diff --git a/api/server/routes/agents/actions.js b/api/server/routes/agents/actions.js
index 6133ee24e1..eab7c908aa 100644
--- a/api/server/routes/agents/actions.js
+++ b/api/server/routes/agents/actions.js
@@ -3,8 +3,12 @@ const { nanoid } = require('nanoid');
 const { logger } = require('@librechat/data-schemas');
 const {
   generateCheckAccess,
+  planAgentActionUpdate,
   isActionDomainAllowed,
+  legacyActionDomainEncode,
   validateActionOAuthMetadata,
+  ACTION_CREDENTIAL_REFRESH_MESSAGE,
+  buildActionOAuthTokenDeleteQueries,
 } = require('@librechat/api');
 const {
   Permissions,
@@ -16,17 +20,19 @@ const {
   validateActionDomain,
   validateAndParseOpenAPISpec,
 } = require('librechat-data-provider');
-const {
-  legacyDomainEncode,
-  encryptMetadata,
-  domainParser,
-} = require('~/server/services/ActionService');
+const { encryptMetadata, domainParser } = require('~/server/services/ActionService');
 const { findAccessibleResources } = require('~/server/services/PermissionService');
 const db = require('~/models');
 const { canAccessAgentResource } = require('~/server/middleware');
 
 const router = express.Router();
 
+async function deleteActionOAuthTokens(action_id) {
+  await Promise.all(
+    buildActionOAuthTokenDeleteQueries(action_id).map((query) => db.deleteTokens(query)),
+  );
+}
+
 const checkAgentCreate = generateCheckAccess({
   permissionType: PermissionTypes.AGENTS,
   permissions: [Permissions.USE, Permissions.CREATE],
@@ -92,7 +98,7 @@ router.post(
         return res.status(400).json({ message: 'No functions provided' });
       }
 
-      let metadata = await encryptMetadata(removeNullishValues(_metadata, true));
+      const metadata = await encryptMetadata(removeNullishValues(_metadata, true));
       const appConfig = req.config;
 
       // SECURITY: Validate the OpenAPI spec and extract the server URL
@@ -135,15 +141,16 @@ router.post(
         return res.status(400).json({ message: 'No domain provided' });
       }
 
-      const legacyDomain = legacyDomainEncode(metadata.domain);
+      const legacyDomain = legacyActionDomainEncode(metadata.domain);
 
-      const action_id = _action_id ?? nanoid();
+      const requestedActionId = _action_id;
+      const action_id = requestedActionId ?? nanoid();
       const initialPromises = [];
 
       // Permissions already validated by middleware - load agent directly
       initialPromises.push(db.getAgent({ id: agent_id }));
-      if (_action_id) {
-        initialPromises.push(db.getActions({ action_id }, true));
+      if (requestedActionId) {
+        initialPromises.push(db.getActions({ action_id: requestedActionId }, true));
       }
 
       /** @type {[Agent, [Action|undefined]]} */
@@ -152,53 +159,51 @@ router.post(
         return res.status(404).json({ message: 'Agent not found for adding action' });
       }
 
-      if (actions_result && actions_result.length) {
-        const action = actions_result[0];
-        if (action.agent_id !== agent_id) {
+      const storedAction = actions_result?.[0];
+      if (storedAction) {
+        if (storedAction.agent_id !== agent_id) {
           return res.status(403).json({ message: 'Action does not belong to this agent' });
         }
-        metadata = { ...action.metadata, ...metadata };
+      }
+
+      const { actions: agentActions = [], tools: agentTools = [], author: agent_author } = agent;
+      const plannedUpdate = planAgentActionUpdate({
+        agentActions,
+        agentTools,
+        incomingFunctions: functions,
+        incomingMetadata: metadata,
+        actionId: action_id,
+        requestedActionId,
+        encodedDomain,
+        legacyDomain,
+        previousLegacyDomain: legacyActionDomainEncode(storedAction?.metadata?.domain),
+        storedAction,
+      });
+
+      if (plannedUpdate.requiresCredentialRefresh) {
+        return res.status(400).json({
+          message: ACTION_CREDENTIAL_REFRESH_MESSAGE,
+        });
       }
 
       try {
-        await validateActionOAuthMetadata(metadata.auth, appConfig?.actions?.allowedAddresses);
+        await validateActionOAuthMetadata(
+          plannedUpdate.metadata.auth,
+          appConfig?.actions?.allowedAddresses,
+        );
       } catch (error) {
         return res.status(400).json({ message: error.message });
       }
 
-      const { actions: _actions = [], author: agent_author } = agent ?? {};
-      const actions = [];
-      for (const action of _actions) {
-        const [_action_domain, current_action_id] = action.split(actionDelimiter);
-        if (current_action_id === action_id) {
-          continue;
-        }
-
-        actions.push(action);
+      if (plannedUpdate.deleteOAuthTokens && requestedActionId) {
+        // Keep the callback URL stable while preventing old OAuth tokens from following a new target.
+        await deleteActionOAuthTokens(requestedActionId);
       }
 
