PR 29388 runtime verification, 2026-11-02 UTC
main and PR used isolated development state; project and threads created through the web app.
real Chrome driven with repository Playwright; real fx 0.0.16; two configured Chat Completions backends point to the live local proxy, both run gpt-6.1-sol. No simulated provider.

$ git rev-parse HEAD
31616ad4bdb1f6459c4eaf386534648689449dc1

$ git rev-parse github/main
9bcf75335f9b2a8af877e1317c809b72a070b280

$ /home/user/.local/bin/fx --version
0.0.16

$ /home/user/.local/bin/fx status --json | jq '{model,model_source,auth,workspace}'
{
  "model": "gpt-6.1-sol",
  "model_source": "alternate",
  "auth": "configured provider",
  "workspace": "/home/user/t3code"
}

$ /home/user/.local/bin/fx status --json | jq '{model,model_source,auth,workspace}'
{
  "model": "gpt-6.1-sol",
  "model_source": "proxy",
  "auth": "configured provider",
  "workspace": "/home/user"
}

fx saved session backend/model transitions (credential bindings omitted):
session 5313qnz9MmC5
{"seq":2,"backend":"proxy","model":"gpt-6.1-sol"}
{"seq":5,"kind":"turn_started","turn":1}
{"seq":15,"backend":"alternate","model":"gpt-6.1-sol"}
{"seq":16,"kind":"turn_started","turn":2}
{"seq":23,"backend":"proxy","model":"gpt-6.1-sol"}
{"seq":24,"kind":"turn_started","turn":3}
{"seq":30,"backend":"alternate","model":"gpt-6.1-sol"}
{"seq":31,"kind":"turn_started","turn":4}
{"seq":37,"backend":"proxy","model":"gpt-6.1-sol"}
{"seq":38,"kind":"turn_started","turn":5}
{"seq":44,"kind":"turn_started","turn":6}
session ehLYpQXEjtpB
{"seq":2,"backend":"alternate","model":"gpt-6.1-sol"}
{"seq":5,"backend":"proxy","model":"gpt-6.1-sol"}
{"seq":6,"kind":"turn_started","turn":1}
{"seq":15,"backend":"alternate","model":"gpt-6.1-sol"}
{"seq":16,"kind":"turn_started","turn":2}

Observed in web client:
main: CODEX_MAIN_OK via Codex gpt-6.1-sol; FX_MAIN_OK via fx proxy.
PR: CODEX_PR_OK via Codex gpt-6.1-sol.
PR same fx session: FX_ALTERNATE_OK -> FX_PROXY_OK -> FX_ALTERNATE_AGAIN_OK -> FX_DEFAULT_OK.
PR second fx thread: BACKEND_PROXY_OK -> FOLDER_DEFAULT_ALTERNATE_OK.
search returned both proxy and alternate model choices; signed-out built-in headings disabled with login hints.

Focused existing tests through blacksmith-check: 46 passed in 4 files.
check:changed through blacksmith-check, against ac8dce0cc3ab: passed.
Formatting, lint, both Knip passes, GraphQL, unused patches, 39 affected-package typechecks, 56 adjacent tests in 7 files, 9 selected React Compiler checks.
The initial remote attempts lacked a merge base. Fetching the PR head history from its contributor branch restored the graph; the final run passed.