };

-      if (contentPart.tool_call_ids != null) {
+      if ('tool_call_ids' in contentPart && contentPart.tool_call_ids != null) {
        update.tool_call_ids = contentPart.tool_call_ids;
      }
      updatedContent[index] = update;
@ -173,6 +172,13 @@ export default function useStepHandler({
      updatedContent[index] = {
        ...currentContent,
      };
+    } else if (contentType === ContentTypes.SUMMARY) {
+      const currentSummary = updatedContent[index] as SummaryContentPart | undefined;
+      const incoming = contentPart as SummaryContentPart;
+      updatedContent[index] = {
+        ...incoming,
+        content: [...(currentSummary?.content ?? []), ...(incoming.content ?? [])],
+      };
    } else if (contentType === ContentTypes.TOOL_CALL && 'tool_call' in contentPart) {
      const existingContent = updatedContent[index] as Agents.ToolCallContent | undefined;
      const existingToolCall = existingContent?.tool_call;
@ -243,7 +249,7 @@ export default function useStepHandler({
  };

  const stepHandler = useCallback(
-    ({ event, data }: TStepEvent, submission: EventSubmission) => {
+    (stepEvent: TStepEvent, submission: EventSubmission) => {
      const messages = getMessages() || [];
      const { userMessage } = submission;
      let parentMessageId = userMessage.messageId;
@ -260,8 +266,8 @@ export default function useStepHandler({
        initialContent = submission?.initialResponse?.content ?? initialContent;
      }

-      if (event === 'on_run_step') {
-        const runStep = data as Agents.RunStep;
+      if (stepEvent.event === StepEvents.ON_RUN_STEP) {
+        const runStep = stepEvent.data;
        let responseMessageId = runStep.runId ?? '';
        if (responseMessageId === Constants.USE_PRELIM_RESPONSE_MESSAGE_ID) {
          responseMessageId = submission?.initialResponse?.messageId ?? '';
@ -355,15 +361,38 @@ export default function useStepHandler({
          setMessages(updatedMessages);
        }

+        if (runStep.summary != null) {
+          const summaryPart: SummaryContentPart = {
+            type: ContentTypes.SUMMARY,
+            content: [],
+            summarizing: true,
+            model: runStep.summary.model,
+            provider: runStep.summary.provider,
+          };
+
+          let updatedResponse = { ...(messageMap.current.get(responseMessageId) ?? response) };
+          updatedResponse = updateContent(
+            updatedResponse,
+            contentIndex,
+            summaryPart,
+            false,
+            getStepMetadata(runStep),
+          );
+
+          messageMap.current.set(responseMessageId, updatedResponse);
+          const currentMessages = getMessages() || [];
+          setMessages([...currentMessages.slice(0, -1), updatedResponse]);
+        }
+
        const bufferedDeltas = pendingDeltaBuffer.current.get(runStep.id);
        if (bufferedDeltas && bufferedDeltas.length > 0) {
          pendingDeltaBuffer.current.delete(runStep.id);
          for (const bufferedDelta of bufferedDeltas) {
-            stepHandler({ event: bufferedDelta.event, data: bufferedDelta.data }, submission);
+            stepHandler(bufferedDelta, submission);
          }
        }
-      } else if (event === 'on_agent_update') {
-        const { agent_update } = data as Agents.AgentUpdate;
+      } else if (stepEvent.event === StepEvents.ON_AGENT_UPDATE) {
+        const { agent_update } = stepEvent.data;
        let responseMessageId = agent_update.runId || '';
        if (responseMessageId === Constants.USE_PRELIM_RESPONSE_MESSAGE_ID) {
          responseMessageId = submission?.initialResponse?.messageId ?? '';
@ -385,7 +414,7 @@ export default function useStepHandler({
          const updatedResponse = updateContent(
            response,
            currentIndex,
-            data,
+            stepEvent.data,
            false,
            agentUpdateMeta,
          );
@ -393,8 +422,8 @@ export default function useStepHandler({
          const currentMessages = getMessages() || [];
          setMessages([...currentMessages.slice(0, -1), updatedResponse]);
        }
-      } else if (event === 'on_message_delta') {
-        const messageDelta = data as Agents.MessageDeltaEvent;
+      } else if (stepEvent.event === StepEvents.ON_MESSAGE_DELTA) {
+        const messageDelta = stepEvent.data;
        const runStep = stepMap.current.get(messageDelta.id);
        let responseMessageId = runStep?.runId ?? '';
        if (responseMessageId === Constants.USE_PRELIM_RESPONSE_MESSAGE_ID) {
@ -404,7 +433,7 @@ export default function useStepHandler({

        if (!runStep || !responseMessageId) {
          const buffer = pendingDeltaBuffer.current.get(messageDelta.id) ?? [];
-          buffer.push({ event: 'on_message_delta', data: messageDelta });
+          buffer.push({ event: StepEvents.ON_MESSAGE_DELTA, data: messageDelta });
          pendingDeltaBuffer.current.set(messageDelta.id, buffer);
          return;
        }
@ -436,8 +465,8 @@ export default function useStepHandler({
          const currentMessages = getMessages() || [];
          setMessages([...currentMessages.slice(0, -1), updatedResponse]);
        }
-      } else if (event === 'on_reasoning_delta') {
-        const reasoningDelta = data as Agents.ReasoningDeltaEvent;
+      } else if (stepEvent.event === StepEvents.ON_REASONING_DELTA) {
+        const reasoningDelta = stepEvent.data;
        const runStep = stepMap.current.get(reasoningDelta.id);
        let responseMessageId = runStep?.runId ?? '';
        if (responseMessageId === Constants.USE_PRELIM_RESPONSE_MESSAGE_ID) {
@ -447,7 +476,7 @@ export default function useStepHandler({

        if (!runStep || !responseMessageId) {
          const buffer = pendingDeltaBuffer.current.get(reasoningDelta.id) ?? [];
-          buffer.push({ event: 'on_reasoning_delta', data: reasoningDelta });
+          buffer.push({ event: StepEvents.ON_REASONING_DELTA, data: reasoningDelta });
          pendingDeltaBuffer.current.set(reasoningDelta.id, buffer);
          return;
        }
@ -479,8 +508,8 @@ export default function useStepHandler({
          const currentMessages = getMessages() || [];
          setMessages([...currentMessages.slice(0, -1), updatedResponse]);
        }
-      } else if (event === 'on_run_step_delta') {
-        const runStepDelta = data as Agents.RunStepDeltaEvent;
+      } else if (stepEvent.event === StepEvents.ON_RUN_STEP_DELTA) {
+        const runStepDelta = stepEvent.data;
        const runStep = stepMap.current.get(runStepDelta.id);
        let responseMessageId = runStep?.runId ?? '';
        if (responseMessageId === Constants.USE_PRELIM_RESPONSE_MESSAGE_ID) {
@ -490,7 +519,7 @@ export default function useStepHandler({

        if (!runStep || !responseMessageId) {
          const buffer = pendingDeltaBuffer.current.get(runStepDelta.id) ?? [];
-          buffer.push({ event: 'on_run_step_delta', data: runStepDelta });
+          buffer.push({ event: StepEvents.ON_RUN_STEP_DELTA, data: runStepDelta });
          pendingDeltaBuffer.current.set(runStepDelta.id, buffer);
          return;
        }
@ -538,8 +567,8 @@ export default function useStepHandler({

          setMessages(updatedMessages);
        }
-      } else if (event === 'on_run_step_completed') {
-        const { result } = data as unknown as { result: Agents.ToolEndEvent };
+      } else if (stepEvent.event === StepEvents.ON_RUN_STEP_COMPLETED) {
+        const { result } = stepEvent.data;

        const { id: stepId } = result;

@ -581,6 +610,95 @@ export default function useStepHandler({

          setMessages(updatedMessages);
        }
+      } else if (stepEvent.event === StepEvents.ON_SUMMARIZE_START) {
+        announcePolite({ message: 'summarize_started', isStatus: true });
+      } else if (stepEvent.event === StepEvents.ON_SUMMARIZE_DELTA) {
+        const deltaData = stepEvent.data;
+        const runStep = stepMap.current.get(deltaData.id);
+        let responseMessageId = runStep?.runId ?? '';
+        if (responseMessageId === Constants.USE_PRELIM_RESPONSE_MESSAGE_ID) {
+          responseMessageId = submission?.initialResponse?.messageId ?? '';
+          parentMessageId = submission?.initialResponse?.parentMessageId ?? '';
+        }
+
+        if (!runStep || !responseMessageId) {
+          const buffer = pendingDeltaBuffer.current.get(deltaData.id) ?? [];
+          buffer.push({ event: StepEvents.ON_SUMMARIZE_DELTA, data: deltaData });
+          pendingDeltaBuffer.current.set(deltaData.id, buffer);
+          return;
+        }
+
+        const response = messageMap.current.get(responseMessageId);
+        if (response) {
+          const contentPart: SummaryContentPart = {
+            ...deltaData.delta.summary,
+            summarizing: true,
+          };
+
+          const contentIndex = runStep.index + initialContent.length;
+          const updatedResponse = updateContent(
+            response,
+            contentIndex,
+            contentPart,
+            false,
+            getStepMetadata(runStep),
+          );
+          messageMap.current.set(responseMessageId, updatedResponse);
+          const currentMessages = getMessages() || [];
+          setMessages([...currentMessages.slice(0, -1), updatedResponse]);
+        }
+      } else if (stepEvent.event === StepEvents.ON_SUMMARIZE_COMPLETE) {
+        const completeData = stepEvent.data;
+        const completeRunStep = stepMap.current.get(completeData.id);
+        let completeMessageId = completeRunStep?.runId ?? '';
+        if (completeMessageId === Constants.USE_PRELIM_RESPONSE_MESSAGE_ID) {
+          completeMessageId = submission?.initialResponse?.messageId ?? '';
+        }
+
+        const targetMessage = messageMap.current.get(completeMessageId);
+        if (!targetMessage || !Array.isArray(targetMessage.content)) {
+          return;
+        }
+
+        const currentMessages = getMessages() || [];
+        const targetIndex = currentMessages.findIndex((m) => m.messageId === completeMessageId);
+
+        if (completeData.error) {
+          announcePolite({ message: 'summarize_failed', isStatus: true });
+          const filtered = targetMessage.content.filter(
+            (part) =>
+              part?.type !== ContentTypes.SUMMARY || !(part as SummaryContentPart).summarizing,
+          );
+          if (filtered.length !== targetMessage.content.length) {
+            const cleaned = { ...targetMessage, content: filtered };
+            messageMap.current.set(completeMessageId, cleaned);
+            if (targetIndex >= 0) {
+              const updated = [...currentMessages];
+              updated[targetIndex] = cleaned;
+              setMessages(updated);
+            }
+          }
+        } else {
+          announcePolite({ message: 'summarize_completed', isStatus: true });
+          let didFinalize = false;
+          const updatedContent = targetMessage.content.map((part) => {
+            if (part?.type === ContentTypes.SUMMARY && (part as SummaryContentPart).summarizing) {
+              if (!completeData.summary) {
+                return part;
+              }
+              didFinalize = true;
+              return { ...completeData.summary, summarizing: false } as SummaryContentPart;
+            }
+            return part;
+          });
+          if (didFinalize && targetIndex >= 0) {
+            const finalized = { ...targetMessage, content: updatedContent };
+            messageMap.current.set(completeMessageId, finalized);
+            const updated = [...currentMessages];
+            updated[targetIndex] = finalized;
+            setMessages(updated);
+          }
+        }
      }