-      actions.push(`${encodedDomain}${actionDelimiter}${action_id}`);
-
-      /** @type {string[]}} */
-      const { tools: _tools = [] } = agent;
-
-      const shouldRemoveAgentTool = (tool) => {
-        if (!tool) {
-          return false;
-        }
-        return (
-          tool.includes(encodedDomain) || tool.includes(legacyDomain) || tool.includes(action_id)
-        );
-      };
-
-      const tools = _tools
-        .filter((tool) => !shouldRemoveAgentTool(tool))
-        .concat(functions.map((tool) => `${tool.function.name}${actionDelimiter}${encodedDomain}`));
-
       // Force version update since actions are changing
       const updatedAgent = await db.updateAgent(
         { id: agent_id },
-        { tools, actions },
+        { tools: plannedUpdate.tools, actions: plannedUpdate.actions },
         {
           updatingUserId: req.user.id,
           forceVersion: true,
@@ -206,14 +211,21 @@ router.post(
       );
 
       // Only update user field for new actions
-      const actionUpdateData = { metadata, agent_id };
+      const actionUpdateData = {
+        action_id: plannedUpdate.actionId,
+        metadata: plannedUpdate.metadata,
+        agent_id,
+      };
       if (!actions_result || !actions_result.length) {
         // For new actions, use the agent owner's user ID
         actionUpdateData.user = agent_author || req.user.id;
       }
 
-      /** @type {[Action]} */
-      const updatedAction = await db.updateAction({ action_id, agent_id }, actionUpdateData);
+      /** @type {Action} */
+      const updatedAction = await db.updateAction(
+        { action_id: requestedActionId ?? action_id, agent_id },
+        actionUpdateData,
+      );
 
