transloadit/uppy · warning · Error

Missing S3 object key for aborting upload

Error message

Missing S3 object key for aborting upload

What it means

The OAuth callback route /:providerName/callback requires a providerName URL parameter. This 400 is returned when the parameter is absent, not a string, or an empty string, meaning Express matched the route but the path segment is empty/invalid.

Source

Thrown at packages/@uppy/aws-s3/src/S3Uploader.ts:223

  }

  #pause(): void {
    this.#abortController?.abort()
  }

  /**
   *
   * @param opts - `abortInS3`: Whether to also abort the multipart upload in S3. Default: true. Set to false to keep the multipart upload in S3 active, allowing for manual cleanup later and preventing accidental data loss if the user later tries to resume the upload.
   */
  abort(opts?: { abortInS3?: boolean }): void {
    this.#abortController?.abort()

    // Clean up event listeners
    this.#eventManager.remove()

    if (opts?.abortInS3 !== false && this.#uploadId) {
      if (!this.#key) {
        throw new Error('Missing S3 object key for aborting upload')
      }
      this.#options.s3Client
        .abortMultipartUpload({ key: this.#key, uploadId: this.#uploadId })
        .catch((abortErr) => {
          this.#options.log?.(abortErr, 'warning')
        })
    }

    this.#key = undefined
    this.#uploadId = undefined
    this.#uploadHasStarted = false
  }

  async #resumeMultipartUpload(
    uploadId: string,
    signal: AbortSignal,
  ): Promise<void> {
    if (!this.#key) {

View on GitHub (pinned to 5d4dedd02a)

Solutions

1. Ensure the callback URL includes the provider name, e.g. /connect/drive/callback
2. Check the redirect URI registered with the OAuth provider matches `${companionUrl}/connect/:providerName/callback`
3. Verify server.path prefix and proxy rewriting are not stripping the provider segment
4. Confirm the route is mounted via the connect router and not hit directly at root

Example fix

// before
GET /connect/callback
// after
GET /connect/drive/callback

const providerName = 'drive'
if (!providerName || typeof providerName !== 'string') throw new Error('provider name required')
await fetch(`${companionUrl}/connect/${encodeURIComponent(providerName)}/callback`)

const isValidProviderName = (p: unknown): p is string =>
  typeof p === 'string' && p.length > 0

When it happens

Trigger: Calling /connect/callback, /connect//callback, or manually constructing a callback URL without the provider segment; also a misconfigured grant callback URL or a provider OAuth app whose redirect URI points at the wrong path.

Common situations: Wrong redirect URI configured in the provider's OAuth app; a reverse proxy or load balancer rewriting the path; typo'd companionUrl/server.path options so the callback path is truncated.

Related errors

• Missing S3 object key for resuming upload
• Missing S3 object key for uploading part
• companionEndpoint must be a string
• s3Endpoint must be a string
• No key returned

AI-assisted analysis of transloadit/uppy@5d4dedd02a (2026-08-28). Data as JSON: /api/errors/15ba26b19fca9921. Report an issue: GitHub.