      return () => {
--- a/client/src/locales/en/translation.json
+++ b/client/src/locales/en/translation.json
@ -4,6 +4,9 @@
  "com_a11y_ai_composing": "The AI is still composing.",
  "com_a11y_end": "The AI has finished their reply.",
  "com_a11y_selected": "selected",
+  "com_a11y_summarize_completed": "Context summarized.",
+  "com_a11y_summarize_failed": "Summarization failed, continuing with available context.",
+  "com_a11y_summarize_started": "Summarizing context.",
  "com_a11y_start": "The AI has started their reply.",
  "com_agents_agent_card_label": "{{name}} agent. {{description}}",
  "com_agents_all": "All Agents",
@ -824,6 +827,7 @@
  "com_ui_code": "Code",
  "com_ui_collapse": "Collapse",
  "com_ui_collapse_chat": "Collapse Chat",
+  "com_ui_collapse_summary": "Collapse Summary",
  "com_ui_collapse_thoughts": "Collapse Thoughts",
  "com_ui_command_placeholder": "Optional: Enter a command for the prompt or name will be used",
  "com_ui_command_usage_placeholder": "Select a Prompt by command or name",
@ -846,6 +850,7 @@
  "com_ui_conversation": "conversation",
  "com_ui_conversation_label": "{{title}} conversation",
  "com_ui_conversation_not_found": "Conversation not found",
+  "com_ui_conversation_summarized": "Conversation summarized",
  "com_ui_conversations": "conversations",
  "com_ui_convo_archived": "Conversation archived",
  "com_ui_convo_delete_error": "Failed to delete conversation",
@ -856,6 +861,7 @@
  "com_ui_copy_code": "Copy code",
  "com_ui_copy_link": "Copy link",
  "com_ui_copy_stack_trace": "Copy stack trace",
+  "com_ui_copy_summary": "Copy summary to clipboard",
  "com_ui_copy_thoughts_to_clipboard": "Copy thoughts to clipboard",
  "com_ui_copy_to_clipboard": "Copy to clipboard",
  "com_ui_copy_url_to_clipboard": "Copy URL to clipboard",
@ -977,6 +983,7 @@
  "com_ui_examples": "Examples",
  "com_ui_expand": "Expand",
  "com_ui_expand_chat": "Expand Chat",
+  "com_ui_expand_summary": "Expand Summary",
  "com_ui_expand_thoughts": "Expand Thoughts",
  "com_ui_export_convo_modal": "Export Conversation Modal",
  "com_ui_feedback_more": "More...",
@ -1408,6 +1415,7 @@
  "com_ui_storage": "Storage",
  "com_ui_storage_filter_sort": "Filter and Sort by Storage",
  "com_ui_submit": "Submit",
+  "com_ui_summarizing": "Summarizing...",
  "com_ui_support_contact": "Support Contact",
  "com_ui_support_contact_email": "Email",
  "com_ui_support_contact_email_invalid": "Please enter a valid email address",
--- a/packages/api/src/agents/tests/initialize.test.ts
+++ b/packages/api/src/agents/tests/initialize.test.ts
@ -190,7 +190,7 @@ describe('initializeAgent — maxContextTokens', () => {
      db,
    );

-    const expected = Math.round((modelDefault - maxOutputTokens) * 0.9);
+    const expected = Math.round((modelDefault - maxOutputTokens) * 0.95);
    expect(result.maxContextTokens).toBe(expected);
  });

@ -222,7 +222,7 @@ describe('initializeAgent — maxContextTokens', () => {
    // optionalChainWithEmptyCheck(0, 200000, 18000) returns 0 (not null/undefined),
    // then Number(0) || 18000 = 18000 (the fallback default).
    expect(result.maxContextTokens).not.toBe(0);
-    const expected = Math.round((18000 - maxOutputTokens) * 0.9);
+    const expected = Math.round((18000 - maxOutputTokens) * 0.95);
    expect(result.maxContextTokens).toBe(expected);
  });

@ -278,7 +278,59 @@ describe('initializeAgent — maxContextTokens', () => {
      db,
    );