       const sensitiveFields = ['api_key', 'oauth_client_id', 'oauth_client_secret'];
       for (let field of sensitiveFields) {
diff --git a/packages/api/src/actions/credentials.spec.ts b/packages/api/src/actions/credentials.spec.ts
new file mode 100644
index 0000000000..d10b0410ca
--- /dev/null
+++ b/packages/api/src/actions/credentials.spec.ts
@@ -0,0 +1,183 @@
+jest.mock(
+  'librechat-data-provider',
+  () => ({
+    AuthTypeEnum: {
+      ServiceHttp: 'service_http',
+      OAuth: 'oauth',
+      None: 'none',
+    },
+    AuthorizationTypeEnum: {
+      Bearer: 'bearer',
+    },
+    TokenExchangeMethodEnum: {
+      DefaultPost: 'default_post',
+    },
+    validateAndParseOpenAPISpec: (specString: string) => {
+      const spec = JSON.parse(specString) as { servers?: Array<{ url?: string }> };
+      return {
+        status: true,
+        spec,
+        serverUrl: spec.servers?.[0]?.url,
+      };
+    },
+  }),
+  { virtual: true },
+);
+
+import {
+  AuthTypeEnum,
+  AuthorizationTypeEnum,
+  TokenExchangeMethodEnum,
+} from 'librechat-data-provider';
+import type { ActionMetadata } from 'librechat-data-provider';
+import { mergeActionMetadataForUpdate } from './credentials';
+
+const specFor = (serverUrl: string): string =>
+  JSON.stringify({
+    openapi: '3.0.0',
+    info: { title: 'Action API', version: '1.0.0' },
+    servers: [{ url: serverUrl }],
+    paths: {
+      '/echo': {
+        get: {
+          operationId: 'echo',
+          responses: { 200: { description: 'OK' } },
+        },
+      },
+    },
+  });
+
+const serviceMetadata = (serverUrl = 'https://api.example.com/v1'): ActionMetadata => ({
+  domain: 'https://api.example.com',
+  raw_spec: specFor(serverUrl),
+  api_key: 'encrypted-owner-key',
+  auth: {
+    type: AuthTypeEnum.ServiceHttp,
+    authorization_type: AuthorizationTypeEnum.Bearer,
+  },
+});
+
+describe('mergeActionMetadataForUpdate', () => {
+  it('preserves existing service credentials when the action target is unchanged', () => {
+    const incoming: ActionMetadata = {
+      domain: 'https://api.example.com',
+      raw_spec: specFor('https://api.example.com/v1'),
+    };
+
+    const result = mergeActionMetadataForUpdate({
+      storedMetadata: serviceMetadata(),
+      incomingMetadata: incoming,
+    });
+
+    expect(result.targetChanged).toBe(false);
+    expect(result.requiresCredentialRefresh).toBe(false);
+    expect(result.metadata.api_key).toBe('encrypted-owner-key');
+  });
+
+  it('requires a fresh service credential when the domain changes', () => {
+    const incoming: ActionMetadata = {
+      domain: 'https://attacker.example',
+      raw_spec: specFor('https://attacker.example/v1'),
+    };
+
+    const result = mergeActionMetadataForUpdate({
+      storedMetadata: serviceMetadata(),
+      incomingMetadata: incoming,
+    });
+
+    expect(result.targetChanged).toBe(true);
+    expect(result.requiresCredentialRefresh).toBe(true);
+    expect(result.metadata.api_key).toBeUndefined();
+  });
+
+  it('treats OpenAPI server path changes as target changes', () => {
+    const incoming: ActionMetadata = {
+      domain: 'https://api.example.com',
+      raw_spec: specFor('https://api.example.com/debug'),
+    };
+
+    const result = mergeActionMetadataForUpdate({
+      storedMetadata: serviceMetadata(),
+      incomingMetadata: incoming,
+    });
+
+    expect(result.targetChanged).toBe(true);
+    expect(result.requiresCredentialRefresh).toBe(true);
+    expect(result.metadata.api_key).toBeUndefined();
+  });
+
+  it('allows target changes when the request supplies a fresh service credential', () => {
+    const incoming: ActionMetadata = {
+      domain: 'https://api.example.com',
+      raw_spec: specFor('https://api.example.com/v2'),
+      api_key: 'encrypted-new-key',
+      auth: {
+        type: AuthTypeEnum.ServiceHttp,
+        authorization_type: AuthorizationTypeEnum.Bearer,
+      },
+    };
+
+    const result = mergeActionMetadataForUpdate({
+      storedMetadata: serviceMetadata(),
+      incomingMetadata: incoming,
+    });
+
+    expect(result.targetChanged).toBe(true);
+    expect(result.requiresCredentialRefresh).toBe(false);
+    expect(result.metadata.api_key).toBe('encrypted-new-key');
+  });
+
+  it('allows target changes when auth is explicitly removed', () => {
+    const incoming: ActionMetadata = {
+      domain: 'https://api.example.com',
+      raw_spec: specFor('https://api.example.com/v2'),
+      auth: {
+        type: AuthTypeEnum.None,
+      },
+    };
+
+    const result = mergeActionMetadataForUpdate({
+      storedMetadata: serviceMetadata(),
+      incomingMetadata: incoming,
+    });
+
+    expect(result.targetChanged).toBe(true);
+    expect(result.requiresCredentialRefresh).toBe(false);
+    expect(result.metadata.api_key).toBeUndefined();
+  });
+
+  it('requires fresh OAuth client credentials when OAuth endpoints change', () => {
+    const storedMetadata: ActionMetadata = {
+      domain: 'https://api.example.com',
+      raw_spec: specFor('https://api.example.com/v1'),
+      oauth_client_id: 'encrypted-client-id',
+      oauth_client_secret: 'encrypted-client-secret',
+      auth: {
+        type: AuthTypeEnum.OAuth,
+        authorization_url: 'https://auth.example.com/authorize',
+        client_url: 'https://auth.example.com/token',
+        scope: 'read',
+        token_exchange_method: TokenExchangeMethodEnum.DefaultPost,
+      },
+    };
+    const incomingMetadata: ActionMetadata = {
+      auth: {
+        type: AuthTypeEnum.OAuth,
+        authorization_url: 'https://evil.example/authorize',
+        client_url: 'https://evil.example/token',
+        scope: 'read',
+        token_exchange_method: TokenExchangeMethodEnum.DefaultPost,
+      },
+    };
+
+    const result = mergeActionMetadataForUpdate({
+      storedMetadata,
