[BUG] Claude Code desktop, GitHub MCP integration. Private repo (details available privately on request).

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?

After calling mcp__github__subscribe_pr_activity on a PR (the tool returns "Subscribed to activity on …"), no <github-webhook-activity> events are delivered into the conversation for any subsequent activity on that PR. This affects all event types I tested: PR issue comments, inline review comments (from both me and a third-party bot), and CI check_run status changes.

The events do exist on GitHub's side — they are retrievable via mcp__github__pull_request_read polling — so the GitHub-side webhook is firing. The harness bridge that's supposed to forward them into the conversation as <github-webhook-activity> messages appears to be silently dropping them.

Idempotent re-subscription (calling mcp__github__subscribe_pr_activity again) does not fix it; the tool returns success but no events are delivered.

What Should Happen?

After successfully subscribing to PR activity, each subsequent PR event (issue comment, pull_request_review_comment, pull_request_review, check_run status change) should arrive in the conversation as a <github-webhook-activity> message so I can react to it without manual polling.

In particular: an inline review comment posted on a file in the PR diff should fire a webhook event delivered to the subscribed session within a few seconds.

Error Messages/Logs

mcp__github__subscribe_pr_activity returned:
  "Subscribed to activity on atk0309/project_zeroday#42. Comments, CI status changes, reviews, and other PR events will now be delivered into this conversation as <github-webhook-activity> messages."

(Called twice during the session — both returned the same success string. No <github-webhook-activity> events arrived afterwards.)

Events that DID exist on GitHub but were NOT delivered (all retrievable via mcp__github__pull_request_read polling):

  2026-04-29T10:51:37Z  issue_comment            id=4343017547
  2026-04-29T10:54:46Z  issue_comment            id=4343037017
  2026-04-29T10:55:04Z  pull_request_review_comment  id=3160406826  (third-party bot, chatgpt-codex-connector)
  2026-04-29T11:03:01Z  pull_request_review_comment  id=3160451919
  ~2026-04-29T10:29:42Z check_run                "test" → success

Steps to Reproduce

1. In a Claude Code session on the web, open a private repository and create a feature branch with at least one commit.
2. Open a pull request via mcp__github__create_pull_request (or the GitHub UI).
3. Call mcp__github__subscribe_pr_activity for that PR. Observe the success response: Subscribed to activity on <owner>/<repo>#<n>. …
4. From the GitHub web UI (logged in as a different user / different tab from the agent), post a top-level PR comment.

• Expected: <github-webhook-activity> message in the conversation.
• Actual: nothing arrives.

1. Open the PR's Files changed tab and post an inline review comment on a specific line of the diff (the blue + icon → Add single comment).

• Expected: <github-webhook-activity> message in the conversation.
• Actual: nothing arrives.

1. Wait for CI to transition status (or trigger a re-run).

• Expected: <github-webhook-activity> message on completion / failure.
• Actual: nothing arrives.

1. Call mcp__github__pull_request_read with method get_comments and get_review_comments — all the events from steps 4–6 are present, confirming GitHub sent them; the harness webhook bridge dropped them.

Notes:

• Repo is private. Happy to share session ID, PR diff, or grant a maintainer temporary read access via a separate channel if it helps debugging.
• Re-subscribing (calling mcp__github__subscribe_pr_activity a second time) returns success but does not restore delivery.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

It worked on previous version last night 28 April. I updated to latest version today 29-th April and it broke.

Claude Code Version

2.1.123 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

I am using Claude Code desktop