-    // Should NOT be overridden to Math.round((128000 - 4096) * 0.9) = 111,514
+    // Should NOT be overridden to Math.round((128000 - 4096) * 0.95) = 117,709
    expect(result.maxContextTokens).toBe(userValue);
  });
+
+  it('sets baseContextTokens to agentMaxContextNum minus maxOutputTokensNum', async () => {
+    const modelDefault = 200000;
+    const maxOutputTokens = 4096;
+    const { agent, req, res, loadTools, db } = createMocks({
+      maxContextTokens: undefined,
+      modelDefault,
+      maxOutputTokens,
+    });
+
+    const result = await initializeAgent(
+      {
+        req,
+        res,
+        agent,
+        loadTools,
+        endpointOption: { endpoint: EModelEndpoint.agents },
+        allowedProviders: new Set([Providers.OPENAI]),
+        isInitialAgent: true,
+      },
+      db,
+    );
+
+    expect(result.baseContextTokens).toBe(modelDefault - maxOutputTokens);
+  });
+
+  it('clamps maxContextTokens to at least 1024 for tiny models', async () => {
+    const modelDefault = 1100;
+    const maxOutputTokens = 1050;
+    const { agent, req, res, loadTools, db } = createMocks({
+      maxContextTokens: undefined,
+      modelDefault,
+      maxOutputTokens,
+    });
+
+    const result = await initializeAgent(
+      {
+        req,
+        res,
+        agent,
+        loadTools,
+        endpointOption: { endpoint: EModelEndpoint.agents },
+        allowedProviders: new Set([Providers.OPENAI]),
+        isInitialAgent: true,
+      },
+      db,
+    );
+
+    // baseContextTokens = 1100 - 1050 = 50, formula would give ~47.5 rounded
+    // but Math.max(1024, ...) clamps it
+    expect(result.maxContextTokens).toBe(1024);
+  });
 });
--- a/packages/api/src/agents/tests/run-summarization.test.ts
+++ b/packages/api/src/agents/tests/run-summarization.test.ts
@ -0,0 +1,296 @@
+import type { SummarizationConfig } from 'librechat-data-provider';
+import { createRun } from '~/agents/run';
+
+// Mock winston logger
+jest.mock('winston', () => ({
+  createLogger: jest.fn(() => ({
+    debug: jest.fn(),
+    warn: jest.fn(),
+    error: jest.fn(),
+    info: jest.fn(),
+  })),
+  format: { combine: jest.fn(), colorize: jest.fn(), simple: jest.fn() },
+  transports: { Console: jest.fn() },
+}));
+
+// Mock env utilities so header resolution doesn't fail
+jest.mock('~/utils/env', () => ({
+  resolveHeaders: jest.fn((opts: { headers: unknown }) => opts?.headers ?? {}),
+  createSafeUser: jest.fn(() => ({})),
+}));
+
+// Mock Run.create to capture the graphConfig it receives
+jest.mock('@librechat/agents', () => {
+  const actual = jest.requireActual('@librechat/agents');
+  return {
+    ...actual,
+    Run: {
+      create: jest.fn().mockResolvedValue({
+        processStream: jest.fn().mockResolvedValue(undefined),
+      }),
+    },
+  };
+});
+
+import { Run } from '@librechat/agents';
+
+/** Minimal RunAgent factory */
+function makeAgent(
+  overrides?: Record<string, unknown>,
+): Record<string, unknown> & { id: string; provider: string; model: string } {
+  return {
+    id: 'agent_1',
+    provider: 'openAI',
+    endpoint: 'openAI',
+    model: 'gpt-4o',
+    tools: [],
+    model_parameters: { model: 'gpt-4o' },
+    maxContextTokens: 100_000,
+    toolContextMap: {},
+    ...overrides,
+  };
+}
+
+/** Helper: call createRun and return the captured agentInputs array */
+async function callAndCapture(
+  opts: {
+    agents?: ReturnType<typeof makeAgent>[];
+    summarizationConfig?: SummarizationConfig;
+    initialSummary?: { text: string; tokenCount: number };
+  } = {},
+) {
+  const agents = opts.agents ?? [makeAgent()];
+  const signal = new AbortController().signal;
+
+  await createRun({
+    agents: agents as never,
+    signal,
+    summarizationConfig: opts.summarizationConfig,
+    initialSummary: opts.initialSummary,
+    streaming: true,
+    streamUsage: true,
+  });
+
+  const createMock = Run.create as jest.Mock;
+  expect(createMock).toHaveBeenCalledTimes(1);
+  const callArgs = createMock.mock.calls[0][0];
+  return callArgs.graphConfig.agents as Array<Record<string, unknown>>;
+}
+
+beforeEach(() => {
+  jest.clearAllMocks();
+});
+
+// ---------------------------------------------------------------------------
+// Suite 1: reserveRatio
+// ---------------------------------------------------------------------------
+describe('reserveRatio', () => {
+  it('applies ratio from config using baseContextTokens, capped at maxContextTokens', async () => {
+    const agents = await callAndCapture({
+      agents: [makeAgent({ baseContextTokens: 200_000, maxContextTokens: 200_000 })],
+      summarizationConfig: { reserveRatio: 0.03, provider: 'anthropic', model: 'claude' },
+    });
+    // Math.round(200000 * 0.97) = 194000, min(200000, 194000) = 194000
+    expect(agents[0].maxContextTokens).toBe(194_000);
+  });
+
+  it('never exceeds user-configured maxContextTokens even when ratio computes higher', async () => {
+    const agents = await callAndCapture({
+      agents: [makeAgent({ baseContextTokens: 200_000, maxContextTokens: 50_000 })],
+      summarizationConfig: { reserveRatio: 0.03, provider: 'anthropic', model: 'claude' },
+    });
+    // Math.round(200000 * 0.97) = 194000, but min(50000, 194000) = 50000
+    expect(agents[0].maxContextTokens).toBe(50_000);
+  });
+
+  it('falls back to maxContextTokens when ratio is not set', async () => {
+    const agents = await callAndCapture({
+      agents: [makeAgent({ maxContextTokens: 100_000, baseContextTokens: 200_000 })],
+      summarizationConfig: { provider: 'anthropic', model: 'claude' },
+    });
+    expect(agents[0].maxContextTokens).toBe(100_000);
+  });
+
+  it('falls back to maxContextTokens when ratio is 0', async () => {
+    const agents = await callAndCapture({
+      agents: [makeAgent({ maxContextTokens: 100_000, baseContextTokens: 200_000 })],
+      summarizationConfig: { reserveRatio: 0, provider: 'anthropic', model: 'claude' },
+    });
+    expect(agents[0].maxContextTokens).toBe(100_000);
+  });
+
+  it('falls back to maxContextTokens when ratio is 1', async () => {
+    const agents = await callAndCapture({
+      agents: [makeAgent({ maxContextTokens: 100_000, baseContextTokens: 200_000 })],
+      summarizationConfig: { reserveRatio: 1, provider: 'anthropic', model: 'claude' },
+    });
+    expect(agents[0].maxContextTokens).toBe(100_000);
+  });
+
+  it('falls back to maxContextTokens when baseContextTokens is undefined', async () => {
+    const agents = await callAndCapture({
+      agents: [makeAgent({ maxContextTokens: 100_000 })],
+      summarizationConfig: { reserveRatio: 0.05, provider: 'anthropic', model: 'claude' },
+    });
+    expect(agents[0].maxContextTokens).toBe(100_000);
+  });
+
+  it('clamps to 1024 minimum but still capped at maxContextTokens', async () => {
+    const agents = await callAndCapture({
+      agents: [makeAgent({ baseContextTokens: 500, maxContextTokens: 2000 })],
+      summarizationConfig: { reserveRatio: 0.99, provider: 'anthropic', model: 'claude' },
+    });
+    // Math.round(500 * 0.01) = 5 → clamped to 1024, min(2000, 1024) = 1024
+    expect(agents[0].maxContextTokens).toBe(1024);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Suite 2: maxSummaryTokens passthrough
+// ---------------------------------------------------------------------------
+describe('maxSummaryTokens passthrough', () => {
+  it('forwards global maxSummaryTokens value', async () => {
+    const agents = await callAndCapture({
+      summarizationConfig: {
+        provider: 'anthropic',
+        model: 'claude',
+        maxSummaryTokens: 4096,
+      },
+    });
+    const config = agents[0].summarizationConfig as Record<string, unknown>;
+    expect(config.maxSummaryTokens).toBe(4096);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Suite 3: summarizationEnabled resolution
+// ---------------------------------------------------------------------------
+describe('summarizationEnabled resolution', () => {
+  it('true with provider + model + enabled', async () => {
+    const agents = await callAndCapture({
+      summarizationConfig: {
+        enabled: true,
+        provider: 'anthropic',
+        model: 'claude-3-haiku',
+      },
+    });
+    expect(agents[0].summarizationEnabled).toBe(true);
+  });
+
+  it('false when provider is empty string', async () => {
+    const agents = await callAndCapture({
+      summarizationConfig: {
+        enabled: true,
+        provider: '',
+        model: 'claude-3-haiku',
+      },
+    });
+    expect(agents[0].summarizationEnabled).toBe(false);
+  });
+
+  it('false when enabled is explicitly false', async () => {
+    const agents = await callAndCapture({
+      summarizationConfig: {
+        enabled: false,
+        provider: 'anthropic',
+        model: 'claude-3-haiku',
+      },
+    });
+    expect(agents[0].summarizationEnabled).toBe(false);
+  });
+
+  it('true with self-summarize default when summarizationConfig is undefined', async () => {
+    const agents = await callAndCapture({
+      summarizationConfig: undefined,
+    });
+    expect(agents[0].summarizationEnabled).toBe(true);
+    const config = agents[0].summarizationConfig as Record<string, unknown>;
+    expect(config.provider).toBe('openAI');
+    expect(config.model).toBe('gpt-4o');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Suite 4: summarizationConfig field passthrough
+// ---------------------------------------------------------------------------
+describe('summarizationConfig field passthrough', () => {
+  it('all fields pass through to agentInputs', async () => {
+    const agents = await callAndCapture({
+      summarizationConfig: {
+        enabled: true,
+        trigger: { type: 'token_count', value: 8000 },
+        provider: 'anthropic',
+        model: 'claude-3-haiku',
+        parameters: { temperature: 0.2 },
+        prompt: 'Summarize this conversation',
+        updatePrompt: 'Update the existing summary with new messages',
+        reserveRatio: 0.1,
+        maxSummaryTokens: 4096,
+      },
+    });
+    const config = agents[0].summarizationConfig as Record<string, unknown>;
+    expect(config).toBeDefined();
+    expect(config.enabled).toBe(true);
+    expect(config.trigger).toEqual({ type: 'token_count', value: 8000 });
+    expect(config.provider).toBe('anthropic');
+    expect(config.model).toBe('claude-3-haiku');
+    expect(config.parameters).toEqual({ temperature: 0.2 });
+    expect(config.prompt).toBe('Summarize this conversation');
+    expect(config.updatePrompt).toBe('Update the existing summary with new messages');
+    expect(config.reserveRatio).toBe(0.1);
+    expect(config.maxSummaryTokens).toBe(4096);
+  });
+
+  it('uses self-summarize default when no config provided', async () => {
+    const agents = await callAndCapture({
+      summarizationConfig: undefined,
+    });
+    const config = agents[0].summarizationConfig as Record<string, unknown>;
+    expect(config).toBeDefined();
+    expect(config.enabled).toBe(true);
+    expect(config.provider).toBe('openAI');
+    expect(config.model).toBe('gpt-4o');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Suite 5: Multi-agent + per-agent overrides
+// ---------------------------------------------------------------------------
+describe('multi-agent + per-agent overrides', () => {
+  it('different agents get different effectiveMaxContextTokens', async () => {
+    const agents = await callAndCapture({
+      agents: [