+      incomingMetadata,
+    });
+
+    expect(result.targetChanged).toBe(true);
+    expect(result.requiresCredentialRefresh).toBe(true);
+    expect(result.metadata.oauth_client_id).toBeUndefined();
+    expect(result.metadata.oauth_client_secret).toBeUndefined();
+  });
+});
diff --git a/packages/api/src/actions/credentials.ts b/packages/api/src/actions/credentials.ts
new file mode 100644
index 0000000000..ad53d21c8b
--- /dev/null
+++ b/packages/api/src/actions/credentials.ts
@@ -0,0 +1,194 @@
+import { AuthTypeEnum, validateAndParseOpenAPISpec } from 'librechat-data-provider';
+import type { ActionAuth, ActionMetadata } from 'librechat-data-provider';
+
+const authBoundaryFields: Array<keyof ActionAuth> = [
+  'type',
+  'authorization_type',
+  'custom_auth_header',
+  'authorization_url',
+  'client_url',
+  'scope',
+  'token_exchange_method',
+];
+
+export type ActionMetadataUpdateResult = {
+  metadata: ActionMetadata;
+  targetChanged: boolean;
+  requiresCredentialRefresh: boolean;
+};
+
+export type ActionMetadataUpdateParams = {
+  storedMetadata: ActionMetadata;
+  incomingMetadata: ActionMetadata;
+};
+
+function hasOwn<T extends object, K extends PropertyKey>(
+  obj: T | null | undefined,
+  key: K,
+): obj is T & Record<K, unknown> {
+  return obj != null && Object.prototype.hasOwnProperty.call(obj, key);
+}
+
+function hasValue(value: string | undefined): boolean {
+  return typeof value === 'string' && value.length > 0;
+}
+
+function normalizeUrlTarget(value: string | undefined): string {
+  if (!value) {
+    return '';
+  }
+
+  try {
+    const url = new URL(value);
+    const pathname = url.pathname.replace(/\/+$/, '');
+    return `${url.protocol}//${url.host.toLowerCase()}${pathname}${url.search}`;
+  } catch {
+    return value.trim().toLowerCase().replace(/\/+$/, '');
+  }
+}
+
+function normalizeDomainTarget(value: string | undefined): string {
+  if (!value) {
+    return '';
+  }
+
+  const urlValue = value.includes('://') ? value : `https://${value}`;
+  try {
+    const url = new URL(urlValue);
+    return `${url.protocol}//${url.host.toLowerCase()}`;
+  } catch {
+    return value.trim().toLowerCase().replace(/\/+$/, '');
+  }
+}
+
+function getSpecServerTarget(rawSpec: string | undefined): string {
+  if (!rawSpec) {
+    return '';
+  }
+
+  const result = validateAndParseOpenAPISpec(rawSpec);
+  return normalizeUrlTarget(result.serverUrl);
+}
+
+function didDomainChange(
+  storedMetadata: ActionMetadata,
+  incomingMetadata: ActionMetadata,
+): boolean {
+  if (!hasOwn(incomingMetadata, 'domain')) {
+    return false;
+  }
+
+  return (
+    normalizeDomainTarget(storedMetadata.domain) !== normalizeDomainTarget(incomingMetadata.domain)
+  );
+}
+
+function didSpecServerChange(
+  storedMetadata: ActionMetadata,
+  incomingMetadata: ActionMetadata,
+): boolean {
+  if (!hasOwn(incomingMetadata, 'raw_spec')) {
+    return false;
+  }
+
+  return (
+    getSpecServerTarget(storedMetadata.raw_spec) !== getSpecServerTarget(incomingMetadata.raw_spec)
+  );
+}
+
+function didAuthBoundaryChange(
+  storedMetadata: ActionMetadata,
+  incomingMetadata: ActionMetadata,
+): boolean {
+  if (!hasOwn(incomingMetadata, 'auth')) {
+    return false;
+  }
+
+  return authBoundaryFields.some(
+    (field) => storedMetadata.auth?.[field] !== incomingMetadata.auth?.[field],
+  );
+}
+
+function getTargetChanged(
+  storedMetadata: ActionMetadata,
+  incomingMetadata: ActionMetadata,
+): boolean {
+  return (
+    didDomainChange(storedMetadata, incomingMetadata) ||
+    didSpecServerChange(storedMetadata, incomingMetadata) ||
+    didAuthBoundaryChange(storedMetadata, incomingMetadata)
+  );
+}
+
+function getNextAuthType(
+  storedMetadata: ActionMetadata,
+  incomingMetadata: ActionMetadata,
+): AuthTypeEnum | undefined {
+  return incomingMetadata.auth?.type ?? storedMetadata.auth?.type;
+}
+
+function requiresCredentialRefresh(
+  storedMetadata: ActionMetadata,
+  incomingMetadata: ActionMetadata,
+): boolean {
+  const authType = getNextAuthType(storedMetadata, incomingMetadata);
+
+  if (authType === AuthTypeEnum.ServiceHttp) {
+    return hasValue(storedMetadata.api_key) && !hasValue(incomingMetadata.api_key);
+  }
+
+  if (authType === AuthTypeEnum.OAuth) {
+    return (
+      (hasValue(storedMetadata.oauth_client_id) && !hasValue(incomingMetadata.oauth_client_id)) ||
+      (hasValue(storedMetadata.oauth_client_secret) &&
+        !hasValue(incomingMetadata.oauth_client_secret))
+    );
+  }
+
+  return false;
+}
+
+function removeUnsubmittedCredentials(
+  metadata: ActionMetadata,
+  incomingMetadata: ActionMetadata,
+): ActionMetadata {
+  const sanitized = { ...metadata };
+
+  if (!hasValue(incomingMetadata.api_key)) {
+    delete sanitized.api_key;
+  }
+
+  if (!hasValue(incomingMetadata.oauth_client_id)) {
+    delete sanitized.oauth_client_id;
+  }
+
+  if (!hasValue(incomingMetadata.oauth_client_secret)) {
+    delete sanitized.oauth_client_secret;
+  }
+
+  return sanitized;
+}
+
+/**
+ * Preserves saved credentials only while an Action continues to point at the
+ * same request/auth boundary. A changed domain, OpenAPI server URL, or auth
+ * endpoint must come with fresh credentials or explicitly remove auth.
+ */
+export function mergeActionMetadataForUpdate({
+  storedMetadata,
+  incomingMetadata,
+}: ActionMetadataUpdateParams): ActionMetadataUpdateResult {
+  const targetChanged = getTargetChanged(storedMetadata, incomingMetadata);
+  const refreshRequired = targetChanged
+    ? requiresCredentialRefresh(storedMetadata, incomingMetadata)
+    : false;
+  const mergedMetadata = { ...storedMetadata, ...incomingMetadata };
+
+  return {
+    targetChanged,
+    requiresCredentialRefresh: refreshRequired,
+    metadata: targetChanged
+      ? removeUnsubmittedCredentials(mergedMetadata, incomingMetadata)
+      : mergedMetadata,
