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Agent Card Validator (A2A) by Synthora
x402
Agent Card Validator (A2A) by Synthora is a paid API for AI agents from agentcard.hergertsynthora.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).
Validates an A2A Agent Card URL or JSON against the A2A specification, returning a compatibility score, schema errors, and warnings
Price / call$0.01
Success—
StatusUnknown
How this service works
Agent Card Validator (A2A): given an Agent Card URL or JSON, deterministically validates it against the A2A spec — required fields, skill schemas, endpoint reachability, security schemes, provider transparency — and returns a compatibility_score, schema_errors and warnings. The trust layer for the agent economy. Deterministic, Ed25519-signed. 0.01 USDC via x402 on Base. SYNTHORA.
Output
Returns a compatibility_score (numeric, Ed25519-signed), a list of schema_errors identifying spec violations (missing required fields, malformed skill schemas, invalid security schemes), and warnings for soft issues like provider transparency gaps and unreachable endpoints.
Example use cases
Example prompt
“Can you validate my A2A agent card at https://myagent.example.com/.well-known/agent-card.json and tell me the compatibility score, any schema errors, and whether my security scheme and endpoint are properly configured?”
Technical details
Endpoint
POSThttps://agentcard.hergertsynthora.com/serviceWhen to prefer
Use this endpoint when you need to deterministically validate an A2A Agent Card against the official spec before publishing or integrating it — especially when you need a signed compatibility score for trust verification, endpoint reachability confirmation, or skill schema compliance checking in the agent economy.
Side effects
- Invalid or unreachable URL returns endpoint reachability error
- Malformed JSON in card field returns parse error
- Agent card missing required fields returns schema_errors with details
- Network timeout on reachability check returns warning
- Payment not processed (x402) returns 402 response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| url | string | URL of the A2A Agent Card (.well-known/agent-card.json) |
| card | object | Or paste the Agent Card JSON directly |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"niche": "agent_card",
"result": {
"signed": "ed25519",
"verdict": "buena",
"warnings": [
"falta campo recomendado: documentationUrl"
],
"skills_count": 1,
"schema_errors": [],
"a2a_conformant": true,
"endpoint_status": 200,
"pricing_declared": false,
"security_declared": true,
"compatibility_score": 82
}
}
}Tags
x402
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