fix(web): pin Next.js back to 16.3.5 to restore /flows and /docs (prod 500s)

Closed
KH
4d ago
+43-43

Production incident

https://agentrelay.com/flows and every https://agentrelay.com/docs/<slug> page (e.g. /docs/introduction) have returned 500 Internal Server Error since #126 (Next.js 16.3.5 ā†’ 16.3.8) deployed at 2026-10-02 04:40 UTC.

This PR reverts 646f9cc. Only web/package.json and package-lock.json change, back to exactly what was deployed and healthy on 2026-10-01.

Evidence

  • The preview build of #126, which contains only the version bump, returns 500 on /flows and /docs/introduction (https://8b743c8b-agentrelay-web.agent-workforce.workers.dev). So do the previews of #127 and #128, which were built on top of it.
  • Under 16.3.8 every prerendered page answers with x-nextjs-cache: MISS, including pages that return 200 (/, /blog, /about). The static-assets incremental cache is no longer hit, so the Worker renders at request time. web/open-next.config.ts and the Populate static-assets cache step in deploy.yml both document that a runtime render of docs pages fails in the Workers runtime.
  • The same 500 is returned by origin-web.agentrelay.com directly, so the router Worker is not involved.
  • Upstream report of the same mechanism: opennextjs/opennextjs-aws#1269 ("Next 16.3.8: build-time prerendered entries are never read").

Not yet captured: the runtime exception from the Worker logs. The cache-miss mechanism is inferred from response headers and the upstream report.

How to verify before merging

On this PR's preview URL, both of these should return 200:

  • /flows
  • /docs/introduction

Follow-ups (not in this PR)

  • Do not re-attempt the 16.3.8 upgrade until the OpenNext adapter reads the new prerender cache keys.
  • CI and the preview workflow passed on #126 while two top-level pages were 500ing. A post-build smoke check of a few prerendered routes on the preview would have caught it.

@khaliqgant ā€” needs the two reviews plus a human merge to deploy.

šŸ¤– Generated with Claude Code

[!NOTE]
Cursor Bugbot is generating a summary for commit 186d503abdc02fcbbb94a65b342bb5d583be8ed1. Configure here.

Summary by cubic

Pins Next.js back to 16.3.5 to restore /flows and /docs pages, which have returned 500 in production since the 16.3.8 upgrade.

With 16.3.8 the OpenNext adapter stops hitting the static-assets cache (every prerendered page answers x-nextjs-cache: MISS), so pages that can't render in the Workers runtime fail at request time. The diff is only the version pin in web/package.json and package-lock.json, reverting to the exact healthy build from 2026-10-01.

  • Do not retry the 16.3.8 upgrade until @opennextjs/cloudflare reads the new prerender cache keys.

Agent Relay sessions

  • claude session fe983435 Ā· opened via gh pr create Ā· last active 2026-10-02