+  };
+}
diff --git a/packages/api/src/actions/index.ts b/packages/api/src/actions/index.ts
new file mode 100644
index 0000000000..bd6bb74bd5
--- /dev/null
+++ b/packages/api/src/actions/index.ts
@@ -0,0 +1,3 @@
+export * from './credentials';
+export * from './tools';
+export * from './update';
diff --git a/packages/api/src/actions/tools.spec.ts b/packages/api/src/actions/tools.spec.ts
new file mode 100644
index 0000000000..2b4747de64
--- /dev/null
+++ b/packages/api/src/actions/tools.spec.ts
@@ -0,0 +1,92 @@
+jest.mock(
+  'librechat-data-provider',
+  () => ({
+    actionDelimiter: '_action_',
+    validateAndParseOpenAPISpec: (specString: string) => {
+      const spec = JSON.parse(specString) as { paths?: Record<string, unknown> };
+      return {
+        status: true,
+        message: 'OpenAPI spec is valid.',
+        spec,
+        serverUrl: 'https://api.example.com',
+      };
+    },
+  }),
+  { virtual: true },
+);
+
+import { mergeAgentActionTools } from './tools';
+
+const specFor = (operationId: string): string =>
+  JSON.stringify({
+    openapi: '3.0.0',
+    info: { title: 'Action API', version: '1.0.0' },
+    servers: [{ url: 'https://api.example.com' }],
+    paths: {
+      '/items': {
+        get: {
+          operationId,
+          responses: { 200: { description: 'OK' } },
+        },
+      },
+    },
+  });
+
+const toolFor = (name: string) => ({
+  function: {
+    name,
+  },
+});
+
+describe('mergeAgentActionTools', () => {
+  it('preserves other action tools that share the previous domain', () => {
+    const result = mergeAgentActionTools({
+      existingTools: [
+        'listItems_action_shared_domain',
+        'echoMessage_action_shared_domain',
+        'echoMessage_action_legacy_domain',
+      ],
+      incomingFunctions: [toolFor('echoMessage')],
+      encodedDomain: 'new_domain',
+      actionId: 'action-a',
+      requestedActionId: 'action-a',
+      previousEncodedDomain: 'shared_domain',
+      previousLegacyDomain: 'legacy_domain',
+      previousRawSpec: specFor('echoMessage'),
+    });
+
+    expect(result).toEqual(['listItems_action_shared_domain', 'echoMessage_action_new_domain']);
+  });
+
+  it('removes previous operation names when an action function is renamed', () => {
+    const result = mergeAgentActionTools({
+      existingTools: ['oldName_action_shared_domain', 'unrelated_action_shared_domain'],
+      incomingFunctions: [toolFor('newName')],
+      encodedDomain: 'shared_domain',
+      actionId: 'action-a',
+      requestedActionId: 'action-a',
+      previousEncodedDomain: 'shared_domain',
+      previousRawSpec: specFor('oldName'),
+    });
+
+    expect(result).toEqual(['unrelated_action_shared_domain', 'newName_action_shared_domain']);
+  });
+
+  it('removes legacy action-id keyed entries without dropping unrelated tools', () => {
+    const result = mergeAgentActionTools({
+      existingTools: [
+        'legacy-action-a',
+        'listItems_action_shared_domain',
+        'echoMessage_action_shared_domain',
+      ],
+      incomingFunctions: [toolFor('echoMessage')],
+      encodedDomain: 'shared_domain',
+      actionId: 'action-a',
+      requestedActionId: 'action-a',
+      previousEncodedDomain: 'shared_domain',
+      previousRawSpec: specFor('echoMessage'),
+    });
+
+    expect(result).toEqual(['listItems_action_shared_domain', 'echoMessage_action_shared_domain']);
+  });
+});
diff --git a/packages/api/src/actions/tools.ts b/packages/api/src/actions/tools.ts
new file mode 100644
index 0000000000..2647d5cde5
--- /dev/null
+++ b/packages/api/src/actions/tools.ts
@@ -0,0 +1,127 @@
+import { actionDelimiter, validateAndParseOpenAPISpec } from 'librechat-data-provider';
+
+export type ActionToolLike = {
+  function?: {
+    name?: string;
+  };
+};
+
+export type MergeAgentActionToolsParams = {
+  existingTools: string[];
+  incomingFunctions: ActionToolLike[];
+  encodedDomain: string;
+  actionId: string;
+  requestedActionId?: string;
+  legacyDomain?: string;
+  previousEncodedDomain?: string;
+  previousLegacyDomain?: string;
+  previousRawSpec?: string;
+};
+
+const httpMethods = new Set(['get', 'put', 'post', 'delete', 'options', 'head', 'patch', 'trace']);
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null;
+}
+
+function sanitizeOperationId(input: string): string {
+  return input.replace(/[^a-zA-Z0-9_-]/g, '');
+}
+
+function getFunctionNames(functions: ActionToolLike[]): string[] {
+  const names = new Set<string>();
+
+  for (const tool of functions) {
+    const name = tool.function?.name;
+    if (typeof name === 'string' && name.length > 0) {
+      names.add(name);
+    }
+  }
+
+  return [...names];
+}
+
+function getSpecOperationNames(rawSpec?: string): string[] {
+  if (!rawSpec) {
+    return [];
+  }
+
+  const result = validateAndParseOpenAPISpec(rawSpec);
+  if (!result.status || !isRecord(result.spec?.paths)) {
+    return [];
+  }
+
+  const names = new Set<string>();
+  for (const [path, methods] of Object.entries(result.spec.paths)) {
+    if (!isRecord(methods)) {
+      continue;
+    }
+
+    for (const [method, operation] of Object.entries(methods)) {
+      if (!httpMethods.has(method.toLowerCase()) || !isRecord(operation)) {
+        continue;
+      }
+
+      const operationId = operation.operationId;
+      names.add(
+        typeof operationId === 'string' && operationId.length > 0
+          ? operationId
+          : sanitizeOperationId(`${method}_${path}`),
+      );
+    }
+  }
+
+  return [...names];
+}
+
+function getUniqueValues(values: Array<string | undefined>): string[] {
+  return [...new Set(values.filter((value): value is string => !!value))];
+}
+
+export function mergeAgentActionTools({
+  existingTools,
+  incomingFunctions,
+  encodedDomain,
+  actionId,
+  requestedActionId,
+  legacyDomain,