+        makeAgent({ id: 'agent_1', baseContextTokens: 200_000, maxContextTokens: 100_000 }),
+        makeAgent({ id: 'agent_2', baseContextTokens: 100_000, maxContextTokens: 50_000 }),
+      ],
+      summarizationConfig: {
+        reserveRatio: 0.1,
+        provider: 'anthropic',
+        model: 'claude',
+      },
+    });
+    // agent_1: Math.round(200000 * 0.9) = 180000, but capped at user's maxContextTokens (100000)
+    expect(agents[0].maxContextTokens).toBe(100_000);
+    // agent_2: Math.round(100000 * 0.9) = 90000, but capped at user's maxContextTokens (50000)
+    expect(agents[1].maxContextTokens).toBe(50_000);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Suite 6: initialSummary passthrough
+// ---------------------------------------------------------------------------
+describe('initialSummary passthrough', () => {
+  it('forwarded to agent inputs', async () => {
+    const summary = { text: 'Previous conversation summary', tokenCount: 500 };
+    const agents = await callAndCapture({
+      initialSummary: summary,
+      summarizationConfig: { provider: 'anthropic', model: 'claude' },
+    });
+    expect(agents[0].initialSummary).toEqual(summary);
+  });
+
+  it('undefined when not provided', async () => {
+    const agents = await callAndCapture({});
+    expect(agents[0].initialSummary).toBeUndefined();
+  });
+});
--- a/packages/api/src/agents/tests/summarization.e2e.test.ts
+++ b/packages/api/src/agents/tests/summarization.e2e.test.ts
@ -0,0 +1,594 @@
+/**
+ * E2E Backend Integration Tests for Summarization
+ *
+ * Exercises the FULL LibreChat -> agents pipeline:
+ *   LibreChat's createRun (@librechat/api)
+ *     -> agents package Run.create (@librechat/agents)
+ *     -> graph execution -> summarization node -> events
+ *
+ * Uses real AI providers, real formatAgentMessages, real token accounting.
+ * Tracks summaries both mid-run and between runs.
+ *
+ * Run from packages/api:
+ *   npx jest summarization.e2e --no-coverage --testTimeout=180000
+ *
+ * Requires real API keys in the environment (ANTHROPIC_API_KEY, OPENAI_API_KEY).
+ */
+import {
+  Providers,
+  Calculator,
+  GraphEvents,
+  ToolEndHandler,
+  ModelEndHandler,
+  createTokenCounter,
+  formatAgentMessages,
+  ChatModelStreamHandler,
+  createContentAggregator,
+} from '@librechat/agents';
+import type {
+  SummarizeCompleteEvent,
+  MessageContentComplex,
+  SummaryContentBlock,
+  SummarizeStartEvent,
+  TokenCounter,
+  EventHandler,
+} from '@librechat/agents';
+import { hydrateMissingIndexTokenCounts } from '~/utils';
+import { createRun } from '~/agents';
+
+// @librechat/api opens a Redis connection on import; force exit after all tests.
+afterAll(() => {
+  setTimeout(() => process.exit(0), 1000);
+});
+
+// ---------------------------------------------------------------------------
+// Shared test infrastructure
+// ---------------------------------------------------------------------------
+
+interface Spies {
+  onMessageDelta: jest.Mock;
+  onRunStep: jest.Mock;
+  onSummarizeStart: jest.Mock;
+  onSummarizeDelta: jest.Mock;
+  onSummarizeComplete: jest.Mock;
+}
+
+type PayloadMessage = {
+  role: string;
+  content: string | Array<Record<string, unknown>>;
+};
+
+function getSummaryText(summary: SummaryContentBlock): string {
+  if (Array.isArray(summary.content)) {
+    return summary.content
+      .map((b: MessageContentComplex) => ('text' in b ? (b as { text: string }).text : ''))
+      .join('');
+  }
+  return '';
+}
+
+function createSpies(): Spies {
+  return {
+    onMessageDelta: jest.fn(),
+    onRunStep: jest.fn(),
+    onSummarizeStart: jest.fn(),
+    onSummarizeDelta: jest.fn(),
+    onSummarizeComplete: jest.fn(),
+  };
+}
+
+function buildHandlers(
+  collectedUsage: ConstructorParameters<typeof ModelEndHandler>[0],
+  aggregateContent: (params: { event: string; data: unknown }) => void,
+  spies: Spies,
+): Record<string, EventHandler> {
+  return {
+    [GraphEvents.TOOL_END]: new ToolEndHandler(),
+    [GraphEvents.CHAT_MODEL_END]: new ModelEndHandler(collectedUsage),
+    [GraphEvents.CHAT_MODEL_STREAM]: new ChatModelStreamHandler(),
+    [GraphEvents.ON_RUN_STEP]: {
+      handle: (event: string, data: unknown) => {
+        spies.onRunStep(event, data);
+        aggregateContent({ event, data });
+      },
+    },
+    [GraphEvents.ON_RUN_STEP_COMPLETED]: {
+      handle: (event: string, data: unknown) => {
+        aggregateContent({ event, data });
+      },
+    },
+    [GraphEvents.ON_RUN_STEP_DELTA]: {
+      handle: (event: string, data: unknown) => {
+        aggregateContent({ event, data });
+      },
+    },
+    [GraphEvents.ON_MESSAGE_DELTA]: {
+      handle: (event: string, data: unknown, metadata?: Record<string, unknown>) => {
+        spies.onMessageDelta(event, data, metadata);
+        aggregateContent({ event, data });
+      },
+    },
+    [GraphEvents.TOOL_START]: {
+      handle: () => {},
+    },
+    [GraphEvents.ON_SUMMARIZE_START]: {
+      handle: (_event: string, data: unknown) => {
+        spies.onSummarizeStart(data);
+      },
+    },
+    [GraphEvents.ON_SUMMARIZE_DELTA]: {
+      handle: (_event: string, data: unknown) => {
+        spies.onSummarizeDelta(data);
+        aggregateContent({ event: GraphEvents.ON_SUMMARIZE_DELTA, data });
+      },
+    },
+    [GraphEvents.ON_SUMMARIZE_COMPLETE]: {
+      handle: (_event: string, data: unknown) => {
+        spies.onSummarizeComplete(data);
+      },
+    },
+  };
+}
+
+function getDefaultModel(provider: string): string {
+  switch (provider) {
+    case Providers.ANTHROPIC:
+      return 'claude-haiku-4-5-20251001';
+    case Providers.OPENAI:
+      return 'gpt-4.1-mini';
+    default:
+      return 'gpt-4.1-mini';
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Turn runner — mirrors AgentClient.chatCompletion() message flow
+// ---------------------------------------------------------------------------
+
+interface RunFullTurnParams {
+  payload: PayloadMessage[];
+  agentProvider: string;
+  summarizationProvider: string;
+  summarizationModel?: string;
+  maxContextTokens: number;
+  instructions: string;
+  spies: Spies;
+  tokenCounter: TokenCounter;
+  model?: string;
+}
+
+async function runFullTurn({
+  payload,
+  agentProvider,
+  summarizationProvider,
+  summarizationModel,
+  maxContextTokens,
+  instructions,
+  spies,
+  tokenCounter,
+  model,
+}: RunFullTurnParams) {
+  const collectedUsage: ConstructorParameters<typeof ModelEndHandler>[0] = [];
+  const { contentParts, aggregateContent } = createContentAggregator();
+
+  const formatted = formatAgentMessages(payload as never, {});
+  const { messages: initialMessages, summary: initialSummary } = formatted;
+  let { indexTokenCountMap } = formatted;
+
+  indexTokenCountMap = hydrateMissingIndexTokenCounts({
+    messages: initialMessages,
+    indexTokenCountMap: indexTokenCountMap as Record<string, number | undefined>,
+    tokenCounter,
+  });
+
+  const abortController = new AbortController();
+  const agent = {
+    id: `test-agent-${agentProvider}`,
+    name: 'Test Agent',
+    provider: agentProvider,
+    instructions,
+    tools: [new Calculator()],
+    maxContextTokens,
+    model_parameters: {
+      model: model || getDefaultModel(agentProvider),
+      streaming: true,
+      streamUsage: true,
+    },
+  };
+
+  const summarizationConfig = {
+    enabled: true,
+    provider: summarizationProvider,
+    model: summarizationModel || getDefaultModel(summarizationProvider),
+    prompt:
+      'You are a summarization assistant. Summarize the following conversation messages concisely, preserving key facts, decisions, and context needed to continue the conversation. Do not include preamble -- output only the summary.',
+  };
+
+  const run = await createRun({
+    agents: [agent] as never,
+    messages: initialMessages,
+    indexTokenCountMap,
+    initialSummary,
+    runId: `e2e-${Date.now()}`,
+    signal: abortController.signal,
+    customHandlers: buildHandlers(collectedUsage, aggregateContent, spies) as never,
+    summarizationConfig,
+    tokenCounter,
+  });
+
+  const streamConfig = {
+    configurable: { thread_id: `e2e-${Date.now()}` },
+    recursionLimit: 100,
+    streamMode: 'values' as const,
+    version: 'v2' as const,
+  };
+  let result: unknown;
+  let processError: Error | undefined;
+  try {
+    result = await run.processStream({ messages: initialMessages }, streamConfig);
+  } catch (err) {
+    processError = err as Error;
+  }
+  const runMessages = run.getRunMessages() || [];
+
+  return {
+    result,
+    processError,
+    runMessages,
+    collectedUsage,
+    contentParts,
+    indexTokenCountMap,
+  };
+}
+
+function getLastContent(runMessages: Array<{ content: string | unknown }>): string {
+  const last = runMessages[runMessages.length - 1];
+  if (!last) {
+    return '';
+  }
+  return typeof last.content === 'string' ? last.content : JSON.stringify(last.content);
+}
+
+// ---------------------------------------------------------------------------
+// Anthropic Tests
+// ---------------------------------------------------------------------------
+
+const hasAnthropic =
+  process.env.ANTHROPIC_API_KEY != null && process.env.ANTHROPIC_API_KEY !== 'test';
+(hasAnthropic ? describe : describe.skip)('Anthropic Summarization E2E (LibreChat)', () => {
+  jest.setTimeout(180_000);
+
+  const instructions =
+    'You are an expert math tutor. You MUST use the calculator tool for ALL computations. Keep answers to 1-2 sentences.';
+
+  test('multi-turn triggers summarization, summary persists across runs', async () => {
+    const spies = createSpies();
+    const tokenCounter = await createTokenCounter();
+    const conversationPayload: PayloadMessage[] = [];
+
+    const addTurn = async (userMsg: string, maxTokens: number) => {
+      conversationPayload.push({ role: 'user', content: userMsg });
+      const result = await runFullTurn({
+        payload: conversationPayload,
+        agentProvider: Providers.ANTHROPIC,
+        summarizationProvider: Providers.ANTHROPIC,
+        summarizationModel: 'claude-haiku-4-5-20251001',
+        maxContextTokens: maxTokens,
+        instructions,
+        spies,
+        tokenCounter,
+      });
+      conversationPayload.push({ role: 'assistant', content: getLastContent(result.runMessages) });
+      return result;
+    };
+
+    await addTurn('What is 12345 * 6789? Use the calculator.', 2000);
+    await addTurn(
+      'Now divide that result by 137. Then multiply by 42. Calculator for each step.',
+      2000,
+    );
+    await addTurn(
+      'Compute step by step: 1) 9876543 - 1234567  2) sqrt of result  3) Add 100. Calculator for each.',
+      1500,
+    );
+    await addTurn('What is 2^20? Calculator. Then list everything we calculated so far.', 800);
+
+    if (spies.onSummarizeStart.mock.calls.length === 0) {
+      await addTurn('Calculate 355 / 113. Calculator.', 600);
+    }
+    if (spies.onSummarizeStart.mock.calls.length === 0) {
+      await addTurn('What is 999 * 999? Calculator.', 400);
+    }
+
+    const startCalls = spies.onSummarizeStart.mock.calls.length;
+    const completeCalls = spies.onSummarizeComplete.mock.calls.length;
+
+    expect(startCalls).toBeGreaterThanOrEqual(1);
+    expect(completeCalls).toBeGreaterThanOrEqual(1);
+
+    const startPayload = spies.onSummarizeStart.mock.calls[0][0] as SummarizeStartEvent;
+    expect(startPayload.agentId).toBeDefined();
