JSON Diff

Compare two JSON objects and list what was added, removed and changed, with paths and values.

Pay by wallet (x402) diff-json

Example

Example answer

{
  "added": [
    {
      "path": "/email",
      "value": "[email protected]"
    }
  ],
  "changed": [
    {
      "path": "/version",
      "new_value": 2,
      "old_value": 1
    }
  ],
  "removed": [],
  "identical": false,
  "added_count": 1,
  "changed_count": 1,
  "removed_count": 0
}

Inputs

Field	Type	Required	What it is
`after`	any	Yes	Modified JSON
`before`	any	Yes	Original JSON

Output fields

How reliably each field appears in a successful answer.

Field	Type	Appears
`added`	array	Always (present in every successful answer)
`changed`	array	Always (present in every successful answer)
`removed`	array	Always (present in every successful answer)
`identical`	boolean	Always (present in every successful answer)

How to call it

The same tool through each route. MCP clients reach it through Strale’s server at https://api.strale.io/mcp; the call below is what the agent sends.

# Needs an API key. max_price_cents caps what this call may cost.
curl -X POST https://api.strale.io/v1/do \
  -H "Authorization: Bearer $STRALE_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "capability_slug": "diff-json",
    "inputs": {
      "after": {
        "name": "Alice",
        "email": "[email protected]",
        "version": 2
      },
      "before": {
        "name": "Alice",
        "version": 1
      }
    },
    "max_price_cents": 3
  }'

{
  "tool": "strale_execute",
  "arguments": {
    "slug": "diff-json",
    "inputs": {
      "after": {
        "name": "Alice",
        "email": "[email protected]",
        "version": 2
      },
      "before": {
        "name": "Alice",
        "version": 1
      }
    },
    "max_price_cents": 3
  }
}

import { Strale } from "straleio";

const strale = new Strale({ apiKey: process.env.STRALE_API_KEY! });
const result = await strale.do({
  capability_slug: "diff-json",
  inputs: {
    "after": {
      "name": "Alice",
      "email": "[email protected]",
      "version": 2
    },
    "before": {
      "name": "Alice",
      "version": 1
    }
  },
  max_price_cents: 3,
});

import os
from straleio import Strale, DoRequest

strale = Strale(api_key=os.environ["STRALE_API_KEY"])
result = strale.do(DoRequest(
    capability_slug="diff-json",
    inputs={
        "after": {
            "name": "Alice",
            "email": "[email protected]",
            "version": 2,
        },
        "before": {
            "name": "Alice",
            "version": 1,
        },
    },
    max_price_cents=3,
))

# No account. The first request answers 402 with the price in USDC;
# an x402 client pays it from your wallet and repeats the request.
curl -i -X POST https://api.strale.io/x402/v2/diff-json \
  -H 'Content-Type: application/json' \
  -d '{
    "after": {
      "name": "Alice",
      "email": "[email protected]",
      "version": 2
    },
    "before": {
      "name": "Alice",
      "version": 1
    }
  }'

Limitations

Different value formats count as differences
Computes structural diff — semantically equivalent values in different formats (e.g., '1.0' vs 1) are reported as differences
What to do instead: Normalise number and boolean types before diffing if your data has mixed string/native representations

Related tools

JSON Schema Validation €0.02