agentpatch

agentpatch is a tiny toolkit + conventions for applying AI-generated patches safely and repeatably.

bin/apply_patch

A robust patch applier that supports a simplified, explicit patch grammar:

• *** Begin Patch / *** End Patch
• *** Update File: path
• *** Add File: path
• *** Delete File: path (requires --allow-delete)
• *** Rename File: old -> new (requires --allow-rename)
• @@ ... @@ hunks containing lines prefixed with:
  • - remove
  • + add
  • context

Anchors

Inside the @@ ... @@ header you can include anchor directives:

• @@ at:top @@
• @@ at:bottom @@
• @@ before:/regex/ @@
• @@ after:/regex/ @@

If a - block can’t be found, anchors provide a deterministic insertion location.

Idempotence

If the + block already exists (exact or whitespace-insensitive match), the hunk is treated as already applied.

Usage

bin/apply_patch --verbose <<'PATCH'
*** Begin Patch
*** Add File: hello.txt
+hello\n
*** End Patch
PATCH

License

MIT

Tests

Run a small gauntlet against bin/apply_patch:

node tests/run-tests.mjs

# or point at a different apply_patch implementation
APPLY_PATCH=/path/to/bin/apply_patch node tests/run-tests.mjs