# Diff two JSON documents from an AI agent

You need the exact list of differences between two JSON values, for example two API responses or two versions of a config.

**Use `json-deep-diff@1.0.0`.** It is free and needs no key or sign-up. Bounded deterministic JSON difference records. Not a JSON Patch implementation.

## Why call a tool for this

Each difference comes back with a JSON Pointer path and the values involved: left and right for a replace, right for an add, left for a remove. That makes it simple to quote in a report or to act on one change at a time.

## Call it over HTTP

```sh
curl -X POST https://computefirst.net/v1/tools/json-deep-diff/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"a":{"x":1,"y":2},"b":{"x":1,"y":3,"z":4}}'
```

Response:

```json
{
  "result": {
    "changes": [
      {
        "pointer": "/y",
        "op": "replace",
        "left": 2,
        "right": 3
      },
      {
        "pointer": "/z",
        "op": "add",
        "right": 4
      }
    ]
  }
}
```

## Call it over MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "json-deep-diff",
  "version": "1.0.0",
  "input": {
    "a": {
      "x": 1,
      "y": 2
    },
    "b": {
      "x": 1,
      "y": 3,
      "z": 4
    }
  }
}
```

## Check the result

The output is a list of difference records, not a JSON Patch document. To only test whether two values are equal, use the equality tool instead.

Full contract, limits and unsupported cases: [JSON deep diff](/tools/json-deep-diff).

## Related tools

- [JSON deep equal](/tools/json-deep-equal)