[BUG] Claude GitHub App cannot be installed / no write access granted

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The Claude GitHub App required for Claude Code (web) to push commits and open pull requests does not appear to be installed on my GitHub account, so all push operations fail with 403 "Resource not accessible by integration." I have OAuth-level authorization for Claude but the App itself is not listed under GitHub's "Installed GitHub Apps."

What Should Happen?

After connecting GitHub in Claude Settings > Connectors, the Claude GitHub App should be installed on the target repository with Read & Write permissions, allowing the session to push commits directly and let me create a pull request from GitHub's UI.

Error Messages/Logs

- `git push`: `fatal: unable to access '...': The requested URL returned error: 403`
- GitHub API (via MCP `create_branch` / `push_files`): `403 Resource not accessible by integration` when calling `POST https://api.github.com/repos/trangle-94/vn-stock-data/git/refs`

Steps to Reproduce

1. Start a Claude Code (web) session on repo trangle-94/vn-stock-data
2. Make commits on a feature branch (e.g. claude/dreamy-darwin-t8jj7o)
3. Attempt to push via git push -u origin <branch> or via the GitHub MCP tool
4. Push fails with 403
5. Check GitHub Settings > Applications:

• "Authorized GitHub Apps" → Claude is listed
• "Installed GitHub Apps" → Claude is NOT listed

1. Disconnect/reconnect the GitHub connector in Claude Settings > Connectors → no GitHub App installation prompt appears
2. Repo Settings > Integrations/installations → no Claude App present
3. Searched GitHub Marketplace for "Claude" → no matching official app found

Claude Model

_No response_

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.218

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Non-interactive/CI environment

Additional Information

_No response_