# Code Refactor with Diff and Rationale

> Code Refactor with Diff and Rationale is a paid API for AI agents from dev-5090-box.tailfb4c1f.ts.net, paid per call via x402, $0.03/call, status unknown (last checked 2026-10-12).

Refactors a code snippet while preserving its behavior, returning a diff and a written rationale explaining the changes.

## Facts

- Endpoint: POST https://dev-5090-box.tailfb4c1f.ts.net/v1/coder/refactor?utm_source=zero.xyz
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/code-refactor-with-diff-and-rationale-5ab9aaaf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GaHO4Q2ai2xj858m-7wrz

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability code-refactor-with-diff-and-rationale-5ab9aaaf -d '<json body>'
```

Example prompt: Refactor this Python function to be cleaner and more Pythonic — keep the behavior exactly the same and give me a diff plus a rationale explaining each change: def add(a, b): result = a + b; return result

## When to prefer this

Choose this endpoint when you need both a concrete diff and a human-readable rationale explaining refactoring decisions — not just a rewritten version. It's particularly useful for preparing code review materials, documenting technical debt cleanup, or understanding why changes were made. Prefer it over a generic code completion endpoint when behavioral preservation and auditability are the priority.

## Known failure modes

- Code snippet is too large or complex for the model context window
- Ambiguous or mixed-language snippets may produce incorrect diffs
- If the code has side effects that are hard to detect, behavioral preservation cannot be fully guaranteed
- Malformed or unparseable code may cause an empty or incorrect diff
- Model may occasionally hallucinate changes that subtly alter behavior in edge cases

## How this service works

Refactor code while preserving behavior. Returns diff + rationale.

## Output

Returns a diff showing exactly what lines changed and a written rationale explaining the reasoning behind each refactoring decision, while guaranteeing behavioral equivalence of the original code.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "usage": {
   "type": "object"
  },
  "choices": {
   "type": "array"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/code-refactor-with-diff-and-rationale-5ab9aaaf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dev-5090-box.tailfb4c1f.ts.net](https://www.zero.xyz/host/dev-5090-box.tailfb4c1f.ts.net/llms.txt)