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FastX402 JSON Semantic Diff
x402
FastX402 JSON Semantic Diff is a paid API for AI agents from fastx402.tools, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).
Compares two JSON objects or arrays and returns a structured semantic diff showing added, removed, and modified fields with their paths and values.
Price / call$0.002
Success—
StatusUnknown
How this service works
200 pay-per-call tools for AI agents, from $0.001 per request in USDC on Base or Solana with x402. No account, no API key.
Output
A JSON object listing added fields (path + new value), removed fields (path + old value), and modified fields (path + before value + after value), plus a human-readable summary string such as '2 modified, 1 added, 1 removed'.
Example use cases
API response change detection
“I have two versions of an API response and I need to know exactly what changed — before: {"price":99,"inStock":true,"label":"Basic"} and after: {"price":109,"inStock":true,"label":"Standard","discount":0.1}. Can you diff them semantically?”
Config file drift tracking
“My deployment config changed between releases. Before it was {"replicas":2,"env":"staging","debug":true} and now it's {"replicas":4,"env":"production","debug":false,"timeout":30}. What are all the differences?”
User profile update audit
“A user's profile record was updated. Can you compare the old version {"name":"Alice","role":"viewer","active":false} with the new one {"name":"Alice","role":"editor","active":true,"verified":true} and summarize what changed?”
Technical details
Endpoint
GEThttps://fastx402.tools/json-diff-semantic?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need a structured, path-level semantic diff of two JSON objects or arrays — especially when you want to programmatically consume the diff (added/removed/modified lists with field paths) rather than a raw text comparison. Prefer this over generic text diff tools when working with API payloads, config objects, or any structured data where field-level change tracking matters.
Side effects
- Malformed JSON in 'before' or 'after' params causes parse error
- Missing required 'before' or 'after' query parameters returns validation error
- Very large or deeply nested JSON may hit size limits
- Non-JSON strings passed as parameters return error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"added": [
{
"path": "status",
"value": "active"
}
],
"removed": [
{
"path": "active",
"value": true
}
],
"summary": "2 modified, 1 added, 1 removed",
"modified": [
{
"path": "age",
"after": 31,
"before": 30
},
{
"path": "tags[1]",
"after": "moderator",
"before": "user"
}
]
}
}Tags
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