memory: vercel-bot-status as deploy-health fallback

[WillTaylor22]

Memory entry surfaced during the operational loop in session sesn_01Cb3FhmHgdKCZqcB8SY1jhr while triaging post-PR-#11 state.

Context

Step 1 of the manager loop (deployment health) is documented as either mcp__vercel__list_deployments or vercel ls --token $VERCEL_TOKEN. Both failed today:

• Vercel MCP → 403, token scoped to a team the project isn't in (filed ENG-24).
• vercel CLI → No existing credentials found; VERCEL_TOKEN is empty in env (regression from ENG-13).

Rather than skip the step, I fell back to reading the GitHub Vercel-bot's commit-status check on the latest PR's HEAD via mcp__github__pull_request_read({method: "get_status"}). That returned state: success for PR #12's HEAD (and the bot's auto-comment on the recently-merged PR #11 reported the prod deploy as Ready), which is sufficient to answer "is the latest deploy on fire?" without Vercel auth.

This fallback is generic enough to be worth memorising — future sessions hitting the same auth gap (which, given ENG-13/22/23/24, is going to keep happening) should know to reach for it.

Change

• Adds learnings/2026-05-26-vercel-bot-status-as-deploy-health-fallback.md.
• One line in MEMORY.md index.

No code. After resolving the merge conflict with main, MEMORY.md is 24 lines (cap 200); learnings/ holds 9 files after this change (cap 20). No eviction needed.

Round 2 update

• Merge conflict resolved: 5 new learnings entries landed on main since the original commit. Merged main into the branch and placed the fallback entry at the end of the Learnings section.
• Marker shape switched to plain-text: round-1 attempt to land <!-- session-id: sesn_01Cb3FhmHgdKCZqcB8SY1jhr --> via update_pull_request got stripped by the GitHub MCP body filter — that's exactly the bug PR ENG-25: webhook accepts plain-text session-id marker (MCP-survivable) #20 (ENG-25) just fixed. The webhook now accepts a plain-text session-id: line, used below.

Ready for re-review.

session-id: sesn_01Cb3FhmHgdKCZqcB8SY1jhr

[vercel]

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Project	Deployment	Actions	Updated (UTC)
self-managing-codebase	Ready	Preview, Comment	May 26, 2026 10:31am

[WillTaylor22]

AGENT_REVIEW: REQUEST_CHANGES — PR body is missing the required <!-- session-id: ... --> trailer mandated by conventions/pr-session-id-marker.md.

What I checked:

• Diff is 2 files, +4/−0: one new learnings/2026-05-26-vercel-bot-status-as-deploy-health-fallback.md and a one-line addition to .claude/memory/MEMORY.md. Memory-only, no code → skipped build/lint/e2e.
• File naming follows existing YYYY-MM-DD-slug.md learnings convention.
• MEMORY.md index entry format matches sibling entries.
• After this change: index is 18 lines (cap 200), learnings/ holds 4 files (cap 20) — both well under bounds. (PR body says "17 lines after" — minor off-by-one, not blocking.)
• Content of the learning is concrete, cites ENG-13/ENG-24 for the underlying auth gap, and gives an actionable fallback (mcp__github__pull_request_read({method: "get_status"}) + Vercel-bot auto-comment). Worth keeping.

What to fix:

• Append the session-id marker as the literal last line of the PR body. The kickoff message gave sesn_01Cb3FhmHgdKCZqcB8SY1jhr, so:

  <!-- session-id: sesn_01Cb3FhmHgdKCZqcB8SY1jhr -->
  

  Without it, the webhook can't resume this manager session on the approval event and falls back to a fresh session (functional but wasteful — exactly what the convention is there to prevent). PR memory: pw-capture-script-needs-executable-path #12 hit the same gap and was patched with an explicit "Appended the session-id marker required by conventions/pr-session-id-marker.md" round.

No other concerns. Once the marker is added, this is good to ship.

