ComposioHQ/composio · warning · ComposioFileUploadAbortedError

File upload was aborted because beforeFileUpload returned fa

Error message

File upload was aborted because beforeFileUpload returned false.

What it means

runBeforeFileUpload invokes the user-supplied beforeFileUpload hook; when the hook returns false, the SDK aborts the upload with ComposioFileUploadAbortedError. This is a deliberate, policy-driven abort for local paths/URLs.

Source

Thrown at ts/packages/core/src/utils/modifiers/FileToolModifier.node.ts:91

  if (isEmptyFileValue(value)) return DELETE_VALUE;
  // Upload only if the runtime value is a string (i.e., a local path) or blob
  if (typeof value !== 'string' && !(value instanceof File)) return value;

  const runBeforeFileUpload = async (
    path: string,
    source: 'path' | 'url' | 'file'
  ): Promise<string> => {
    if (!ctx.beforeFileUpload) {
      return path;
    }
    const out = await ctx.beforeFileUpload({
      path,
      source,
      toolSlug: ctx.toolSlug,
      toolkitSlug: ctx.toolkitSlug,
    });
    if (out === false) {
      throw new ComposioFileUploadAbortedError(
        'File upload was aborted because beforeFileUpload returned false.'
      );
    }
    return out;
  };

  if (typeof value === 'string') {
    // Match the URL/local-path split used downstream in
    // getFileDataAfterUploadingToS3 so the hook sees the same categorisation.
    const source = isHttpUrl(value) ? 'url' : 'path';
    const pathOrUrl = await runBeforeFileUpload(value, source);
    logger.debug(`Uploading file "${pathOrUrl}"`);
    return getFileDataAfterUploadingToS3(pathOrUrl, {
      toolSlug: ctx.toolSlug,
      toolkitSlug: ctx.toolkitSlug,
      client: ctx.client,
      sensitiveFileUploadProtection: ctx.sensitiveFileUploadProtection,
      fileUploadPathDenySegments: ctx.fileUploadPathDenySegments,

View on GitHub (pinned to 64b1b85502)

Solutions

1. This is expected behavior: catch ComposioFileUploadAbortedError and handle the rejection gracefully.
2. Adjust the hook's condition if legitimate files are being rejected.
3. Log path/source in the hook to see why it returned false.

Example fix

// before
beforeFileUpload: ({ path }) => path.startsWith('/data'),
// after
beforeFileUpload: ({ path }) => path.startsWith('/data') || path.startsWith('/tmp/uploads'),

const isUploadAborted = (e: unknown): e is ComposioFileUploadAbortedError =>
  e instanceof ComposioFileUploadAbortedError;

try { await tool.execute(args); }
catch (e) { if (isUploadAborted(e)) { /* policy rejection, skip */ return; } throw e; }

When it happens

Trigger: Configuring a FileToolModifier with beforeFileUpload that returns false for a given path/url (e.g. allowlist mismatch, size check failed) and then executing the tool with that path.

Common situations: Allowlisting specific directories, blocking file types, or content checks in the hook — the throw is your own policy firing, not a bug.

Related errors

• Failed to fetch file: ${response.statusText}
• Invalid file type
• Either path or blob must be provided
• maxBytes must be a non-negative safe integer
• File upload was aborted because before_file_upload returned

AI-assisted analysis of ComposioHQ/composio@64b1b85502 (2026-08-28). Data as JSON: /api/errors/c5ba371ae7f95dfc. Report an issue: GitHub.