codex_patch.cr

Crystal shard that implements the Codex patch format — a stripped-down, file-oriented diff format designed to be easy to parse and safe to apply, designed for use by LLMs.

Usage

1. Add the dependency to your shard.yml:

dependencies:
  codex_patch:
    github: nogginly/codex_patch.cr

2. Run shards install

3. Import the shard and use the top-level CodexPatch.apply method with with an IO (or String) to apply a patch to the current working directory.

require "codex_patch"

abort("Specify patch file, or - to read from standard inpput.") if ARGV.size.zero?

patch_file = ARGV.first
File.open(patch_file, "r") do |patch_io|
  cwd = Dir.current
  CodexPatch.apply(patch_io, cwd) do |event|
    puts event.inspect
  end
end

CLI

See DEVELOPMENT.md for how to build the CLI.

The included apply_codex_patch command applies a patch file to a target directory:

apply_codex_patch PATCH_FILE [ TARGET_DIR ]

Apply a codex patch to files in TARGET_DIR (defaults to the current directory).
PATCH_FILE must be a valid codex patch created by CodexPatch.

Patch file format

See ABOUT_PATCH_FORMAT.md

The document is intentionally separate so that you can give it to your LLM of choice to teach it how to write these patch files when using apply_codex_patch with your coding agent.

Contributions, by invitation!

With apologies, at this time contributions are by invitation only and limited to people I know and see often.

These are early days for codex_patch.cr and I am busy with family and work.

At this time I want to work on this at a manageable pace.