Failed to copy attachment "${metadata.filename}" into this w

Error message

Failed to copy attachment "${metadata.filename}" into this worker workspace: upload did not return a path

What it means

If uploadInbox reports success (result.ok !== false) but returns an empty/whitespace result.path, the client cannot reference the uploaded file, so it throws this error. This guards against a malformed success response where the stored file path is missing.

Source

Thrown at apps/app/src/react-app/domains/session/sync/attachment-file-part.ts:384

    const id = input.createId ? input.createId() : randomAttachmentId();
    const inboxPath = buildChatAttachmentInboxPath({
      sessionId: input.sessionId,
      filename: metadata.filename,
      id,
    });

    let result: InboxUploadResult;
    try {
      result = await input.endpoint.client.uploadInbox(workspaceId, file, { path: inboxPath });
    } catch (error) {
      throw new Error(uploadErrorMessage(metadata.filename, error));
    }

    if (result.ok === false) {
      throw new Error(`Failed to copy attachment "${metadata.filename}" into this worker workspace: upload was rejected`);
    }
    if (!result.path.trim()) {
      throw new Error(`Failed to copy attachment "${metadata.filename}" into this worker workspace: upload did not return a path`);
    }
    if (result.bytes !== file.size) {
      throw new Error(`Failed to copy attachment "${metadata.filename}" into this worker workspace: expected ${file.size} bytes, wrote ${result.bytes}`);
    }

    const workspacePath = workspaceInboxPath(result.path);
    const absolutePath = joinWorkspaceRelativePath(workspaceRoot, workspacePath);
    uploaded.push({
      filename: metadata.filename,
      mime: metadata.mime,
      bytes: result.bytes,
      workspacePath,
      url: toFileUrl(absolutePath),
      file,
    });
  }

  return [

View on GitHub (pinned to 2b7df46e8a)

Solutions

Fix or upgrade the server so uploadInbox always returns the stored inbox path on success.
Verify no proxy/middleware is dropping the path field from the response.
Retry the upload; if reproducible, log the raw response for a bug report.

Example fix

// after uploadInbox resolves: if (!result.path?.trim()) { console.error('uploadInbox response missing path', result); } // report server bug

Defensive patterns

Strategy: type-guard

Type guard

function hasUploadPath(result: { ok?: boolean; path?: string }): result is { ok?: boolean; path: string } { return typeof result.path === 'string' && result.path.trim().length > 0; }

Try / catch

try { await composerAttachmentsToWorkspaceFileParts({ attachments, endpoint, sessionId, workspaceRoot }); } catch (e) { if (String(e.message).includes('upload did not return a path')) { reportServerBug(e); } else { throw e; } }

Prevention

Pin compatible client/server versions of the uploadInbox contract.
Ensure proxies/middleware do not strip response fields.
Add a server-side test asserting uploadInbox returns a non-empty path on success.

When it happens

Trigger: Server returns a success envelope without a path — e.g. a server bug, a proxy stripping the response body field, or a protocol version mismatch where the path is under a different key.

Common situations: Running a newer client against an older server (or vice versa) that omits 'path'; custom server implementations of uploadInbox that forget to return the path.

Related errors

AI-assisted analysis of different-ai/openwork@2b7df46e8a (2026-09-01). Data as JSON: /api/errors/ffd1df521dada12a. Report an issue: GitHub.