copilot-model: add claude-opus-5.5 to SUPPORTED_COPILOT_MODELS (GA in Copilot 2026-09-22; AWF rejects it pre-request)

[matiloti]

Summary

claude-opus-5.5 became generally available in GitHub Copilot on 2026-09-22 (changelog), but it is not in SUPPORTED_COPILOT_MODELS in src/copilot-model.ts — not in the latest release (v0.28.23, 2026-09-22) and not on main. Because validateCopilotModel() runs host-side before any container starts, every gh-aw workflow that sets engine.model: claude-opus-5.5 fails in the Execute GitHub Copilot CLI step with zero requests made:

[ERROR] Error: model 'claude-opus-5.5' is unsupported or unrecognized by this AWF version. Did you mean 'claude-opus-5'?

This is the same lag pattern as #6682 (claude-opus-5 missing from the allowlist while Copilot already served it).

Environment

• gh-aw compiler v0.88.2, engine.id: copilot, Copilot CLI pinned 1.0.70
• AWF v0.27.31 (sandbox.agent.version); verified the allowlist gap also in v0.28.23 and main
• GHES tenant with a data-residency Copilot API (engine.api-target), ubuntu-latest runners

Evidence

src/copilot-model.ts on main (Claude section of SUPPORTED_COPILOT_MODELS):

  'claude-fable-5',
  'claude-haiku-4.5',
  'claude-mythos-5',
  'claude-opus-4.8',
  'claude-opus-5',
  'claude-sonnet-5',
  'claude-sonnet-4.5',
  'claude-sonnet-4.6',

Observed instance of the gate on the same tenant with claude-opus-5 against AWF v0.27.31 (which predates that entry), failing weekly since 2026-09-06:

  COPILOT_MODEL: claude-opus-5
[ERROR] Error: model 'claude-opus-5' is unsupported or unrecognized by this AWF version. Did you mean 'claude-opus-4.8'?
##[error]Agent execution exited with code 1

docs/model-api-mapping.json already routes the new model via the claude-opus-5* pattern under family claude-opus-5, so only the allowlist and the pricing table are missing.

Root cause

SUPPORTED_COPILOT_MODELS is a hard-coded set with no override, and the automated Model API Mapping Updater only refreshes docs/model-api-mapping.json; it does not add new Copilot models to the allowlist or to containers/api-proxy/ai-credits-pricing.js. New Copilot models are therefore rejected until someone edits the set by hand.

Suggested fix (plan)

1. src/copilot-model.ts: add 'claude-opus-5.5' to SUPPORTED_COPILOT_MODELS (next to 'claude-opus-5').
2. containers/api-proxy/ai-credits-pricing.js: add 'claude-opus-5-5' (dash-normalised key, matching the existing claude-opus-5 row). Anthropic list price for Opus 5.5 is $4.00 input / $0.20 cached input / $20.00 output per MTok; cache write follows the existing 1.25x convention ($5.00). Please confirm against the Copilot billing catalog before merging.
3. src/copilot-model-catalog-sync.test.ts: no exclusion needed — the model is exposed in the Copilot CLI, so the parity guard should pass once both tables carry it.
4. docs/model-api-mapping.json: no change (covered by claude-opus-5*); optionally extend the family notes to mention claude-opus-5-5.
5. Longer term (from claude-opus-5 and gpt-5.6-sol missing from allowlist and pricing while model-api-mapping already carries them — third recurrence, needs a cross-catalogue consistency check #6682): have the mapping-updater workflow diff the Copilot models catalog against SUPPORTED_COPILOT_MODELS and open an issue when a GA Copilot model is missing, so this stops recurring on every model launch.

Related

• claude-opus-5 and gpt-5.6-sol missing from allowlist and pricing while model-api-mapping already carries them — third recurrence, needs a cross-catalogue consistency check #6682 — same gap for claude-opus-5 / gpt-5.6-sol ("third recurrence")
• chore: update model-to-API mapping (2026-09-02) #8001 — 2026-09-02 mapping refresh (mapping only, no allowlist change)

[matiloti]

Related on the compiler side: github/gh-aw#62777 (automated model-alias inventory, 2026-09-23) already picked up claude-opus-5.5 from the Copilot SDK/reflect catalog with pricing $4.00 input / $20.00 output / $0.20 cache read / $5.00 cache write per MTok — the same figures as step 2 above — and concludes the compiler's alias wildcards need no change. That inventory does not cover this repo's SUPPORTED_COPILOT_MODELS, which is why the gap here goes unnoticed.