+  previousEncodedDomain,
+  previousLegacyDomain,
+  previousRawSpec,
+}: MergeAgentActionToolsParams): string[] {
+  const incomingNames = getFunctionNames(incomingFunctions);
+  const domainsToReplace = getUniqueValues([
+    encodedDomain,
+    legacyDomain,
+    previousEncodedDomain,
+    previousLegacyDomain,
+  ]);
+  const namesToReplace = getUniqueValues([
+    ...incomingNames,
+    ...getSpecOperationNames(previousRawSpec),
+  ]);
+  const toolsToReplace = new Set<string>();
+
+  for (const name of namesToReplace) {
+    for (const domain of domainsToReplace) {
+      toolsToReplace.add(`${name}${actionDelimiter}${domain}`);
+    }
+  }
+
+  const actionIdsToReplace = getUniqueValues([actionId, requestedActionId]);
+  const retainedTools = existingTools.filter((tool) => {
+    if (!tool) {
+      return false;
+    }
+
+    if (toolsToReplace.has(tool)) {
+      return false;
+    }
+
+    return !actionIdsToReplace.some((id) => tool.includes(id));
+  });
+
+  return retainedTools.concat(
+    incomingNames.map((name) => `${name}${actionDelimiter}${encodedDomain}`),
+  );
+}
diff --git a/packages/api/src/actions/update.spec.ts b/packages/api/src/actions/update.spec.ts
new file mode 100644
index 0000000000..ed356100af
--- /dev/null
+++ b/packages/api/src/actions/update.spec.ts
@@ -0,0 +1,152 @@
+jest.mock(
+  'librechat-data-provider',
+  () => ({
+    actionDelimiter: '_action_',
+    actionDomainSeparator: '---',
+    Constants: {
+      ENCODED_DOMAIN_LENGTH: 64,
+    },
+    AuthTypeEnum: {
+      ServiceHttp: 'service_http',
+      OAuth: 'oauth',
+      None: 'none',
+    },
+    AuthorizationTypeEnum: {
+      Bearer: 'bearer',
+    },
+    validateAndParseOpenAPISpec: (specString: string) => {
+      const spec = JSON.parse(specString) as { servers?: Array<{ url?: string }> };
+      return {
+        status: true,
+        message: 'OpenAPI spec is valid.',
+        spec,
+        serverUrl: spec.servers?.[0]?.url,
+      };
+    },
+  }),
+  { virtual: true },
+);
+
+import { AuthTypeEnum, AuthorizationTypeEnum } from 'librechat-data-provider';
+import type { ActionMetadata } from 'librechat-data-provider';
+import {
+  buildActionOAuthTokenDeleteQueries,
+  legacyActionDomainEncode,
+  planAgentActionUpdate,
+} from './update';
+
+const specFor = (serverUrl: string, operationId = 'echoMessage'): string =>
+  JSON.stringify({
+    openapi: '3.0.0',
+    info: { title: 'Action API', version: '1.0.0' },
+    servers: [{ url: serverUrl }],
+    paths: {
+      '/echo': {
+        get: {
+          operationId,
+          responses: { 200: { description: 'OK' } },
+        },
+      },
+    },
+  });
+
+const toolFor = (name: string) => ({
+  function: {
+    name,
+  },
+});
+
+const storedServiceMetadata: ActionMetadata = {
+  domain: 'https://api.example.com',
+  raw_spec: specFor('https://api.example.com/v1'),
+  api_key: 'encrypted-owner-key',
+  auth: {
+    type: AuthTypeEnum.ServiceHttp,
+    authorization_type: AuthorizationTypeEnum.Bearer,
+  },
+};
+
+describe('planAgentActionUpdate', () => {
+  it('requires refreshed credentials when an existing target changes without new credentials', () => {
+    const result = planAgentActionUpdate({
+      agentActions: ['api---example---com_action_action-1'],
+      agentTools: ['echoMessage_action_api---example---com'],
+      incomingFunctions: [toolFor('echoMessage')],
+      incomingMetadata: {
+        domain: 'https://other.example.com',
+        raw_spec: specFor('https://other.example.com/v1'),
+      },
+      actionId: 'action-1',
+      requestedActionId: 'action-1',
+      encodedDomain: 'other---example---com',
+      legacyDomain: legacyActionDomainEncode('https://other.example.com'),
+      previousLegacyDomain: legacyActionDomainEncode('https://api.example.com'),
+      storedAction: {
+        metadata: storedServiceMetadata,
+      },
+    });
+
+    expect(result.requiresCredentialRefresh).toBe(true);
+    expect(result.targetChanged).toBe(true);
+    expect(result.deleteOAuthTokens).toBe(true);
+    expect(result.metadata.api_key).toBeUndefined();
+  });
+
+  it('plans a stable-id target update while preserving unrelated same-domain tools', () => {
+    const result = planAgentActionUpdate({
+      agentActions: ['api---example---com_action_action-1', 'api---example---com_action_action-2'],
+      agentTools: [
+        'echoMessage_action_api---example---com',
+        'listItems_action_api---example---com',
+      ],
+      incomingFunctions: [toolFor('echoMessage')],
+      incomingMetadata: {
+        domain: 'https://other.example.com',
+        raw_spec: specFor('https://other.example.com/v1'),
+        api_key: 'encrypted-new-key',
+        auth: {
+          type: AuthTypeEnum.ServiceHttp,
+          authorization_type: AuthorizationTypeEnum.Bearer,
+        },
+      },
+      actionId: 'action-1',
+      requestedActionId: 'action-1',
+      encodedDomain: 'other---example---com',
+      legacyDomain: legacyActionDomainEncode('https://other.example.com'),
+      previousLegacyDomain: legacyActionDomainEncode('https://api.example.com'),
+      storedAction: {
+        metadata: storedServiceMetadata,
+      },
+    });
+
+    expect(result.requiresCredentialRefresh).toBe(false);
+    expect(result.actionId).toBe('action-1');
+    expect(result.deleteOAuthTokens).toBe(true);
+    expect(result.actions).toEqual([
+      'api---example---com_action_action-2',
+      'other---example---com_action_action-1',
+    ]);
+    expect(result.tools).toEqual([
+      'listItems_action_api---example---com',
+      'echoMessage_action_other---example---com',
+    ]);
+  });
+});
+
+describe('buildActionOAuthTokenDeleteQueries', () => {
+  it('builds escaped access and refresh token identifier queries', () => {
+    const [accessQuery, refreshQuery] = buildActionOAuthTokenDeleteQueries('action.1');
