# A2A Agent Card Check

> A2A Agent Card Check is a paid API for AI agents from gogeta2-u35175.vm.elestio.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-28).

Fetch and validate a peer agent's A2A Agent Card (v1.0/v0.3), scoring it 0-100 with detailed field, skill, auth, signature, and reachability analysis.

## Facts

- Endpoint: GET https://gogeta2-u35175.vm.elestio.app/agents/v1/agent/a2a-card?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/a2a-agent-card-check-d5579a69
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mzn23K6nh1CiCObwQWDZ4

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability a2a-agent-card-check-d5579a69
```

Example prompt: Can you fetch and validate the A2A agent card at https://sabli.app and give me a score plus any issues you find with its fields, skills, auth, and reachability?

## When to prefer this

Choose this endpoint when you need to programmatically validate a peer agent's A2A Agent Card before integrating with it, onboarding it into a multi-agent system, or troubleshooting interoperability issues. It is purpose-built for A2A protocol compliance checking (v1.0 and v0.3) and provides a structured score plus actionable issues list — more thorough than a generic HTTP probe or MCP server check.

## Known failure modes

- URL unreachable or returns non-200 status — reachability failure reported in issues
- Agent card malformed JSON — parse error with details
- A2A card version unsupported — version mismatch flagged
- No agent card found at /.well-known/agent.json — card not found error
- Signature verification fails — cryptographic issue flagged in results
- Input URL missing or invalid format — 400 bad request

## How this service works

Fetch and validate a peer agent's A2A Agent Card (v1.0 / v0.3): fields, skills, interfaces, auth, signature, reachability. Score 0-100 + issues.

## Output

Returns a validation score from 0 to 100 along with a structured list of issues found in the agent card, covering field completeness, declared skills, interface definitions, authentication configuration, cryptographic signature validity, and network reachability of the agent endpoint.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "Agent base URL/domain or direct card URL, e.g. https://sabli.app"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/a2a-agent-card-check-d5579a69/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gogeta2-u35175.vm.elestio.app](https://www.zero.xyz/host/gogeta2-u35175.vm.elestio.app/llms.txt)