---
title: "A2A Agent Card Validator & Extension Checker"
method: POST
path: "/v1/tools/validate_a2a_agent_card"
tags: ["A2A", "Agent2Agent", "agent card", "signed agent card", "AP2", "capability discovery"]
---

# A2A Agent Card Validator & Extension Checker

`POST /v1/tools/validate_a2a_agent_card`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/validate_a2a_agent_card`
- Auth: none declared

Validates an Agent2Agent (A2A) agent-card.json against the v1.0 shape, checks the signed-card signatures block, and confirms AP2 / x402 extension declarations. Field names reflect A2A v1.0 — verify against the A2A schema. Does not perform cryptographic signature verification.

**Tool URL:** https://ainumbers.co/tools/283-a2a-agent-card-validator.html
**AP2/Policy Mandate export:** yes

## Request body

- object
  - `agent_card` object, required: The A2A agent-card.json document

## Response `200`

Successful tool execution result

- object
  - `score` number
  - `findings` unknown[]
    - unknown

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)