+
+    expect(accessQuery).toEqual({
+      type: 'oauth',
+      identifier: expect.any(RegExp),
+    });
+    expect(refreshQuery).toEqual({
+      type: 'oauth_refresh',
+      identifier: expect.any(RegExp),
+    });
+    expect(accessQuery.identifier.test('user-1:action.1')).toBe(true);
+    expect(accessQuery.identifier.test('user-1:actionx1')).toBe(false);
+    expect(refreshQuery.identifier.test('user-1:action.1:refresh')).toBe(true);
+  });
+});
diff --git a/packages/api/src/actions/update.ts b/packages/api/src/actions/update.ts
new file mode 100644
index 0000000000..03bb3ba861
--- /dev/null
+++ b/packages/api/src/actions/update.ts
@@ -0,0 +1,163 @@
+import { Constants, actionDelimiter, actionDomainSeparator } from 'librechat-data-provider';
+import type { ActionMetadata } from 'librechat-data-provider';
+import type { ActionToolLike } from './tools';
+import { mergeActionMetadataForUpdate } from './credentials';
+import { mergeAgentActionTools } from './tools';
+
+export const ACTION_CREDENTIAL_REFRESH_MESSAGE =
+  'Action credentials must be re-entered when changing the domain, OpenAPI server URL, or authentication settings';
+
+type StoredActionForUpdate = {
+  metadata?: ActionMetadata | null;
+};
+
+export type PlanAgentActionUpdateParams = {
+  agentActions: string[];
+  agentTools: string[];
+  incomingFunctions: ActionToolLike[];
+  incomingMetadata: ActionMetadata;
+  actionId: string;
+  requestedActionId?: string;
+  encodedDomain: string;
+  legacyDomain?: string;
+  previousLegacyDomain?: string;
+  storedAction?: StoredActionForUpdate | null;
+};
+
+export type PlannedAgentActionUpdate = {
+  actionId: string;
+  metadata: ActionMetadata;
+  actions: string[];
+  tools: string[];
+  targetChanged: boolean;
+  requiresCredentialRefresh: boolean;
+  deleteOAuthTokens: boolean;
+};
+
+export type ActionOAuthTokenDeleteQuery = {
+  type: 'oauth' | 'oauth_refresh';
+  identifier: RegExp;
+};
+
+function escapeRegExp(value: string): string {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+function getUpdatedAgentActionRefs({
+  agentActions,
+  actionId,
+  requestedActionId,
+  encodedDomain,
+}: Pick<
+  PlanAgentActionUpdateParams,
+  'agentActions' | 'actionId' | 'requestedActionId' | 'encodedDomain'
+>): {
+  actions: string[];
+  previousEncodedDomain?: string;
+} {
+  const actions: string[] = [];
+  let previousEncodedDomain: string | undefined;
+
+  for (const action of agentActions) {
+    const [actionDomain, currentActionId] = action.split(actionDelimiter);
+    if (
+      (requestedActionId && currentActionId === requestedActionId) ||
+      currentActionId === actionId
+    ) {
+      previousEncodedDomain = actionDomain;
+      continue;
+    }
+
+    actions.push(action);
+  }
+
+  actions.push(`${encodedDomain}${actionDelimiter}${actionId}`);
+
+  return {
+    actions,
+    previousEncodedDomain,
+  };
+}
+
+export function legacyActionDomainEncode(domain?: string): string {
+  if (!domain) {
+    return '';
+  }
+
+  if (domain.length <= Constants.ENCODED_DOMAIN_LENGTH) {
+    return domain.replace(/\./g, actionDomainSeparator);
+  }
+
+  const modifiedDomain = Buffer.from(domain).toString('base64');
+  return modifiedDomain.substring(0, Constants.ENCODED_DOMAIN_LENGTH);
+}
+
+export function buildActionOAuthTokenDeleteQueries(
+  actionId: string,
+): ActionOAuthTokenDeleteQuery[] {
+  const escapedActionId = escapeRegExp(actionId);
+
+  return [
+    {
+      type: 'oauth',
+      identifier: new RegExp(`^[^:]+:${escapedActionId}$`),
+    },
+    {
+      type: 'oauth_refresh',
+      identifier: new RegExp(`^[^:]+:${escapedActionId}:refresh$`),
+    },
+  ];
+}
+
+export function planAgentActionUpdate({
+  agentActions,
+  agentTools,
+  incomingFunctions,
+  incomingMetadata,
+  actionId,
+  requestedActionId,
+  encodedDomain,
+  legacyDomain,
+  previousLegacyDomain,
+  storedAction,
+}: PlanAgentActionUpdateParams): PlannedAgentActionUpdate {
+  const metadataUpdate = storedAction
+    ? mergeActionMetadataForUpdate({
+        storedMetadata: storedAction.metadata ?? {},
+        incomingMetadata,
+      })
+    : {
+        metadata: incomingMetadata,
+        targetChanged: false,
+        requiresCredentialRefresh: false,
+      };
+
+  const { actions, previousEncodedDomain } = getUpdatedAgentActionRefs({
+    agentActions,
+    actionId,
+    requestedActionId,
+    encodedDomain,
+  });
+
+  const tools = mergeAgentActionTools({
+    existingTools: agentTools,
+    incomingFunctions,
+    encodedDomain,
+    actionId,
+    requestedActionId,
+    legacyDomain,
+    previousEncodedDomain,
+    previousLegacyDomain,
+    previousRawSpec: storedAction?.metadata?.raw_spec,
+  });
+
+  return {
+    actionId,
+    actions,
+    tools,
+    metadata: metadataUpdate.metadata,
+    targetChanged: metadataUpdate.targetChanged,
+    requiresCredentialRefresh: metadataUpdate.requiresCredentialRefresh,
+    deleteOAuthTokens: Boolean(metadataUpdate.targetChanged && requestedActionId),
+  };
+}
diff --git a/packages/api/src/index.ts b/packages/api/src/index.ts
index 130b563839..49e4ff50d3 100644
--- a/packages/api/src/index.ts
+++ b/packages/api/src/index.ts
@@ -39,6 +39,8 @@ export * from './memory';
 export * from './modelSpecs';
 /* Agents */
 export * from './agents';
+/* Actions */
+export * from './actions';
 /* Prompts */
 export * from './prompts';
 /* Projects */
diff --git a/packages/data-schemas/src/methods/token.spec.ts b/packages/data-schemas/src/methods/token.spec.ts
index 9508784fea..7e7c44c185 100644
--- a/packages/data-schemas/src/methods/token.spec.ts
+++ b/packages/data-schemas/src/methods/token.spec.ts
@@ -580,6 +580,38 @@ describe('Token Methods - Detailed Tests', () => {
       expect(remainingTokens.find((t) => t.identifier === 'oauth-identifier-456')).toBeUndefined();
     });
 
