diff --git a/api/server/services/Files/provision.js b/api/server/services/Files/provision.js
index 6371a54203..f89d6e293b 100644
--- a/api/server/services/Files/provision.js
+++ b/api/server/services/Files/provision.js
@@ -20,6 +20,34 @@ const { getStrategyFunctions } = require('./strategies');
 
 const axios = createAxiosInstance();
 
+/* Sources whose `getDownloadStream` takes `(req, filepath)` and returns a readable.
+ * Others diverge: `openai` takes `(file_id, client)` and `execute_code` takes
+ * `(fileIdentifier, identity, req)` returning an Axios response, so calling them
+ * through this contract fails. An allowlist keeps an unfamiliar source skipped
+ * rather than mis-invoked. */
+const STORAGE_STREAM_SOURCES = new Set([
+  FileSources.local,
+  FileSources.s3,
+  FileSources.cloudfront,
+  FileSources.azure_blob,
+  FileSources.firebase,
+]);
+
+/** Resolves a storage download stream, or null when the source uses a different contract. */
+async function getStorageStream(file, req) {
+  if (!STORAGE_STREAM_SOURCES.has(file.source)) {
+    logger.warn(
+      `[provision] Cannot stream "${file.filename}" (${file.file_id}) from source "${file.source}": unsupported download contract`,
+    );
+    return null;
+  }
+  const { getDownloadStream } = getStrategyFunctions(file.source);
+  if (!getDownloadStream) {
+    return null;
+  }
+  return await getDownloadStream(req, file.filepath);
+}
+
 /** Composes code-API auth: legacy X-API-Key when configured, plus JWT bearer when enabled. */
 async function buildCodeApiHeaders({ apiKey, req }) {
   return {
@@ -82,16 +110,14 @@ async function loadCodeApiKey(userId) {
  *   Merged pointers plus the deferred DB update
  */
 async function provisionToCodeEnv({ req, file, entity_id }) {
-  const { getDownloadStream } = getStrategyFunctions(file.source);
-  if (!getDownloadStream) {
+  const { handleFileUpload: uploadCodeEnvFile } = getStrategyFunctions(FileSources.execute_code);
+  const stream = await getStorageStream(file, req);
+  if (!stream) {
     throw new Error(
       `Cannot provision file "${file.filename}" to code env: storage source "${file.source}" does not support download streams`,
     );
   }
 
-  const { handleFileUpload: uploadCodeEnvFile } = getStrategyFunctions(FileSources.execute_code);
-  const stream = await getDownloadStream(req, file.filepath);
-
   const kind = entity_id ? 'agent' : 'user';
   const id = entity_id ?? req.user.id;
 
@@ -147,13 +173,12 @@ async function provisionToVectorDB({ req, file, entity_id, existingStream }) {
   try {
     let stream = existingStream;
     if (!stream) {
-      const { getDownloadStream } = getStrategyFunctions(file.source);
-      if (!getDownloadStream) {
+      stream = await getStorageStream(file, req);
+      if (!stream) {
         throw new Error(
           `Cannot provision file "${file.filename}" to vector DB: storage source "${file.source}" does not support download streams`,
         );
       }
-      stream = await getDownloadStream(req, file.filepath);
     }
 
     // uploadVectors expects a file-like object with a `path` property for fs.createReadStream.
diff --git a/api/server/services/Files/provision.spec.js b/api/server/services/Files/provision.spec.js
index 4e6aa03d6e..9cecd0f58c 100644
--- a/api/server/services/Files/provision.spec.js
+++ b/api/server/services/Files/provision.spec.js
@@ -157,6 +157,26 @@ describe('provisionToCodeEnv', () => {
     expect(result.referenceSet.codeEnvRefs.default.executionProfile).toBe('default');
   });
 
+  it('refuses sources whose download contract differs instead of mis-invoking them', async () => {
+    const uploadCodeEnvFile = jest.fn();
+    setupStrategies(uploadCodeEnvFile);
+
+    await expect(
+      provisionToCodeEnv({
+        req: { user: { id: 'u1' } },
+        file: {
+          file_id: 'f-openai',
+          filename: 'doc.pdf',
+          type: 'application/pdf',
+          source: 'openai',
+          filepath: '/x/doc.pdf',
+          metadata: {},
+        },
+      }),
+    ).rejects.toThrow(/does not support download streams/);
+    expect(uploadCodeEnvFile).not.toHaveBeenCalled();
+  });
+
   it('keeps filenames untouched when the extension already matches or the file is not an image', async () => {
     const uploadCodeEnvFile = jest
       .fn()