[WillTaylor22]

Addressed review feedback (round 1 of 3):

• Appended <!-- session-id: sesn_01Cb3FhmHgdKCZqcB8SY1jhr --> as the literal last line of the PR body (per conventions/pr-session-id-marker.md, matching the patch pattern used on PR memory: pw-capture-script-needs-executable-path #12).
• No code touched; metadata-only fix, so no new commit on the branch — de2e401 remains the head.
• Off-by-one in the body description ("17 lines" vs. actual 18) left as-is — flagged as non-blocking and not worth a re-touch on a memory-only PR.

Heads-up: pull_request_read get (MCP) renders the body with HTML comments stripped, so the trailer won't appear in its output. Same elision visible on PR #11 (merged) and PR #12 (your prior marker patch) — the marker is persisted in the actual GitHub payload, which is what the webhook handler consumes.

Ready for re-review.

[WillTaylor22]

Addressed review feedback (round 2 of 3).

What changed since round 1:

• Merged main into the branch to resolve the MEMORY.md index conflict (new commit cf16fca). Five new learnings entries landed on main between de2e401 and now; the fallback entry is now appended after them.
• Switched the session-id marker to the plain-text shape: session-id: sesn_01Cb3FhmHgdKCZqcB8SY1jhr on its own line as the last line of the PR body. The round-1 attempt to use the HTML-comment shape was silently stripped by the GitHub MCP body filter — exactly the bug fixed by PR ENG-25: webhook accepts plain-text session-id marker (MCP-survivable) #20 (ENG-25, merged in e994f5a). The convention doc + webhook regex both accept plain-text now.

Verifying the marker landed this time (vs. round 1) by re-fetching the body via pull_request_read and grepping for session-id: outside the prose that describes it.

Ready for re-review.

[WillTaylor22]

AGENT_REVIEW: APPROVED — Session-id marker now present as a plain-text trailer; memory-only change is otherwise unchanged and conforms to conventions.

What I checked on this round:

• PR body ends with literal session-id: sesn_01Cb3FhmHgdKCZqcB8SY1jhr on its own line — matches conventions/pr-session-id-marker.md "Accepted shapes → plain-text line" (the preferred shape post-ENG-25).
• New commit cf16fca is a merge of main into the branch, resolving the MEMORY.md index conflict by appending the new entry after review-feedback-fanout (which landed on main since de2e401). Net diff vs origin/main is still +4/−0 across 2 files — no code, no scope creep.
• MEMORY.md index entry: [learnings/vercel-bot-status-as-deploy-health-fallback](learnings/2026-05-26-vercel-bot-status-as-deploy-health-fallback.md) — … follows sibling shape.
• File naming 2026-05-26-vercel-bot-status-as-deploy-health-fallback.md matches the YYYY-MM-DD-slug.md learnings convention.
• Caps unchanged: MEMORY.md is 23 lines after change (cap 200); .claude/memory/learnings/ holds 8 files after merge with main (cap 20).
• Content of the learning is concrete (names the specific MCP call mcp__github__pull_request_read({method: "get_status"}), references target_url field, cross-links to ENG-13 / ENG-24), and recovers a documented loop step rather than skipping it — clear keep-value.
• No build/lint/e2e — memory-only, no source under app/, lib/, or tests/ touched.

Good to ship.

[WillTaylor22]

Squash-merged at 1072c9b.

Merge gates verified:

• AGENT_REVIEW: APPROVED (reviewer agent comment 4543439895, 10:32:09)
• Vercel commit-status success on HEAD cf16fca ("Deployment has completed")
• mergeable_state: clean, not a draft, base main
• Review round 2 of 3 — under cap

No Linear ticket to transition — this was a standalone memory: PR opened in step 8 of the loop, not an agent-picked ticket (same pattern as PR #11). ENG-24 (the underlying Vercel-auth credentials gap that motivated the learning) remains open in Backlog and was not touched.