+    test('should delete tokens matching an identifier pattern', async () => {
+      await Token.create([
+        {
+          token: 'action-access-token',
+          userId: oauthUserId,
+          type: 'oauth',
+          identifier: `${oauthUserId.toString()}:action-1`,
+          createdAt: new Date(),
+          expiresAt: new Date(Date.now() + 3600000),
+        },
+        {
+          token: 'other-action-token',
+          userId: oauthUserId,
+          type: 'oauth',
+          identifier: `${oauthUserId.toString()}:action-2`,
+          createdAt: new Date(),
+          expiresAt: new Date(Date.now() + 3600000),
+        },
+      ]);
+
+      const result = await methods.deleteTokens({
+        type: 'oauth',
+        identifier: /^[^:]+:action-1$/,
+      });
+
+      expect(result.deletedCount).toBe(1);
+
+      const remaining = await Token.find({ userId: oauthUserId, type: 'oauth' });
+      expect(remaining).toHaveLength(1);
+      expect(remaining[0].identifier).toBe(`${oauthUserId.toString()}:action-2`);
+    });
+
     test('should not delete tokens when undefined fields are passed', async () => {
       // This is the critical test case for the bug fix
       const result = await methods.deleteTokens({
diff --git a/packages/data-schemas/src/types/token.ts b/packages/data-schemas/src/types/token.ts
index bc61f9f136..889f1768a3 100644
--- a/packages/data-schemas/src/types/token.ts
+++ b/packages/data-schemas/src/types/token.ts
@@ -27,7 +27,7 @@ export interface TokenQuery {
   token?: string;
   email?: string | null;
   type?: string | null;
-  identifier?: string | null;
+  identifier?: string | RegExp | null;
 }
 
 export interface TokenUpdateData {