git:20260511.210285f to git:20260610.092f7c8
12 added, 11 removed. Audit A to A.
# builtin/gpt-apply-patch
- Builtin extension #4. When the active model is OpenAI GPT, swaps `write` / `edit` for a freeform Codex-style `apply_patch` tool with a Lark-style grammar. Applies multi-file patches (add / update / delete / move). Falls back to standard edit tools for non-GPT models. Largest single builtin (18 files).
+ Builtin extension #2. When the active model is a `gpt-*` model on a Responses-family API, swaps `write` / `edit` for a freeform Codex-style `apply_patch` tool with a Lark-style grammar. Applies multi-file patches (add / update / delete / move). Falls back to standard edit tools for all other models. Largest single builtin (18 files).
## FILES
```
gpt-apply-patch/
- ├── index.ts # Extension entry — model detection + tool registration
- ├── extension.ts # ExtensionAPI wiring (on model_select, on session_start)
+ ├── index.ts # Re-export barrel — the module's public surface, no logic
+ ├── extension.ts # Extension entry — API/model gate (isOpenAIGptModel) + tool registration;
+ │ # hooks session_start + model_select
├── tool.ts # `apply_patch` tool definition (TypeBox schema + execute)
├── params.ts # Argument parsing + validation
├── parser.ts # Codex apply_patch grammar parser
├── streaming-parser.ts # Streaming variant for partial-arg rendering during stream
├── streaming-render.ts # TUI render for partial patches
- ├── patch-diff.ts # Diff/hunk math (shared with `core/tools/edit-diff.ts`)
+ ├── patch-diff.ts # Diff/hunk math on top of the npm `diff` package
├── patch-replace.ts # Replace algorithms (anchor matching, seek fallback)
├── seek-sequence.ts # Strict context-line seek with N-line tolerance
├── apply.ts # Apply parsed patch to workspace
├── workspace.ts # File I/O + path normalization for patches
├── preview.ts # Preview before apply (used by permission-system parser)
├── preview-format.ts # Render preview as TUI nodes (opencode-style diff)
├── text.ts # Text utilities (line splitting, trailing newline handling)
├── constants.ts # Sentinel tokens (`*** Begin Patch`, `*** End Patch`, etc.)
├── errors.ts # Typed parse + apply errors
└── types.ts # Patch AST shape (FileOp union, Hunk, Replace)
```
## WHERE TO LOOK
| Task | File |
|------|------|
- | Fix a parse error from a real GPT output | `parser.ts` — add a fixture under `test/goldens/apply-patch/` |
+ | Fix a parse error from a real GPT output | `parser.ts` — add a regression test in `test/suite/gpt-apply-patch-extension.test.ts` |
| Improve strict-seek tolerance | `seek-sequence.ts` |
| Change render | `preview-format.ts` + `streaming-render.ts` |
| Add a new file op (e.g. `*** Rename File:`) | `types.ts` + `parser.ts` + `apply.ts` |
- | Adjust which models opt in | `index.ts` — model id pattern matching |
+ | Adjust which models opt in | `extension.ts` — `APPLY_PATCH_FREEFORM_APIS` + `gpt-` id prefix in `isOpenAIGptModel()` |
## CONVENTIONS
- - **GPT only**: this extension is dormant unless the active model is GPT-family. Other models keep `write`/`edit`. Selection happens on `model_select`.
+ - **Gate is API + id**: active only when `model.api` is in `APPLY_PATCH_FREEFORM_APIS` (`openai-responses`, `azure-openai-responses`, `openai-codex-responses`) AND `model.id` starts with `gpt-` — freeform custom tools only exist on the Responses-family APIs, so a `gpt-*` model on `openai-completions` keeps `write`/`edit`. Selection happens on `session_start` and `model_select`.
- **Strict context lines**: `seek-sequence.ts` requires exact context-line match (with bounded fuzz). Bypassing strict mode masks real grammar bugs.
- - **Mirror upstream Codex grammar** in `parser.ts` — the canonical reference is `openai/codex` `apply_patch` source. Tests pull goldens from there via `scripts/extract-codex-apply-patch-golden.mjs`.
+ - **Mirror upstream Codex grammar** in `parser.ts` — the canonical reference is `openai/codex` `apply_patch` source. The schema golden (`test/goldens/codex-apply-patch-schema.json`) is extracted from there via the repo-root `scripts/extract-codex-apply-patch-golden.mjs`.
- **Permission-system integration**: `parsers.ts` in `permission-system/` extracts file paths from patch bodies for per-file approval (see `permission-system/changes.md` 2026-04-13).
- **Render diffs like opencode** (recent commit f1d24c2f): the preview UI mirrors opencode's diff formatting.
## ANTI-PATTERNS
- Falling back to non-strict seek for "convenience" — masks model output bugs and produces wrong patches.
- - Hardcoding model IDs in `index.ts` — use pattern-matching against `model.id` so new GPT releases auto-opt-in.
- - Duplicating diff math here vs. `core/tools/edit-diff.ts` — `patch-diff.ts` should call into the shared module.
+ - Gating on a provider allowlist — gate on `model.api` + the `gpt-` id prefix in `extension.ts` so OpenAI-compatible custom providers (e.g. a proxy exposing gpt-5.5 via `openai-responses`) opt in too.
+ - Re-implementing diff rendering — `preview-format.ts` must keep using `core/tools/diff-render.ts` (`renderToolDiff`), the module shared with the `edit`/`write` renders.
- Changing patch sentinels (`*** Begin Patch`, etc.) — must match Codex exactly.
## NOTES
- The `apply_patch` tool exposes `promptSnippet` + `promptGuidelines` that the dynamic prompt picks up; prompt-preset's `file-operations.ts` reinforces "use apply_patch, not python heredoc" for GPT presets.
- - Goldens live under `packages/coding-agent/test/goldens/apply-patch/`. Re-extract from upstream via `npm run extract-codex-apply-patch-golden`.
+ - The schema golden lives at `packages/coding-agent/test/goldens/codex-apply-patch-schema.json` (consumed by `test/suite/regressions/codex-apply-patch-schema-parity.test.ts`). Re-extract from upstream with `node scripts/extract-codex-apply-patch-golden.mjs` at the repo root (requires a local `openai/codex` checkout).
- `streaming-parser.ts` powers partial render during model streaming — keep it tolerant of incomplete blocks.