paperclipai/paperclip · error · GitHubAttachmentUnavailableError

github_attachment_source_mismatch

github_attachment_source_mismatch

Error message

github_attachment_source_mismatch

What it means

After checking App authority, resolveGitHubAttachmentComment validates the request shape with isGitHubAttachmentCommentRequest. A request that is not a recognized GitHub attachment comment request (wrong origin, malformed fields, or a URL/attachment from another provider) causes GitHubAttachmentUnavailableError('github_attachment_source_mismatch'), signaling the request does not correspond to a canonical GitHub source this runtime can resolve.

Source

Thrown at server/src/services/chat-sdk-runtime.ts:2839

    signal: AbortSignal,
  ): Promise<Buffer> {
    const fetcher = this.teamsInlineImageFetchers.get(attachment);
    if (!fetcher || signal.aborted)
      throw new Error("Teams inline image download unavailable");
    return await fetcher(signal);
  }

  /** Called only after current inbound admission; installation App authority only. */
  async resolveGitHubAttachmentComment(
    request: GitHubAttachmentCommentRequest,
    signal: AbortSignal,
  ): Promise<unknown> {
    if (!this.githubAttachmentAppAuthority)
      throw new GitHubAttachmentUnavailableError(
        "github_attachment_canonical_authority_unavailable",
      );
    if (!isGitHubAttachmentCommentRequest(request))
      throw new GitHubAttachmentUnavailableError(
        "github_attachment_source_mismatch",
      );
    try {
      signal.throwIfAborted();
      const result = await (this.adapter as GitHubAdapter).octokit.request(
        `GET ${request.url}`,
        {
          headers: {
            accept: request.accept,
            "x-github-api-version": "2022-11-28",
          },
          request: {
            signal,
            redirect: "manual",
            fetch: githubAttachmentCommentFetch(request, signal),
          },
        },
      );

View on GitHub (pinned to 01ad858492)

Solutions

1. Build the GitHubAttachmentCommentRequest from the admitted inbound attachment data, not manually
2. Verify the attachment origin is GitHub and the URL matches the expected GitHub API shape
3. Regenerate/re-admit the request if persisted data predates a validator/schema change
4. Confirm you are calling the GitHub resolver with GitHub-sourced attachments only

Example fix

// before
await runtime.resolveGitHubAttachmentComment({ url: someUrl } as any, signal);
// after
if (isGitHubAttachmentCommentRequest(req)) {
  await runtime.resolveGitHubAttachmentComment(req, signal);
}

if (!isGitHubAttachmentCommentRequest(request)) throw new Error('not a GitHub attachment comment request');

const isGitHubAttachmentCommentRequest = (r: unknown): r is GitHubAttachmentCommentRequest => typeof r === 'object' && r !== null && typeof (r as any).url === 'string' && (r as any).url.startsWith('https://api.github.com/');

try { return await runtime.resolveGitHubAttachmentComment(request, signal); } catch (e) { if ((e as Error).message === 'github_attachment_source_mismatch') { /* rebuild request from admitted inbound data */ } else throw e; }

When it happens

Trigger: Passing a GitHubAttachmentCommentRequest whose payload fails isGitHubAttachmentCommentRequest validation — e.g. an attachment captured from Slack/Teams reused here, a hand-built request missing required GitHub fields, or a URL outside the expected GitHub domain/repo.

Common situations: Cross-provider attachment handling bugs; schema drift after shared-type updates so older persisted requests no longer validate; constructing the request manually instead of from admitted inbound data.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• github_attachment_canonical_response_unavailable
• github_attachment_canonical_html_unavailable
• github_attachment_canonical_file_unsupported
• github_attachment_canonical_image_count_invalid
• github_attachment_canonical_target_denied

AI-assisted analysis of paperclipai/paperclip@01ad858492 (2026-09-10). Data as JSON: /api/errors/da5640f0bc6dc5bb. Report an issue: GitHub.