githubsim

Answers the GitHub calls the github module makes, serves the App install page, and sends HMAC-signed webhooks to the stack. Code: services/sims/githubsim, spec specs/setup/github-simulator.feature. It checks no JWT signature (the App id in the claims and expiry only). Console: https://github.<slug>.langwatch.localhost (a plain page: installations, pull requests, fault count).

Run it

• Opt-in: haven up +github (sticky; restarts the stack). Runs in the go lane by default (see sims).
• The overlay sets GITHUB_LANGY_APP_ID, _APP_SLUG, _PRIVATE_KEY (a throwaway RSA key), _WEBHOOK_SECRET, and the two origin leaves GITHUB_LANGY_API_BASE and GITHUB_LANGY_WEB_BASE (both the sim). With +github the whole set beats a real GITHUB_LANGY_* App in .env (unlike Stripe, where .env wins); drop +github to use your own.
• The sim is told the stack's /api/github/webhook and /api/github/setup and the same secret.
• Seeded: installation 1001 on langwatch-demo with repos langwatch-demo/app, langwatch-demo/docs, and PR #1 on feat/demo. User octocat.
• Social sign-in with GitHub is the IdP overlay's job, not the GitHub App's: with idpsim on, the stack gets GITHUB_SIGN_IN_BASE pointing at idpsim (tools/thuishaven/domain/overlay_idp_social.go; see idpsim). This sim's OAuth routes below serve the GitHub App flow.

What it fakes

GET  /app/installations/{id}                       App JWT
POST /app/installations/{id}/access_tokens         App JWT; 422 for a permission not granted
GET  /installation/repositories                    token; paged
GET|POST /repos/{o}/{r}/pulls   GET .../pulls/{n}   head=owner:branch, state=
POST|GET /repos/{o}/{r}/check-runs | commits/{sha}/check-runs
GET  /apps/{slug}/installations/new?account=<login>&state=…   redirects to the setup URL
GET  /login/oauth/authorize | POST /login/oauth/access_token | GET /user, /user/emails

/github-apps/{slug}/installations/new is the same page. Without account it lists accounts.

For gh and git (what Langy's worker runs): every REST route above also answers under /api/v3; POST /api/graphql answers gh's RepositoryInfo, PullRequestForBranch and PullRequestCreate (a repo outside the token's installation is GitHub's NOT_FOUND); GET /{o}/{r}.git/info/refs, git-upload-pack and git-receive-pack serve clone and push over a bare repo per repository (README on main; token as the Basic password; GITHUBSIM_GIT_ROOT, default a temp dir).

Drive it

haven sim github status | list | pulls | calls | deliveries --json
haven sim github install --account acme --deliver        # new installation + signed webhook
haven sim github pr open --repo langwatch-demo/app --head feat/x --deliver
haven sim github pr merge --repo langwatch-demo/app --number 1 --deliver
haven sim github app suspend|unsuspend|delete|add-repo|remove-repo --installation 1001 --deliver
haven sim github deliver --event pull_request --action closed --repo langwatch-demo/app --number 1 [--bad-signature|--omit-signature]
haven sim github fault add --status 429 --retry-after 30 --match /pulls --times 1
haven sim github fault list | clear      haven sim github clear | reset

--match is a substring of METHOD /path. Faults answer GitHub's JSON error body; 429 and 403-with-Retry-After set X-RateLimit-Remaining: 0. POST /_sim/api/tokens/expire makes every minted token answer 401. Without haven: make service svc=githubsim (:5596; GITHUBSIM_WEBHOOK_URL, _WEBHOOK_SECRET, _SETUP_URL, _APP_ID, _SEED=1).

Row recipes

• GH-01/GH-02/GH-F1: Settings > Integrations > Connect; the popup lands on the sim's install page; click an account; the setup redirect returns and the connected state shows.
• GH-11: an installation made with haven sim github install before the connect flow is refused (not-from-flow). Connect through /api/github/install?organizationId=<org> first, then haven sim github app add-repo --installation <id> --repo big/rN for 150 repos (one repo per call, so loop).
• GH-13/GH-31: app delete --installation <id> --deliver, then reconnect; PR history stays.
• GH-15: do not select +github and leave GITHUB_LANGY_APP_ID unset.
• CA-15/CA-41: pr open|merge --deliver then the Pull Requests page; fault add --status 429 --retry-after 30 --match /pulls for the snapshot-on-rate-limit state.
• CA-21/CA-37/CA-38/CA-40/CA-42: a PR whose --head equals the coding session's branch, opened with --deliver, binds usage to the project. Pass host=github.com to the PR usage APIs when PRs were stored before +github: the default host is now the githubsim host.
• LANGY-09/LANGY-45: with +github +langy haven sets LANGY_GITHUB_HOST to the sim, so the worker's gh and git reach it (GH_HOST, GH_ENTERPRISE_TOKEN, a git rewrite of github.com). Script the turn with llmsim /tool bash lines (gpt-5-mini in the composer). gh drops the port from a git remote, so in a clone run gh pr create -R "$GH_HOST/<owner>/<repo>" --head <branch>. The worker's $HOME/work goes when the worker idles out (2 min on the host tier): one turn per flow.