Compare two agent run sequences and see how their tool calls differ
Compare two agent run sequences and see how their tool calls differ. Send before and after arrays of tool calls (name/args or tool/arguments shape) and get back which calls were added, removed, or reordered, plus per-call argument drift with the exact changed argument paths from a deep compare. The result is exact and reproducible: the same replay comparison always returns the same diff. Built for agent regression diff work: confirming a prompt or code change didn't silently alter which tools an agent calls or what it passes them. Use it as a tool call diff API, an agent action drift checker, or a replay comparison step in CI before shipping an agent change.
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://x402.agentutility.ai/tool-call-diff
| Category | Code and developer |
|---|---|
| Provider host | x402.agentutility.ai |
| Networks | eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"body": {
"after": [
{
"args": {
"limit": 10,
"q": "world"
},
"name": "search"
},
{
"args": {
"url": "https://example.com"
},
"name": "fetch"
}
],
"before": [
{
"args": {
"limit": 10,
"q": "hello"
},
"name": "search"
},
{
"args": {
"url": "https://example.com"
},
"name": "fetch"
}
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"after": {
"description": "The new tool-call sequence to compare against 'before', same shape. Required, max 500 entries.",
"type": "array"
},
"before": {
"description": "The baseline tool-call sequence: a JSON array of call objects, each shaped {name, args} (or {tool, arguments} / {tool_name, input}). Required, max 500 entries.",
"type": "array"
}
},
"required": [
"before",
"after"
]
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"added": {
"type": "array"
},
"after_count": {
"type": "integer"
},
"arg_drifted": {
"items": {
"properties": {
"arg_diffs": {
"items": {
"properties": {
"after": {
"type": "string"
},
"before": {
"type": "string"
},
"path": {
"type": "string"
}
},
"type": "object"
},
"type": "array"
},
"index_after": {
"type": "integer"
},
"index_before": {
"type": "integer"
},
"name": {
"type": "string"
}
},
"type": "object"
},
"type": "array"
},
"before_count": {
"type": "integer"
},
"identical": {
"type": "boolean"
},
"removed": {
"type": "array"
},
"reordered": {
"type": "array"
},
"unchanged_count": {
"type": "integer"
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}