# Verification Agent A2A Message Send

> Verification Agent A2A Message Send is a paid API for AI agents from verification-agent-a2a.d-mueller.workers.dev, paid per call via x402, $0.050000/call, status unknown (last checked 2026-09-14).

Sends an A2A (Agent-to-Agent) protocol message to a verification agent for processing verification tasks

## Facts

- Endpoint: GET https://verification-agent-a2a.d-mueller.workers.dev/message:send
- Price: $0.050000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/verification-agent-a2a-message-send-d25165dd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BI4xcYDJuqEpSuHB9-JfP

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 verification-agent-a2a-message-send-d25165dd
```

Example prompt: Send a message to the verification agent asking it to verify that the following claim is accurate: 'The Eiffel Tower is located in Paris, France' — use the user role and text part kind.

## When to prefer this

Choose this endpoint when you need to interact with a dedicated verification agent using the A2A (Agent-to-Agent) protocol, particularly for validating claims, checking facts, or confirming information. Prefer this over generic HTTP APIs when you want structured agent-to-agent communication with a verification-focused AI. Best suited for workflows that require verifiable confirmation of content accuracy.

## Known failure modes

- Missing required 'role' field in message object returns validation error
- Missing required 'parts' array or empty parts array causes rejection
- Invalid 'kind' enum value (must be 'text') causes schema validation failure
- Payment of $0.05 USDC not provided results in 402 Payment Required response
- Malformed message structure causes agent processing error
- Agent unavailable or overloaded returns 503 error

## How this service works

Send an A2A message to the verification agent.

## Output

The verification agent processes the A2A message and returns a response containing the verification outcome, status, or result based on the content submitted in the message parts.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "message": {
   "type": "object",
   "required": [
    "role",
    "parts"
   ],
   "properties": {
    "role": {
     "type": "string"
    },
    "parts": {
     "type": "array",
     "items": {
      "type": "object",
      "required": [
       "kind",
       "text"
      ],
      "properties": {
       "kind": {
        "enum": [
         "text"
        ],
        "type": "string"
       },
       "text": {
        "type": "string"
       }
      },
      "additionalProperties": true
     }
    }
   },
   "additionalProperties": true
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/verification-agent-a2a-message-send-d25165dd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from verification-agent-a2a.d-mueller.workers.dev](https://www.zero.xyz/host/verification-agent-a2a.d-mueller.workers.dev/llms.txt)