pi-codex-apply-patch-wasm

A pi extension package that exposes the upstream Codex apply_patch WASM binary as an apply_patch tool, with Codex-style patch summaries and diff previews in the TUI.

Install

Local path:

pi install /absolute/path/to/pi-codex-apply-patch-wasm
pi install ./.pi/extensions/apply-patch

GitHub:

pi install git:github.com/trotsky1997/pi-codex-apply-patch-wasm

Project-local install:

pi install -l ./.pi/extensions/apply-patch

After install, restart pi or use /reload in an active session.

What it provides

• apply_patch tool compatible with the Codex patch envelope
• Codex-style path preparation before execution
• bundled apply_patch.wasm for standalone installs
• compact patch summaries in collapsed tool rows
• expanded diff previews for multi-file and code patches
• /apply-patch-selftest command to verify the WASM runner locally

Path handling

The extension now mirrors the upstream Codex path flow more closely before handing work to the bundled WASM runner:

• relative patch paths are kept as-is and resolved by the runner against the active cwd
• missing *** Begin Patch / *** End Patch lines are safely restored when the patch body is otherwise valid
• footer lines such as *** End Patch are normalized, and trailing chatty text after the footer is ignored
• absolute paths that stay inside the current cwd are rewritten back to relative paths before execution
• absolute paths outside the current cwd are rejected with a runner-specific error because this standalone WASM setup only preopens the current working directory
• *** End of File markers are preserved when a patch needs to be rewritten

This means the tool behaves closer to Codex for path normalization, while still making the WASM runner's sandbox limits explicit.

Development

The package prefers the bundled vendor/apply_patch.wasm. If that file is missing, it falls back to a local workspace build at:

• codex/codex-rs/target/wasm32-wasip1/release/apply_patch.wasm
• codex/codex-rs/target/wasm32-wasip1/debug/apply_patch.wasm

To refresh the bundled binary from this workspace build:

cp codex/codex-rs/target/wasm32-wasip1/debug/apply_patch.wasm .pi/extensions/apply-patch/vendor/apply_patch.wasm

Or use the bundled rebuild script and point it at an existing codex/codex-rs checkout:

./scripts/rebuild-codex-apply-patch-wasm.sh \
  --codex-rs-dir /path/to/codex/codex-rs \
  --wasi-sdk-dir /path/to/wasi-sdk-32.0-x86_64-linux

Run the focused path-handling smoke tests with:

npm test