Apply Patch

The opendunes:apply_patch helper is the building block of a coding agent. The model proposes a change to a file as a V4A diff; the diff is checked, and handed to your application, which applies it and reports back. Nothing is written to any file on our side.

It works on /v1/responses only. Named on another route, it answers 400.

Quick start#

curl https://opendunes.com/v1/responses \
  -H "Authorization: Bearer $OPENDUNES_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5.6-luna",
    "input": "Rename the function calcTotal to computeTotal in src/cart.js.",
    "tools": [{ "type": "opendunes:apply_patch" }]
  }'

The loop#

1. The model decides a file must be created, changed or deleted, and writes a diff.
2. The diff's syntax is checked. A malformed diff goes back to the model to correct.
3. A valid diff reaches you as an apply_patch_call output item, its operation one of create_file, update_file, delete_file.
4. Your application applies it — or refuses — and sends the outcome back on the next turn as an apply_patch_call_output input item.

Parameters#

Billing#

No charge beyond the model's tokens.