+    expect(startPayload.provider).toBeDefined();
+    expect(startPayload.messagesToRefineCount).toBeGreaterThan(0);
+    expect(startPayload.summaryVersion).toBeGreaterThanOrEqual(1);
+
+    const completePayload = spies.onSummarizeComplete.mock.calls[0][0] as SummarizeCompleteEvent;
+    expect(completePayload.summary).toBeDefined();
+    expect(getSummaryText(completePayload.summary!).length).toBeGreaterThan(10);
+    expect(completePayload.summary!.tokenCount).toBeGreaterThan(0);
+    expect(completePayload.summary!.tokenCount!).toBeLessThan(2000);
+    expect(completePayload.summary!.provider).toBeDefined();
+    expect(completePayload.summary!.createdAt).toBeDefined();
+    expect(completePayload.summary!.summaryVersion).toBeGreaterThanOrEqual(1);
+
+    // --- Cross-run: persist summary -> formatAgentMessages -> new run ---
+    const summaryBlock = completePayload.summary!;
+    const crossRunPayload: PayloadMessage[] = [
+      {
+        role: 'assistant',
+        content: [
+          {
+            type: 'summary',
+            content: [{ type: 'text', text: getSummaryText(summaryBlock) }],
+            tokenCount: summaryBlock.tokenCount,
+          },
+        ],
+      },
+      conversationPayload[conversationPayload.length - 2],
+      conversationPayload[conversationPayload.length - 1],
+      {
+        role: 'user',
+        content: 'What was the first calculation we did? Verify with calculator.',
+      },
+    ];
+
+    spies.onSummarizeStart.mockClear();
+    spies.onSummarizeComplete.mockClear();
+
+    const crossRun = await runFullTurn({
+      payload: crossRunPayload,
+      agentProvider: Providers.ANTHROPIC,
+      summarizationProvider: Providers.ANTHROPIC,
+      summarizationModel: 'claude-haiku-4-5-20251001',
+      maxContextTokens: 2000,
+      instructions,
+      spies,
+      tokenCounter,
+    });
+
+    console.log(
+      `  Cross-run: messages=${crossRun.runMessages.length}, content=${crossRun.contentParts.length}, deltas=${spies.onMessageDelta.mock.calls.length}`,
+    );
+    // Content aggregator should have received response deltas even if getRunMessages is empty
+    expect(crossRun.contentParts.length + spies.onMessageDelta.mock.calls.length).toBeGreaterThan(
+      0,
+    );
+  });
+
+  test('tight context (maxContextTokens=200) does not infinite-loop', async () => {
+    const spies = createSpies();
+    const tokenCounter = await createTokenCounter();
+    const conversationPayload: PayloadMessage[] = [];
+
+    conversationPayload.push({ role: 'user', content: 'What is 42 * 58? Calculator.' });
+    const t1 = await runFullTurn({
+      payload: conversationPayload,
+      agentProvider: Providers.ANTHROPIC,
+      summarizationProvider: Providers.ANTHROPIC,
+      summarizationModel: 'claude-haiku-4-5-20251001',
+      maxContextTokens: 2000,
+      instructions,
+      spies,
+      tokenCounter,
+    });
+    conversationPayload.push({ role: 'assistant', content: getLastContent(t1.runMessages) });
+
+    conversationPayload.push({ role: 'user', content: 'Now compute 2436 + 1337. Calculator.' });
+    const t2 = await runFullTurn({
+      payload: conversationPayload,
+      agentProvider: Providers.ANTHROPIC,
+      summarizationProvider: Providers.ANTHROPIC,
+      summarizationModel: 'claude-haiku-4-5-20251001',
+      maxContextTokens: 2000,
+      instructions,
+      spies,
+      tokenCounter,
+    });
+    conversationPayload.push({ role: 'assistant', content: getLastContent(t2.runMessages) });
+
+    conversationPayload.push({ role: 'user', content: 'What is 100 / 4? Calculator.' });
+
+    let error: Error | undefined;
+    try {
+      await runFullTurn({
+        payload: conversationPayload,
+        agentProvider: Providers.ANTHROPIC,
+        summarizationProvider: Providers.ANTHROPIC,
+        summarizationModel: 'claude-haiku-4-5-20251001',
+        maxContextTokens: 200,
+        instructions,
+        spies,
+        tokenCounter,
+      });
+    } catch (err) {
+      error = err as Error;
+    }
+
+    // The key guarantee: the system terminates — no true infinite loop.
+    // With very tight context, the graph may either:
+    //   1. Complete normally (model responds within budget)
+    //   2. Hit recursion limit (bounded tool-call cycles)
+    //   3. Error with empty_messages (context too small for any message)
+    // All are valid termination modes.
+    if (error) {
+      const isCleanTermination =
+        error.message.includes('Recursion limit') || error.message.includes('empty_messages');
+
+      expect(isCleanTermination).toBe(true);
+    }
+
+    // Summarization may or may not fire depending on whether the budget
+    // allows any messages before the graph terminates. With 200 tokens
+    // and instructions at ~100 tokens, there may be no room for history,
+    // which correctly skips summarization.
+
+    console.log(
+      `  Tight context: summarize=${spies.onSummarizeStart.mock.calls.length}, error=${error?.message?.substring(0, 80) ?? 'none'}`,
+    );
+  });
+});
+
+// ---------------------------------------------------------------------------
+// OpenAI Tests
+// ---------------------------------------------------------------------------
+
+const hasOpenAI = process.env.OPENAI_API_KEY != null && process.env.OPENAI_API_KEY !== 'test';
+(hasOpenAI ? describe : describe.skip)('OpenAI Summarization E2E (LibreChat)', () => {
+  jest.setTimeout(180_000);
+
+  const instructions =
+    'You are a helpful math tutor. Use the calculator tool for ALL computations. Keep responses concise.';
+
+  test('multi-turn with cross-run summary continuity', async () => {
+    const spies = createSpies();
+    const tokenCounter = await createTokenCounter();
+    const conversationPayload: PayloadMessage[] = [];
+
+    const addTurn = async (userMsg: string, maxTokens: number) => {
+      conversationPayload.push({ role: 'user', content: userMsg });
+      const result = await runFullTurn({
+        payload: conversationPayload,
+        agentProvider: Providers.OPENAI,
+        summarizationProvider: Providers.OPENAI,
+        summarizationModel: 'gpt-4.1-mini',
+        maxContextTokens: maxTokens,
+        instructions,
+        spies,
+        tokenCounter,
+      });
+      conversationPayload.push({ role: 'assistant', content: getLastContent(result.runMessages) });
+      return result;
+    };
+
+    await addTurn('What is 1234 * 5678? Calculator.', 2000);
+    await addTurn('Compute sqrt(7006652) with calculator.', 1500);
+    await addTurn('Calculate 99*101 and 2^15. Calculator for each.', 1200);
+    await addTurn('What is 314159 * 271828? Calculator. Remind me of all prior results.', 800);
+
+    if (spies.onSummarizeStart.mock.calls.length === 0) {
+      await addTurn('Calculate 999999 / 7. Calculator.', 600);
+    }
+    if (spies.onSummarizeStart.mock.calls.length === 0) {
+      await addTurn('What is 42 + 58? Calculator.', 400);
+    }
+    if (spies.onSummarizeStart.mock.calls.length === 0) {
+      await addTurn('Calculate 7 * 13. Calculator.', 300);
+    }
+    if (spies.onSummarizeStart.mock.calls.length === 0) {
+      await addTurn('What is 100 - 37? Calculator.', 200);
+    }
+
+    expect(spies.onSummarizeStart.mock.calls.length).toBeGreaterThanOrEqual(1);
+    expect(spies.onSummarizeComplete.mock.calls.length).toBeGreaterThanOrEqual(1);
+
+    const complete = spies.onSummarizeComplete.mock.calls[0][0] as SummarizeCompleteEvent;
+    expect(getSummaryText(complete.summary!).length).toBeGreaterThan(10);
+    expect(complete.summary!.tokenCount).toBeGreaterThan(0);
+    expect(complete.summary!.summaryVersion).toBeGreaterThanOrEqual(1);
+    expect(complete.summary!.provider).toBe(Providers.OPENAI);
+
+    const summaryBlock = complete.summary!;
+    const crossRunPayload: PayloadMessage[] = [
+      {
+        role: 'assistant',
+        content: [
+          {
+            type: 'summary',
+            content: [{ type: 'text', text: getSummaryText(summaryBlock) }],
+            tokenCount: summaryBlock.tokenCount,
+          },
+        ],
+      },
+      conversationPayload[conversationPayload.length - 2],
+      conversationPayload[conversationPayload.length - 1],
+      { role: 'user', content: 'What was the first number we calculated? Verify with calculator.' },
+    ];
+
+    spies.onSummarizeStart.mockClear();
+    spies.onSummarizeComplete.mockClear();
+
+    const crossRun = await runFullTurn({
+      payload: crossRunPayload,
+      agentProvider: Providers.OPENAI,
+      summarizationProvider: Providers.OPENAI,
+      summarizationModel: 'gpt-4.1-mini',
+      maxContextTokens: 2000,
+      instructions,
+      spies,
+      tokenCounter,
+    });
+
+    console.log(
+      `  Cross-run: messages=${crossRun.runMessages.length}, content=${crossRun.contentParts.length}, deltas=${spies.onMessageDelta.mock.calls.length}`,
+    );
+    expect(crossRun.contentParts.length + spies.onMessageDelta.mock.calls.length).toBeGreaterThan(
+      0,
+    );
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Cross-provider: Anthropic agent, OpenAI summarizer
+// ---------------------------------------------------------------------------
+
+const hasBothProviders = hasAnthropic && hasOpenAI;
+(hasBothProviders ? describe : describe.skip)(
+  'Cross-provider Summarization E2E (LibreChat)',
+  () => {
+    jest.setTimeout(180_000);
+
+    const instructions =
+      'You are a math assistant. Use the calculator for every computation. Be brief.';
+
+    test('Anthropic agent with OpenAI summarizer', async () => {
+      const spies = createSpies();
+      const tokenCounter = await createTokenCounter();
+      const conversationPayload: PayloadMessage[] = [];
+
+      const addTurn = async (userMsg: string, maxTokens: number) => {
+        conversationPayload.push({ role: 'user', content: userMsg });
+        const result = await runFullTurn({
+          payload: conversationPayload,
+          agentProvider: Providers.ANTHROPIC,
+          summarizationProvider: Providers.OPENAI,
+          summarizationModel: 'gpt-4.1-mini',
+          maxContextTokens: maxTokens,
+          instructions,
+          spies,
+          tokenCounter,
+        });
+        conversationPayload.push({
+          role: 'assistant',
+          content: getLastContent(result.runMessages),
+        });
+        return result;
+      };
+
+      await addTurn('Compute 54321 * 12345 using calculator.', 2000);
+      await addTurn('Now calculate 670592745 / 99991. Calculator.', 1500);
+      await addTurn('What is sqrt(670592745)? Calculator.', 1000);
+      await addTurn('Compute 2^32 with calculator. List all prior results.', 600);
+
+      if (spies.onSummarizeStart.mock.calls.length === 0) {
+        await addTurn('13 * 17 * 19 = ? Calculator.', 400);
+      }
+
+      expect(spies.onSummarizeComplete.mock.calls.length).toBeGreaterThanOrEqual(1);
+      const complete = spies.onSummarizeComplete.mock.calls[0][0] as SummarizeCompleteEvent;
+
+      expect(complete.summary!.provider).toBe(Providers.OPENAI);
+      expect(complete.summary!.model).toBe('gpt-4.1-mini');
+      expect(getSummaryText(complete.summary!).length).toBeGreaterThan(10);
+    });
+  },
+);
--- a/packages/api/src/agents/initialize.ts
+++ b/packages/api/src/agents/initialize.ts
@ -32,6 +32,8 @@ import { generateArtifactsPrompt } from '~/prompts';
 import { getProviderConfig } from '~/endpoints';
 import { primeResources } from './resources';

