session: automatic titles fail with 403 FreeTierError when using free models #58521

Summary

Session titles never generate on OpenCode 2.1.4 when the only available models are the free opencode models: the internal title request is rejected with 403 FreeTierError, so sessions stay unnamed.

Environment

• opencode version: 2.1.4 (npm @opencode/cli, channel latest)
• OS: Windows Server 2022, Windows_NT 10.0.20348 (win32 x64)
• Terminal: VS Code integrated terminal (TERM_PROGRAM=vscode, COLORTERM=truecolor)
• Shell: cmd.exe (C:\Windows\system32\cmd.exe)
• Install/channel: npm/nvm global install, release build
• Active plugins: local global plugin ~/.config/opencode/plugins/session-title.js (workaround described below); ~/.opencode/plugins/graphify.js

Reproduction

1. Use a fresh OpenCode 2.1.4 install with no authenticated providers, so only the free opencode models are available (opencode auth list reports "No authenticated integrations").
2. Create a session and send one message, for example opencode run "hola".
3. Inspect the session: opencode api get "/api/session?limit=5" shows an empty title.
4. Force regeneration: opencode api patch /api/session/<id> --data '{"title":""}'. The title stays empty.
5. Reproduce the failing request directly: opencode run --standalone --agent title "hola" fails with the FreeTierError below, while the same model with the build agent succeeds.

Expected Behavior

The session receives a generated title (for example "Saludo inicial"), the same way it does with paid or authenticated providers.

Actual Behavior

The title request fails with HTTP 403:

{"type":"error","error":{"type":"FreeTierError","message":"OpenCode's free tier can only be used from within OpenCode. Download it at https://opencode.ai and keep building."}}

No title is stored, and the session UI shows no error, so the only symptom is unnamed sessions.

Additional Context

• Captured through a local reverse proxy in front of https://opencode.ai/inference/openai/v1: the primary build request carries 12 tools and returns 200; the title request carries no tools at all and returns 403 with the body above.
• Sessions created on 2026-10-21/22 with big-pickle and mimo-v2.6-flash-free did get titles, so this looks like a change in the free-tier gate rather than in the title code.
• Config-level attempts that do not help:
  • agents.title.permissions = [{ "action": "*", "resource": "*", "effect": "allow" }] fixes opencode run --agent title ... (that request then includes tools) but not the internal session title path.
  • Injecting a dummy tool through a model body.tools override: the tool reaches the wire (toolsCount: 1) but the request is still rejected with 403, so tool presence alone is not what the gate checks.
• What does work: POST /api/session/{id}/generate with {"prompt": "..."} returns generated text with the same free model, and ctx.session.generate from a plugin behaves the same. I used that in a ctx.session.hook("title", ...) plugin that sets event.result, which restores titles without issuing the failing request.
• Frequency: 100% reproducible with free models on Windows; there is no authenticated provider on this machine to compare against.