ChatGPT Official runs through Codex OAuth, so context accounting should follow
the Codex model catalog and its effective context window instead of public API
limits. This keeps GPT-5.5 at the same usable window shown by Codex while
preserving GPT-5.4's larger Codex window.
Constraint: Codex OAuth model metadata applies effective_context_window_percent to raw catalog windows
Rejected: Use public API GPT-5.5 1.05M context | Codex app and OAuth runtime clamp this model to the smaller effective window
Confidence: high
Scope-risk: narrow
Directive: Keep ChatGPT Official context values aligned to Codex model catalog behavior, not generic OpenAI API docs
Tested: bun test src/services/openaiAuth/models.test.ts src/services/compact/autoCompact.test.ts src/server/__tests__/providers.test.ts
Tested: bun run check:server
Tested: git diff --check
Not-tested: Manual desktop screenshot after rebuilding the app
Teach provider presets and saved providers to carry per-model context windows so auto-compact uses provider-specific limits instead of a blanket fallback. The desktop provider form now keeps these limits in an advanced context section and syncs the generated settings preview with model changes.
Constraint: Third-party provider APIs do not consistently expose machine-readable model context windows.
Rejected: Keep a single 100K/200K fallback | modern provider windows vary from 128K to 1M+ and the fallback caused late or early compaction.
Confidence: high
Scope-risk: moderate
Directive: Do not change provider compact thresholds without re-running real provider long-context checks.
Tested: bun test src/services/compact/autoCompact.test.ts; bun test src/server/__tests__/provider-presets.test.ts src/server/__tests__/providers.test.ts src/server/__tests__/providers-real.test.ts; bun run check:server; bun run check:desktop; bun run check:policy; bun run check:native; MiniMax/Kimi/DeepSeek live long-context probes; agent-browser provider form flow.
Not-tested: quality:pr policy gate still requires explicit allow-cli-core-change for CLI core edits.
