# Agent Verification Utility A2A Agent

**Canonical:** https://apis.io/apis/kgninja-dev/agent-verification-utility-a2a-agent/  
**Provider:** KG-NINJA — https://apis.io/providers/kgninja-dev/  
**Base URL:** https://agent-economy.kgninja.dev/a2a  
**Documentation:** https://agent-economy.kgninja.dev/docs/mcp-x402-interoperability

Agent Verification Utility A2A Agent is one of 3 APIs that [KG-NINJA](https://apis.io/providers/kgninja-dev/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include A2A, Agent-Native, and x402.

Agent2Agent (A2A) 1.0 surface: an agent card served from https://agent-economy.kgninja.dev/.well-known/agent-card.json (supportedInterfaces[] JSONRPC at https://agent-economy.kgninja.dev/a2a, protocolVersion 1.0, version 0.4.3, provider KG-NINJA) declaring one skill, prepare-json-evidence-verification, which revalidates a prechecked paid intent, creates or reuses an idempotent bound quote and returns exact x402 and MCP purchase instructions as a direct Message. The adapter is stateless and synchronous: it never creates Tasks, never executes paid work, and declares streaming, push notifications and extended cards unsupported. The endpoint enforces the A2A-Version header (0.3 is rejected with -32009 VERSION_NOT_SUPPORTED; 1.0 is required).

## Machine-readable artifacts (2)

- **AgentCard** — https://raw.githubusercontent.com/api-evangelist/kgninja-dev/refs/heads/main/a2a/kgninja-dev-a2a.yml
- **AgentCard** — https://agent-economy.kgninja.dev/.well-known/agent-card.json

## Other KG-NINJA APIs (2)

- [Agent Verification Utility API](https://apis.io/apis/kgninja-dev/agent-verification-utility-api/)
- [Agent Verification Utility MCP Server](https://apis.io/apis/kgninja-dev/agent-verification-utility-mcp-server/)

## Tags

A2A, Agent-Native, x402

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/kgninja-dev/agent-verification-utility-a2a-agent/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/kgninja-dev/.