fix(provider): skip reasoningEffort for azure gpt-5.5 - #1148

Summary

ProviderTransform.options adds reasoningEffort: "medium" to any model whose api id contains gpt-5 (excluding gpt-5-chat/gpt-5-pro). Azure's gpt-5.5 matches that block, but Azure's completions API rejects the reasoningEffort parameter, so the request fails and the provider is unusable.

This adds an early-return guard: for @ai-sdk/azure models whose id contains gpt-5.5, set only reasoningSummary: "auto" and return before the shared gpt-5 block runs.

No local issue — this is an upstream-port fix.

Why

Without the guard, Azure gpt-5.5 users get a hard provider error on every request. The fix is the smallest adaptation of the upstream change to current dev (line numbers drifted; logic re-proven against the current gpt-5 block).

Related Issue

None. Ports upstream anomalyco/opencode#26222 (thanks @frederiknsgo).

Human Review Status

Pending

Review Focus

Guard placement and predicate: it sits after the enable_thinking blocks and before the shared gpt-5 block, keyed on api.npm === "@ai-sdk/azure" && api.id.includes("gpt-5.5"). Confirm it does not shadow other Azure gpt-5.x models (only gpt-5.5 is matched) and that returning early is correct (no later block in options applies to this case).

Risk Notes

Behavior change is scoped to Azure gpt-5.5 only; all other providers/models keep their existing options.

Known pre-existing limitation (out of scope, not a regression from this change): ProviderTransform.variants() still returns reasoningEffort entries for Azure gpt-5.5 reasoning variants, and session/llm.ts merges the selected variant's options after ProviderTransform.options(...). So if a user explicitly selects a reasoning-effort variant for Azure gpt-5.5, reasoningEffort is reintroduced and Azure still rejects it. The upstream fix (anomalyco/opencode#26222) has the same scope and also leaves the variant path untouched. Closing the variant path requires a product decision about whether Azure gpt-5.5 should expose reasoning-effort controls at all, plus a change at the out-of-scope merge site — tracked separately rather than expanded into this minimal port.

Skipped conditional checklist items:

• UI/copy item — no visible UI or copy changed (server-side provider options only).
• Platform item — no platform, packaging, updater, signing, paths, shell, or permissions surface touched.
• Docs/release/deps item — no docs, dependencies, generated files, or local file surfaces touched.

How To Verify

Red→green (worktree): with guard removed, new test fails — result.reasoningEffort === "medium"; with guard, it is undefined and reasoningSummary === "auto".
bun test test/provider/transform.test.ts: 205 pass, 0 fail
bun test (packages/opencode, full): 3669 pass, 9 skip, 1 todo, 0 fail (273 files)
bun run typecheck (turbo, all 9 packages): 8 successful, 0 errors

Screenshots or Recordings

N/A — no visible UI change.

Checklist

• Type label — this PR carries exactly one of bug, enhancement, task, documentation.
• Routing labels — this PR carries at least one of app, ui, platform, harness, ci.
• Priority label — this PR carries exactly one of P0, P1, P2, P3.
• Human Review Status above is set to Pending, Approved by @<reviewer>, or Not required: <reason>.
• I linked the related issue, or stated in Summary why there is no issue.
• I described the review focus and any meaningful risks.
• I replaced the example block in How To Verify with the real verification steps and the key result for each.
• I did not introduce unrelated refactors, dependencies, generated files, or file changes beyond the stated scope.
• (conditional) I manually checked visible UI or copy changes when needed, with screenshots or recordings. Leave unticked only if no visible UI or copy changed.
• (conditional) I considered macOS and Windows impact for platform, packaging, updater, signing, paths, shell, or permissions changes. Leave unticked only if no platform/packaging surface was touched.
• (conditional) I called out docs, release notes, dependencies, permissions, credentials, deletion behavior, generated content, or local file changes when relevant. Leave unticked only if none of those surfaces was touched.
• I reviewed the final diff for unrelated changes and suspicious dependency changes.
• I am targeting dev, and my PR title and commit messages use Conventional Commits in English.