ComposioHQ/composio · error · Error

Invalid file type

Error message

Invalid file type

What it means

readFile dispatches on input type: File objects, http(s) URLs, and local paths are supported. Anything else falls through to throw 'Invalid file type'.

Source

Thrown at ts/packages/core/src/utils/fileUtils.node.ts:286

const readFile = async (
  file: File | string,
  signal?: AbortSignal
): Promise<{ fileName: string; content: string; mimeType: string }> => {
  if (file instanceof File) {
    const content = await file.arrayBuffer();
    return {
      fileName: file.name,
      content: uint8ArrayToBase64(new Uint8Array(content)),
      mimeType: file.type,
    };
  } else if (typeof file === 'string') {
    if (isHttpUrl(file)) {
      return await readFileContentFromURL(file, signal);
    } else {
      return await readFileContent(file);
    }
  }
  throw new Error('Invalid file type');
};

export const getFileDataAfterUploadingToS3 = async (
  file: File | string,
  {
    toolSlug,
    toolkitSlug,
    client,
    sensitiveFileUploadProtection,
    fileUploadPathDenySegments,
    fileUploadAllowlist,
    signal,
  }: GetFileDataAfterUploadingToS3Options
): Promise<FileUploadData> => {
  if (!file) {
    throw new Error('Either path or blob must be provided');
  }

View on GitHub (pinned to 64b1b85502)

Solutions

1. Wrap binary data in a File (new File([buffer], name)).
2. Use an http(s) URL or local filesystem path string.
3. Narrow the input type before calling: typeof file === 'string' || file instanceof File.

Example fix

// before
await readFile(new Blob([bytes]));
// after
await readFile(new File([bytes], 'data.bin'));

const isFileInput = (f: unknown): f is File | string =>
  typeof f === 'string' || (typeof File !== 'undefined' && f instanceof File);

const isFileInput = (f: unknown): f is File | string =>
  typeof f === 'string' || f instanceof File;

When it happens

Trigger: Passing a Blob (not File), a plain object, a number, or a non-http protocol string (ftp://, file://) to readFile/getFileDataAfterUploadingToS3.

Common situations: Cross-SDK porting where Python accepted plain blobs, or passing Buffer/Uint8Array directly instead of wrapping in a File.

Understand the failure class

Background: Invalid argument type errors: "must be of type string", "expected X, got Y", and ERR_INVALID_ARG_TYPE explained — this error's family across 15 libraries.

Related errors

• Either path or blob must be provided
• maxBytes must be a non-negative safe integer
• experimental_subAgent() target must be "claude", "codex", or
• Unsupported upload source
• Invalid Composio CLI release tag: ${releaseTag}

AI-assisted analysis of ComposioHQ/composio@64b1b85502 (2026-08-28). Data as JSON: /api/errors/7c83bb761ce676e3. Report an issue: GitHub.