+const DEFAULT_RESERVE_RATIO = 0.05;
+
 /**
 * Extended agent type with additional fields needed after initialization
 */
@ -40,6 +42,8 @@ export type InitializedAgent = Agent & {
  attachments: IMongoFile[];
  toolContextMap: Record<string, unknown>;
  maxContextTokens: number;
+  /** Pre-ratio context budget (agentMaxContextNum - maxOutputTokensNum). Used by createRun to apply a configurable reserve ratio. */
+  baseContextTokens?: number;
  useLegacyContent: boolean;
  resendFiles: boolean;
  tool_resources?: AgentToolResources;
@ -52,6 +56,8 @@ export type InitializedAgent = Agent & {
  toolDefinitions?: LCTool[];
  /** Precomputed flag indicating if any tools have defer_loading enabled (for efficient runtime checks) */
  hasDeferredTools?: boolean;
+  /** Maximum characters allowed in a single tool result before truncation. */
+  maxToolResultChars?: number;
 };

 /**
@ -302,7 +308,7 @@ export async function initializeAgent(
    hasDeferredTools: false,
  };

-  const { getOptions, overrideProvider } = getProviderConfig({
+  const { getOptions, overrideProvider, customEndpointConfig } = getProviderConfig({
    provider,
    appConfig: req.config,
  });
@ -396,11 +402,25 @@ export async function initializeAgent(

  const agentMaxContextNum = Number(agentMaxContextTokens) || 18000;
  const maxOutputTokensNum = Number(maxOutputTokens) || 0;
+  const baseContextTokens = agentMaxContextNum - maxOutputTokensNum;

  const finalAttachments: IMongoFile[] = (primedAttachments ?? [])
    .filter((a): a is TFile => a != null)
    .map((a) => a as unknown as IMongoFile);

+  const endpointConfigs = req.config?.endpoints;
+  const providerConfig =
+    customEndpointConfig ?? endpointConfigs?.[agent.provider as keyof typeof endpointConfigs];
+  const providerMaxToolResultChars =
+    providerConfig != null &&
+    typeof providerConfig === 'object' &&
+    !Array.isArray(providerConfig) &&
+    'maxToolResultChars' in providerConfig
+      ? (providerConfig.maxToolResultChars as number | undefined)
+      : undefined;
+  const maxToolResultCharsResolved =
+    providerMaxToolResultChars ?? endpointConfigs?.all?.maxToolResultChars;
+
  const initializedAgent: InitializedAgent = {
    ...agent,
    resendFiles,
@ -409,14 +429,16 @@ export async function initializeAgent(
    userMCPAuthMap,
    toolDefinitions,
    hasDeferredTools,
+    baseContextTokens,
    attachments: finalAttachments,
    toolContextMap: toolContextMap ?? {},
    useLegacyContent: !!options.useLegacyContent,
    tools: (tools ?? []) as GenericTool[] & string[],
+    maxToolResultChars: maxToolResultCharsResolved,
    maxContextTokens:
      maxContextTokens != null && maxContextTokens > 0
        ? maxContextTokens
-        : Math.round((agentMaxContextNum - maxOutputTokensNum) * 0.9),
+        : Math.max(1024, Math.round(baseContextTokens * (1 - DEFAULT_RESERVE_RATIO))),
  };

  return initializedAgent;
--- a/packages/api/src/agents/run.ts
+++ b/packages/api/src/agents/run.ts
@ -2,7 +2,9 @@ import { Run, Providers, Constants } from '@librechat/agents';
 import { providerEndpointMap, KnownEndpoints } from 'librechat-data-provider';
 import type { BaseMessage } from '@langchain/core/messages';
 import type {
+  SummarizationConfig as AgentSummarizationConfig,
  MultiAgentGraphConfig,
+  ContextPruningConfig,
  OpenAIClientOptions,
  StandardGraphConfig,
  LCToolRegistry,
@ -13,7 +15,7 @@ import type {
  LCTool,
 } from '@librechat/agents';
 import type { IUser } from '@librechat/data-schemas';
-import type { Agent } from 'librechat-data-provider';
+import type { Agent, SummarizationConfig } from 'librechat-data-provider';
 import type * as t from '~/types';
 import { resolveHeaders, createSafeUser } from '~/utils/env';

@ -162,6 +164,8 @@ export function getReasoningKey(
 type RunAgent = Omit<Agent, 'tools'> & {
  tools?: GenericTool[];
  maxContextTokens?: number;
+  /** Pre-ratio context budget from initializeAgent. */
+  baseContextTokens?: number;
  useLegacyContent?: boolean;
  toolContextMap?: Record<string, string>;
  toolRegistry?: LCToolRegistry;
@ -169,6 +173,13 @@ type RunAgent = Omit<Agent, 'tools'> & {
  toolDefinitions?: LCTool[];
  /** Precomputed flag indicating if any tools have defer_loading enabled */
  hasDeferredTools?: boolean;
+  /** Optional per-agent summarization overrides */
+  summarization?: SummarizationConfig;
+  /**
+   * Maximum characters allowed in a single tool result before truncation.
+   * Overrides the default computed from maxContextTokens.
+   */
+  maxToolResultChars?: number;
 };

 /**
@ -196,6 +207,8 @@ export async function createRun({
  tokenCounter,
  customHandlers,
  indexTokenCountMap,
+  summarizationConfig,
+  initialSummary,
  streaming = true,
  streamUsage = true,
 }: {
@ -208,6 +221,9 @@ export async function createRun({
  user?: IUser;
  /** Message history for extracting previously discovered tools */
  messages?: BaseMessage[];
+  summarizationConfig?: SummarizationConfig;
+  /** Cross-run summary from formatAgentMessages, forwarded to AgentContext */
+  initialSummary?: { text: string; tokenCount: number };
 } & Pick<RunConfig, 'tokenCounter' | 'customHandlers' | 'indexTokenCountMap'>): Promise<
  Run<IState>
 > {
@ -228,6 +244,28 @@ export async function createRun({

  const agentInputs: AgentInputs[] = [];
  const buildAgentContext = (agent: RunAgent) => {
+    const selfProvider =
+      (providerEndpointMap[
+        agent.provider as keyof typeof providerEndpointMap
+      ] as unknown as string) ?? agent.provider;
+    const selfModel = agent.model_parameters?.model ?? (agent.model as string | undefined);
+
+    const resolvedSummarizationConfig: SummarizationConfig | undefined = agent.summarization ??
+      summarizationConfig ?? {
+        enabled: true,
+        provider: selfProvider,
+        model: selfModel,
+      };
+
+    const resolvedSummarizationProvider = resolvedSummarizationConfig?.provider;
+    const resolvedSummarizationModel = resolvedSummarizationConfig?.model;
+    const hasSummarizationProvider =
+      typeof resolvedSummarizationProvider === 'string' &&
+      resolvedSummarizationProvider.trim().length > 0;
+    const hasSummarizationModel =
+      typeof resolvedSummarizationModel === 'string' &&
+      resolvedSummarizationModel.trim().length > 0;
+
    const provider =
      (providerEndpointMap[
        agent.provider as keyof typeof providerEndpointMap
@ -299,6 +337,21 @@ export async function createRun({
      }
    }

+    // Apply configurable reserve ratio when available, falling back to the
+    // pre-computed maxContextTokens from initializeAgent.
+    const reserveRatio = resolvedSummarizationConfig?.reserveRatio;
+    const ratioComputed =
+      reserveRatio != null &&
+      reserveRatio > 0 &&
+      reserveRatio < 1 &&
+      agent.baseContextTokens != null
+        ? Math.max(1024, Math.round(agent.baseContextTokens * (1 - reserveRatio)))
+        : null;
+    const effectiveMaxContextTokens =
+      ratioComputed != null
+        ? Math.min(agent.maxContextTokens ?? ratioComputed, ratioComputed)
+        : agent.maxContextTokens;
+
    const reasoningKey = getReasoningKey(provider, llmConfig, agent.endpoint);
    const agentInput: AgentInputs = {
      provider,
@ -310,9 +363,38 @@ export async function createRun({
      instructions: systemContent,
      name: agent.name ?? undefined,
      toolRegistry: agent.toolRegistry,
-      maxContextTokens: agent.maxContextTokens,
+      maxContextTokens: effectiveMaxContextTokens,
      useLegacyContent: agent.useLegacyContent ?? false,
      discoveredTools: discoveredTools.size > 0 ? Array.from(discoveredTools) : undefined,
+      summarizationEnabled:
+        resolvedSummarizationConfig != null &&
+        resolvedSummarizationConfig.enabled !== false &&
+        hasSummarizationProvider &&
+        hasSummarizationModel,
+      summarizationConfig: resolvedSummarizationConfig
+        ? ({
+            trigger:
+              resolvedSummarizationConfig.trigger?.type &&
+              resolvedSummarizationConfig.trigger?.value
+                ? {
+                    type: resolvedSummarizationConfig.trigger.type,
+                    value: resolvedSummarizationConfig.trigger.value,
+                  }
+                : undefined,
+            provider: resolvedSummarizationConfig.provider,
+            model: resolvedSummarizationConfig.model,
+            parameters: resolvedSummarizationConfig.parameters,
+            prompt: resolvedSummarizationConfig.prompt,
+            updatePrompt: resolvedSummarizationConfig.updatePrompt,
+            reserveRatio: resolvedSummarizationConfig.reserveRatio,
+            maxSummaryTokens: resolvedSummarizationConfig.maxSummaryTokens,
+          } satisfies AgentSummarizationConfig)
+        : undefined,
+      initialSummary,
+      contextPruningConfig: resolvedSummarizationConfig?.contextPruning as
+        | ContextPruningConfig
+        | undefined,
+      maxToolResultChars: agent.maxToolResultChars,
    };
    agentInputs.push(agentInput);
  };
--- a/packages/api/src/agents/usage.spec.ts
+++ b/packages/api/src/agents/usage.spec.ts
@ -108,6 +108,46 @@ describe('recordCollectedUsage', () => {
    });
  });

