MCP adapter

x402station-mcp

Stdio MCP server for x402station.io. It gives MCP-compatible clients pre-payment endpoint evidence before an agent signs PAYMENT-SIGNATURE. The adapter pays x402station routes with the wallet you provide; x402station does not custody funds or endorse target endpoints.

Install

# use directly from any MCP host
npx -y x402station-mcp

# or install globally
npm install -g x402station-mcp

Package: npm/x402station-mcp · Source: github.com/sF1nX/x402station-mcp · Registry: io.github.sF1nX/x402station

Configure

Set AGENT_PRIVATE_KEY to a wallet with Base mainnet USDC. Every paid tool call settles through x402; free status tools do not require a payment.

{
  "mcpServers": {
    "x402station": {
      "command": "npx",
      "args": ["-y", "x402station-mcp"],
      "env": {
        "AGENT_PRIVATE_KEY": "0xYOUR_PRIVATE_KEY_HERE"
      }
    }
  }
}

Agent Flow

# 1. discover the service contract
curl -s https://x402station.io/.well-known/mcp/server-card.json
curl -s https://x402station.io/.well-known/agent-card.json

# 2. preflight a target URL before paying it
curl -i -X POST https://x402station.io/api/v1/preflight \
  -H "content-type: application/json" \
  -d '{"url":"https://api.example.com/x402-endpoint"}'

# 3. after signing the x402station challenge, inspect the verdict
curl -s -X POST https://x402station.io/api/v1/preflight \
  -H "content-type: application/json" \
  -H "PAYMENT-SIGNATURE: <signed-x402station-payment>" \
  -d '{"url":"https://api.example.com/x402-endpoint"}'

If ok is false, do not pay the target endpoint. Call alternatives or ask for operator confirmation. Treat unknown_endpoint as no independent history, not as safety.

Tools

tool	price	purpose
`preflight`	$0.001	Endpoint risk before PAYMENT-SIGNATURE.
`preflight_batch`	$0.025	One settlement for up to 50 URLs.
`forensics`	$0.001	7-day probe and risk history for one URL.
`catalog_decoys`	$0.005	Current decoy / zombie / dead blacklist.
`alternatives`	$0.005	Healthy siblings for a blocked endpoint.
`whats_new`	$0.001	Catalog diff polling.
`buy_credits`	$0.50	1000 prepaid preflight calls.
`watch_subscribe`	$0.01	30-day webhook watch + 100 alerts.
`credits_status`	free	Credit balance lookup by creditId.
`watch_status`	free	Watch state lookup by id + secret.
`watch_unsubscribe`	free	Stop a watch by id + secret.

Related Surfaces

/llms.txt — autonomous flow and agent policy.
/skill.md — single-file agent skill.
/.well-known/agent-card.json — A2A-style discovery card with framework metadata.
/api/openapi.json — OpenAPI 3.1 for raw HTTP clients.