Agent Payment Execution (x402)

Enable AI agents to make policy-gated payments with built-in spending controls. Uses the x402 HTTP payment protocol and MCP tools so agents can pay for external services, APIs, or other agents without custodial risk.

When to Use

Use when: your agent needs to pay for an API call, purchase a service, settle with another agent, enforce per-task spending limits, or manage a non-custodial wallet. Pairs naturally with cost-aware-llm-pipeline and security-review skills.

Decision Tree

Choose the integration path based on whether your agent is buying access to a paid API or charging others for one:

Supported Networks

• agentwallet-sdk: use the package docs to confirm current network coverage before production. Base Sepolia is the safest development default; Base mainnet is the production path called out by the original skill.
• OKX Payments / X Layer: current seller docs target X Layer (eip155:196) and USDT0 settlement. Fetch current SDK docs before generating production code because payment packages and facilitator behavior can change quickly.
• Upstream x402 packages: multi-network by design — one route can advertise Base and Solana simultaneously and let the buyer pick. The packages default to the x402.org facilitator, which is testnet-only (Base Sepolia eip155:84532, Solana devnet solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1, plus Stellar, Aptos, Hedera, and XRPL testnets) and is not intended for mainnet routes. For mainnet (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp for Solana), either self-facilitate, run your own facilitator, or pick a hosted one from the upstream facilitator list — see the facilitator comparison under Option C. Confirm live coverage at the facilitator's /supported endpoint before production rather than hardcoding it here.

How It Works

x402 Protocol

x402 extends HTTP 402 (Payment Required) into a machine-negotiable flow. When a server returns 402, the agent's payment tool negotiates price, checks budget, signs a transaction, and retries only inside the policy and confirmation boundary set by the orchestrator.

Spending Controls

Every payment tool call enforces a SpendingPolicy:

• Per-task budget — max spend for a single agent action
• Per-session budget — cumulative limit across an entire session
• Allowlisted recipients — restrict which addresses/services the agent can pay
• Rate limits — max transactions per minute/hour

Non-Custodial Wallets

Agents hold their own keys via ERC-4337 smart accounts. The orchestrator sets policy before delegation; the agent can only spend within bounds. No pooled funds, no custodial risk.

MCP Integration

The payment layer exposes standard MCP tools that slot into any Claude Code or agent harness setup.

Security note: Always pin the package version. This tool manages private keys — unpinned npx installs introduce supply-chain risk.

Option A: agentwallet-sdk (Base / multi-chain)

{
  "mcpServers": {
    "agentpay": {
      "command": "npx",

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