Agent Discovery

Overview

50c supports agent discovery via the Agent-to-Agent (A2A) protocol and OpenAPI spec.

A2A Agent Card

The Agent Card is at:

https://50c.ai/.well-known/agent.json
https://api.50c.ai/.well-known/agent.json

Structure

{
  "name": "50c AI Tools",
  "description": "101+ AI developer tools. Math, code, scraping, UX, security.",
  "url": "https://50c.ai",
  "version": "1.0.0",
  "capabilities": [
    { "name": "math", "description": "Mathematical reasoning" },
    { "name": "code", "description": "Code generation and review" },
    { "name": "scraping", "description": "Web scraping" },
    { "name": "ux", "description": "UX analysis" },
    { "name": "security", "description": "Supply chain verification" }
  ],
  "endpoints": {
    "mcp": "https://api.50c.ai/mcp",
    "rest": "https://api.50c.ai/tools",
    "openapi": "https://api.50c.ai/openapi.json",
    "x402": "https://api.50c.ai/tools"
  },
  "payment_protocols": ["api_key", "x402", "mpp"],
  "pricing_model": "per_call",
  "price_range": { "min_cents": 0, "max_cents": 2000 },
  "free_tools": 23,
  "total_tools": 101,
  "docs": "https://docs.50c.ai"
}

OpenAPI Spec

The OpenAPI 3.1 spec is at:

https://api.50c.ai/openapi.json

Usage

LangChain example:

from langchain.agents import load_tools

tools = load_tools(
    openapi_spec="https://api.50c.ai/openapi.json",
    api_key="cv_YOUR_KEY"
)

CrewAI example:

from crewai import Agent

agent = Agent(
    role="Math Expert",
    tools=load_50c_tools(api_key="cv_YOUR_KEY")
)

Discovery Flow

1. Agent fetches /.well-known/agent.json
2. Agent reads available capabilities
3. Agent fetches /openapi.json for detailed tool schemas
4. Agent calls tools via preferred endpoint

Payment Negotiation

The Agent Card includes supported payment protocols:

Protocol	Auth Method
api_key	Bearer token
x402	HTTP 402 + USDC
mpp	Session token

Agents can choose their preferred payment method.

MCP Registry

50c is registered in Anthropic’s MCP Registry:

{
  "name": "50c",
  "description": "101+ AI developer tools",
  "repository": "https://github.com/genxis/50c",
  "npm_package": "50c",
  "tools_count": 101
}

CORS

All discovery endpoints include CORS headers:

Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, OPTIONS