+  describe('summarization usage segregation', () => {
+    it('keeps summarization usage out of message token rollups while still spending it', async () => {
+      const collectedUsage: UsageMetadata[] = [
+        {
+          usage_type: 'message',
+          input_tokens: 120,
+          output_tokens: 40,
+          model: 'gpt-4',
+        },
+        {
+          usage_type: 'summarization',
+          input_tokens: 30,
+          output_tokens: 12,
+          model: 'gpt-4.1-mini',
+        },
+      ];
+
+      const result = await recordCollectedUsage(deps, {
+        ...baseParams,
+        collectedUsage,
+      });
+
+      expect(result).toEqual({ input_tokens: 120, output_tokens: 40 });
+      expect(mockSpendTokens).toHaveBeenCalledTimes(2);
+      expect(mockSpendTokens).toHaveBeenNthCalledWith(
+        1,
+        expect.objectContaining({ context: 'message', model: 'gpt-4' }),
+        expect.any(Object),
+      );
+      expect(mockSpendTokens).toHaveBeenNthCalledWith(
+        2,
+        expect.objectContaining({
+          context: 'summarization',
+          model: 'gpt-4.1-mini',
+        }),
+        expect.any(Object),
+      );
+    });
+  });
+
  describe('parallel execution (multiple agents)', () => {
    it('should handle parallel agents with independent input tokens', async () => {
      const collectedUsage: UsageMetadata[] = [
--- a/packages/api/src/agents/usage.ts
+++ b/packages/api/src/agents/usage.ts
@ -73,15 +73,26 @@ export async function recordCollectedUsage(
    return;
  }

-  const firstUsage = collectedUsage[0];
+  const messageUsages: UsageMetadata[] = [];
+  const summarizationUsages: UsageMetadata[] = [];
+  for (const usage of collectedUsage) {
+    if (usage == null) {
+      continue;
+    }
+    (usage.usage_type === 'summarization' ? summarizationUsages : messageUsages).push(usage);
+  }
+
+  const firstUsage = messageUsages[0];
  const input_tokens =
-    (firstUsage?.input_tokens || 0) +
-    (Number(firstUsage?.input_token_details?.cache_creation) ||
-      Number(firstUsage?.cache_creation_input_tokens) ||
-      0) +
-    (Number(firstUsage?.input_token_details?.cache_read) ||
-      Number(firstUsage?.cache_read_input_tokens) ||
-      0);
+    firstUsage == null
+      ? 0
+      : (firstUsage.input_tokens || 0) +
+        (Number(firstUsage.input_token_details?.cache_creation) ||
+          Number(firstUsage.cache_creation_input_tokens) ||
+          0) +
+        (Number(firstUsage.input_token_details?.cache_read) ||
+          Number(firstUsage.cache_read_input_tokens) ||
+          0);

  let total_output_tokens = 0;

@ -90,7 +101,7 @@ export async function recordCollectedUsage(

  const allDocs: PreparedEntry[] = [];

-  for (const usage of collectedUsage) {
+  for (const usage of messageUsages) {
    if (!usage) {
      continue;
    }
@ -179,6 +190,97 @@ export async function recordCollectedUsage(
    }
  }

+  const summarizationDocs: PreparedEntry[] = [];
+
+  for (const usage of summarizationUsages) {
+    if (!usage) {
+      continue;
+    }
+
+    const cache_creation =
+      Number(usage.input_token_details?.cache_creation) ||
+      Number(usage.cache_creation_input_tokens) ||
+      0;
+    const cache_read =
+      Number(usage.input_token_details?.cache_read) || Number(usage.cache_read_input_tokens) || 0;
+
+    const txMetadata: TxMetadata = {
+      context: 'summarization',
+      balance,
+      transactions,
+      conversationId,
+      user,
+      endpointTokenConfig,
+      model: usage.model ?? model,
+    };
+
+    if (useBulk) {
+      const entries =
+        cache_creation > 0 || cache_read > 0
+          ? prepareStructuredTokenSpend(
+              txMetadata,
+              {
+                promptTokens: {
+                  input: usage.input_tokens,
+                  write: cache_creation,
+                  read: cache_read,
+                },
+                completionTokens: usage.output_tokens,
+              },
+              pricing,
+            )
+          : prepareTokenSpend(
+              txMetadata,
+              {
+                promptTokens: usage.input_tokens,
+                completionTokens: usage.output_tokens,
+              },
+              pricing,
+            );
+      summarizationDocs.push(...entries);
+      continue;
+    }
+
+    if (cache_creation > 0 || cache_read > 0) {
+      deps
+        .spendStructuredTokens(txMetadata, {
+          promptTokens: {
+            input: usage.input_tokens,
+            write: cache_creation,
+            read: cache_read,
+          },
+          completionTokens: usage.output_tokens,
+        })
+        .catch((err) => {
+          logger.error(
+            '[packages/api #recordCollectedUsage] Error spending structured summarization tokens',
+            err,
+          );
+        });
+      continue;
+    }
+
+    deps
+      .spendTokens(txMetadata, {
+        promptTokens: usage.input_tokens,
+        completionTokens: usage.output_tokens,
+      })
+      .catch((err) => {
+        logger.error(
+          '[packages/api #recordCollectedUsage] Error spending summarization tokens',
+          err,
+        );
+      });
+  }
+
+  if (useBulk && summarizationDocs.length > 0) {
+    try {
+      await bulkWriteTransactions({ user, docs: summarizationDocs }, bulkWriteOps);
+    } catch (err) {
+      logger.error('[packages/api #recordCollectedUsage] Error in summarization bulk write', err);
+    }
+  }
+
  return {
    input_tokens,
    output_tokens: total_output_tokens,
--- a/packages/api/src/app/AppService.spec.ts
+++ b/packages/api/src/app/AppService.spec.ts
@ -181,6 +181,43 @@ describe('AppService', () => {
    );
  });

+  it('should enable summarization when it is configured without enabled flag', async () => {
+    const config = {
+      summarization: {
+        prompt: 'Summarize with emphasis on next actions',
+      },
+    } as Partial<TCustomConfig> & { summarization: Record<string, unknown> };
+
+    const result = await AppService({ config });
+    expect(result).toEqual(
+      expect.objectContaining({
+        summarization: expect.objectContaining({
+          enabled: true,
+          prompt: 'Summarize with emphasis on next actions',
+        }),
+      }),
+    );
+  });
+
+  it('should preserve explicit summarization disable flag', async () => {
+    const config = {
+      summarization: {
+        enabled: false,
+        prompt: 'Ignored while disabled',
+      },
+    } as Partial<TCustomConfig> & { summarization: Record<string, unknown> };
+
+    const result = await AppService({ config });
+    expect(result).toEqual(
+      expect.objectContaining({
+        summarization: expect.objectContaining({
+          enabled: false,
+          prompt: 'Ignored while disabled',
+        }),
+      }),
+    );
+  });
+
  it('should load and format tools accurately with defined structure', async () => {
    const config = {};

