# x402_call

Call any x402 paid API endpoint with automatic USDC payment via AgentCash. Accepts a full URL with query parameters. Handles the complete x402 payment flow: 1. Sends request → receives 402 payment requirement 2. Signs USDC payment on Base via AgentCash wallet 3. Retries with payment proof → returns endpoint data Requires AgentCash wallet to be set up and funded (https://agentcash.dev). Examples: - url:

Agent View of the PolicyLayer registry record for `x402_call`. HTML page: https://policylayer.com/tools/8randonpickart5-x402-buyer-mcp/x402-call

## Facts

- Tool: `x402_call`
- Server: X402 Buyer (`8randonpickart5/x402-buyer-mcp`) — https://policylayer.com/tools/8randonpickart5-x402-buyer-mcp.md
- Homepage: https://github.com/8randonpickart5/x402-buyer-mcp
- Risk category: Financial (Critical risk)
- Registry record: grade D, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Approval-gated

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "x402_call",
    "arguments": {}
  }
}
```

## Why x402_call is rated Critical

This tool autonomously initiates and completes real cryptocurrency (USDC) payments on the Base blockchain as part of its core operation. Every call to this tool can trigger an irreversible on-chain financial transaction. An AI agent misusing this tool (e.g., calling expensive endpoints repeatedly or with malicious URLs) could drain the funded wallet.

From the tool's own definition: "automatic USDC payment via AgentCash, Signs USDC payment on Base via AgentCash wallet, Handles the complete x402 payment flow"

## Use case

AI agents use x402_call to commit financial operations through X402 Buyer, usually the final step of a payment, billing, or trading workflow. A call moves real money.

## Recommended policy (PolicyLayer)

Verdict: **Approval-gated**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches X402 Buyer:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "x402_call": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}
```

## Other tools on X402 Buyer (3)

- `x402_research` — Execute — https://policylayer.com/tools/8randonpickart5-x402-buyer-mcp/x402-research.md
- `x402_balance` — Read — https://policylayer.com/tools/8randonpickart5-x402-buyer-mcp/x402-balance.md
- `x402_discover` — Read — https://policylayer.com/tools/8randonpickart5-x402-buyer-mcp/x402-discover.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=8randonpickart5-x402-buyer-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/8randonpickart5-x402-buyer-mcp