--- a/packages/api/src/stream/interfaces/IJobStore.ts
+++ b/packages/api/src/stream/interfaces/IJobStore.ts
@ -65,12 +65,18 @@ export interface SerializableJobData {
 * ```
 */
 export interface UsageMetadata {
+  /** Logical usage bucket for accounting/reporting. Defaults to model response usage. */
+  usage_type?: 'message' | 'summarization';
  /** Total input tokens (prompt tokens) */
  input_tokens?: number;
  /** Total output tokens (completion tokens) */
  output_tokens?: number;
+  /** Total billed tokens when provided by the model/runtime */
+  total_tokens?: number;
  /** Model identifier that generated this usage */
  model?: string;
+  /** Provider identifier that generated this usage */
+  provider?: string;
  /**
   * OpenAI-style cache token details.
   * Present for OpenAI models (GPT-4, o1, etc.)
--- a/packages/api/src/utils/index.ts
+++ b/packages/api/src/utils/index.ts
@ -21,6 +21,7 @@ export * from './text';
 export * from './yaml';
 export * from './http';
 export * from './tokens';
+export * from './tokenMap';
 export * from './url';
 export * from './message';
 export * from './tracing';
--- a/packages/api/src/utils/tokenMap.ts
+++ b/packages/api/src/utils/tokenMap.ts
@ -0,0 +1,44 @@
+import type { BaseMessage } from '@langchain/core/messages';
+
+/** Signature for a function that counts tokens in a LangChain message. */
+export type TokenCounter = (message: BaseMessage) => number;
+
+/**
+ * Lazily fills missing token counts for formatted LangChain messages.
+ * Preserves precomputed counts and only computes undefined indices.
+ *
+ * This is used after `formatAgentMessages` to ensure every message index
+ * has a token count before passing `indexTokenCountMap` to the agent run.
+ */
+export function hydrateMissingIndexTokenCounts({
+  messages,
+  indexTokenCountMap,
+  tokenCounter,
+}: {
+  messages: BaseMessage[];
+  indexTokenCountMap: Record<number, number | undefined> | undefined;
+  tokenCounter: TokenCounter;
+}): Record<number, number> {
+  const hydratedMap: Record<number, number> = {};
+
+  if (indexTokenCountMap) {
+    for (const [index, tokenCount] of Object.entries(indexTokenCountMap)) {
+      if (typeof tokenCount === 'number' && Number.isFinite(tokenCount) && tokenCount > 0) {
+        hydratedMap[Number(index)] = tokenCount;
+      }
+    }
+  }
+
+  for (let i = 0; i < messages.length; i++) {
+    if (
+      typeof hydratedMap[i] === 'number' &&
+      Number.isFinite(hydratedMap[i]) &&
+      hydratedMap[i] > 0
+    ) {
+      continue;
+    }
+    hydratedMap[i] = tokenCounter(messages[i]);
+  }
+
+  return hydratedMap;
+}
--- a/packages/data-provider/src/config.ts
+++ b/packages/data-provider/src/config.ts
@ -205,6 +205,8 @@ export const baseEndpointSchema = z.object({
    .optional(),
  titleEndpoint: z.string().optional(),
  titlePromptTemplate: z.string().optional(),
+  /** Maximum characters allowed in a single tool result before truncation. */
+  maxToolResultChars: z.number().positive().optional(),
 });

 export type TBaseEndpoint = z.infer<typeof baseEndpointSchema>;
@ -948,6 +950,34 @@ export const memorySchema = z.object({

 export type TMemoryConfig = DeepPartial<z.infer<typeof memorySchema>>;

+export const summarizationTriggerSchema = z.object({
+  type: z.string(),
+  value: z.number().positive(),
+});
+
+export const contextPruningSchema = z.object({
+  enabled: z.boolean().optional(),
+  keepLastAssistants: z.number().min(0).max(10).optional(),
+  softTrimRatio: z.number().min(0).max(1).optional(),
+  hardClearRatio: z.number().min(0).max(1).optional(),
+  minPrunableToolChars: z.number().min(0).optional(),
+});
+
+export const summarizationConfigSchema = z.object({
+  enabled: z.boolean().optional(),
+  provider: z.string().optional(),
+  model: z.string().optional(),
+  parameters: z.record(z.any()).optional(),
+  trigger: summarizationTriggerSchema.optional(),
+  prompt: z.string().optional(),
+  updatePrompt: z.string().optional(),
+  reserveRatio: z.number().min(0).max(1).optional(),
+  maxSummaryTokens: z.number().positive().optional(),
+  contextPruning: contextPruningSchema.optional(),
+});
+
+export type SummarizationConfig = DeepPartial<z.infer<typeof summarizationConfigSchema>>;
+
 const customEndpointsSchema = z.array(endpointSchema.partial()).optional();

 export const configSchema = z.object({
@ -956,6 +986,7 @@ export const configSchema = z.object({
  ocr: ocrSchema.optional(),
  webSearch: webSearchSchema.optional(),
  memory: memorySchema.optional(),
+  summarization: summarizationConfigSchema.optional(),
  secureImageLinks: z.boolean().optional(),
  imageOutputType: z.nativeEnum(EImageOutputType).default(EImageOutputType.PNG),
  includedTools: z.array(z.string()).optional(),
--- a/packages/data-provider/src/types/agents.ts
+++ b/packages/data-provider/src/types/agents.ts
@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/no-namespace */
 import { StepTypes, ContentTypes, ToolCallTypes } from './runs';
 import type { TAttachment, TPlugin } from 'src/schemas';
-import type { FunctionToolCall } from './assistants';
+import type { FunctionToolCall, SummaryContentPart } from './assistants';

 export namespace Agents {
  export type MessageType = 'human' | 'ai' | 'generic' | 'system' | 'function' | 'tool' | 'remove';
@ -53,6 +53,8 @@ export namespace Agents {
    | MessageContentImageUrl
    | MessageContentVideoUrl
    | MessageContentInputAudio
+    | SummaryContentPart
+    | ToolCallContent
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    | (Record<string, any> & { type?: ContentTypes | string })
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
@ -187,6 +189,7 @@ export namespace Agents {
    /** Group ID for parallel content - parts with same groupId are displayed in columns */
    groupId?: number; // #new
    stepDetails: StepDetails;
+    summary?: SummaryContentPart;
    usage: null | object;
  };

@ -313,6 +316,28 @@ export namespace Agents {
    | ContentTypes.VIDEO_URL
    | ContentTypes.INPUT_AUDIO
    | string;
+
+  export interface SummarizeStartEvent {
+    agentId: string;
+    provider: string;
+    model?: string;
+    messagesToRefineCount: number;
+    summaryVersion: number;
+  }
+
+  export interface SummarizeDeltaEvent {
+    id: string;
+    delta: {
+      summary: SummaryContentPart;
+    };
+  }
+
+  export interface SummarizeCompleteEvent {
+    id: string;
+    agentId: string;
+    summary?: SummaryContentPart;
+    error?: string;
+  }
 }

 export type ToolCallResult = {
--- a/packages/data-provider/src/types/assistants.ts
+++ b/packages/data-provider/src/types/assistants.ts
@ -521,6 +521,21 @@ export type ContentPart = (

 export type TextData = (Text & PartMetadata) | undefined;

+export type SummaryContentPart = {
+  type: ContentTypes.SUMMARY;
+  content?: Agents.MessageContentComplex[];
+  tokenCount?: number;
+  summarizing?: boolean;
+  summaryVersion?: number;
+  model?: string;
+  provider?: string;
+  createdAt?: string;
+  boundary?: {
+    messageId: string;
+    contentIndex: number;
+  };
+};
+
 export type TMessageContentParts =
  | ({
      type: ContentTypes.ERROR;
@ -545,6 +560,7 @@ export type TMessageContentParts =
        PartMetadata;
    } & ContentMetadata)
  | ({ type: ContentTypes.IMAGE_FILE; image_file: ImageFile & PartMetadata } & ContentMetadata)
+  | (SummaryContentPart & ContentMetadata)
  | (Agents.AgentUpdate & ContentMetadata)
  | (Agents.MessageContentImageUrl & ContentMetadata)
  | (Agents.MessageContentVideoUrl & ContentMetadata)
--- a/packages/data-provider/src/types/runs.ts
+++ b/packages/data-provider/src/types/runs.ts
@ -8,6 +8,7 @@ export enum ContentTypes {
  VIDEO_URL = 'video_url',
  INPUT_AUDIO = 'input_audio',
  AGENT_UPDATE = 'agent_update',
+  SUMMARY = 'summary',
  ERROR = 'error',
 }

@ -24,3 +25,16 @@ export enum ToolCallTypes {
  /* Agents Tool Call */
  TOOL_CALL = 'tool_call',
 }
+
+/** Event names dispatched by the agent graph and consumed by step handlers. */
+export enum StepEvents {
+  ON_RUN_STEP = 'on_run_step',
+  ON_AGENT_UPDATE = 'on_agent_update',
+  ON_MESSAGE_DELTA = 'on_message_delta',
+  ON_REASONING_DELTA = 'on_reasoning_delta',
+  ON_RUN_STEP_DELTA = 'on_run_step_delta',
+  ON_RUN_STEP_COMPLETED = 'on_run_step_completed',
+  ON_SUMMARIZE_START = 'on_summarize_start',
+  ON_SUMMARIZE_DELTA = 'on_summarize_delta',
+  ON_SUMMARIZE_COMPLETE = 'on_summarize_complete',
+}
--- a/packages/data-schemas/src/app/service.ts
+++ b/packages/data-schemas/src/app/service.ts
@ -1,4 +1,8 @@
-import { EModelEndpoint, getConfigDefaults } from 'librechat-data-provider';
+import {
+  EModelEndpoint,
+  getConfigDefaults,
+  summarizationConfigSchema,
+} from 'librechat-data-provider';
 import type { TCustomConfig, FileSources, DeepPartial } from 'librechat-data-provider';
 import type { AppConfig, FunctionTool } from '~/types/app';
 import { loadDefaultInterface } from './interface';
@ -9,6 +13,25 @@ import { processModelSpecs } from './specs';
 import { loadMemoryConfig } from './memory';
 import { loadEndpoints } from './endpoints';
 import { loadOCRConfig } from './ocr';
+import logger from '~/config/winston';
+
+function loadSummarizationConfig(config: DeepPartial<TCustomConfig>): AppConfig['summarization'] {
+  const raw = config.summarization;
+  if (!raw || typeof raw !== 'object') {
+    return undefined;
+  }
+
+  const parsed = summarizationConfigSchema.safeParse(raw);
+  if (!parsed.success) {
+    logger.warn('[AppService] Invalid summarization config', parsed.error.flatten());
+    return undefined;
+  }
+
+  return {
+    ...parsed.data,
+    enabled: parsed.data.enabled !== false,
+  };
+}

 export type Paths = {
  root: string;
@ -41,6 +64,7 @@ export const AppService = async (params?: {
  const ocr = loadOCRConfig(config.ocr);
  const webSearch = loadWebSearchConfig(config.webSearch);
  const memory = loadMemoryConfig(config.memory);
+  const summarization = loadSummarizationConfig(config);
  const filteredTools = config.filteredTools;
  const includedTools = config.includedTools;
  const fileStrategy = (config.fileStrategy ?? configDefaults.fileStrategy) as
@ -76,18 +100,19 @@ export const AppService = async (params?: {
    speech,
    balance,
    actions,
-    transactions,
-    mcpConfig: mcpServersConfig,
-    mcpSettings,
    webSearch,
+    mcpSettings,
+    transactions,
    fileStrategy,
    registration,
    filteredTools,
    includedTools,
+    summarization,
    availableTools,
    imageOutputType,
    interfaceConfig,
    turnstileConfig,
+    mcpConfig: mcpServersConfig,
    fileStrategies: config.fileStrategies,
  };

--- a/packages/data-schemas/src/types/app.ts
+++ b/packages/data-schemas/src/types/app.ts
@ -11,6 +11,7 @@ import type {
  TCustomEndpoints,
  TAssistantEndpoint,
  TAnthropicEndpoint,
+  SummarizationConfig,
 } from 'librechat-data-provider';

 export type JsonSchemaType = {
@ -29,6 +30,10 @@ export type ConvertJsonSchemaToZodOptions = {
  transformOneOfAnyOf?: boolean;
 };

+export type AppSummarizationConfig = SummarizationConfig & {
+  enabled: boolean;
+};
+
 export interface FunctionTool {
  type: 'function';
  function: {
@ -56,6 +61,8 @@ export interface AppConfig {
  };
  /** Memory configuration */
  memory?: TMemoryConfig;
+  /** Summarization configuration */
+  summarization?: AppSummarizationConfig;
  /** Web search configuration */
  webSearch?: TCustomConfig['webSearch'];
  /** File storage strategy ('local', 's3', 'firebase', 'azure_blob') */