Add x402 payment execution to AI agents with per-task budgets, spending controls, and non-custodial wallets. Supports Base through agentwallet-sdk and X Layer through OKX Payments / OKX Agent Payments Protocol. Use when an agent must pay for something itself and needs per-task budgets, spending cont

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: Need Recommended path Agent pays a 402 gated API on Base or another agentwallet supported chain Use agentwallet sdk as an MCP payment server with strict spending policy Agent pays a 402 gated API on X Layer Use OKX Agent Payments Protocol from okx/onchainos skills ; okx x402 payment is a deprecated legacy alias TypeScript API charges agents Use OKX Payments TypeScript seller SDK docs for Express, Hono, Fastify, or Next.js Go API charges agents Use OKX Payments Go seller SDK docs for Gin, Echo, or net/http Rust API charges agents Use OKX Payments Rust seller SDK docs for Axum Java API charges agents Use OKX Payments Java seller SDK docs for Spring Boot 2/3, Java EE, or Jakarta Python API charges agents Check the current OKX Payments repository before implementation; a Python seller guide may not be available 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. 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) Available Tools (agent callable) Tool Purpose get balance Check agent wallet balance send payment Send payment to address or ENS check spending Query remaining budget list transactions Audit trail of all payments Note : Spending policy is set by the orchestrator before delegating to the agent — not by the agent itself. This prevents agents from escalating their own spending limits. Configure policy via set policy in your orchestration layer or pre task hook, never as an agent callable tool. Option B: OKX Agent Payments Protocol (X Layer) Use this path for X Layer x402, Multi Party Payment (MPP), session payment, charge, and A2A charge flows. For buyer side agent flows: 1. Install or reference the current okx/onchainos skills repository. 2. Use skills/okx agent payments protocol/SKILL.md as the dispatcher. 3. Treat skills/okx x402 payment/SKILL.md as a deprecated compatibility alias, not as the canonical skill. 4. Require explicit user confirmation before wallet status checks or payment actions. Do not hide payment execution behind a generic tool call. For seller side API flows, fetch the latest language specific guide before generating code: Runtime Current guide TypeScript https://raw.githubusercontent.com/okx/payments/main/typescript/SELLER.md Go https://raw.githubusercontent.com/okx/payments/main/go/x402/SELLER.md Rust https://raw.githubusercontent.com/okx/payments/main/rust/x402/SELLER.md Java https://raw.githubusercontent.com/okx/payments/main/java/SELLER.md Do not copy examples from older docs without checking the current OKX repository. Current OKX guidance uses okx agent payments protocol as the dispatcher, and Java seller docs are now available. Examples Budget enforcement in an MCP client When building an orchestrator that calls the agentpay MCP server, enforce budgets before dispatching paid tool calls. Prerequisites : Install the package before adding the MCP config — npx without y will prompt for confirmation in non interactive environments, causing the server to hang: npm install g agentwallet sdk@6.0.0 Best Practices Set budgets before delegation : When spawning sub agents, attach a SpendingPolicy via your orchestration layer. Never give an agent unlimited spend. Pin your dependencies : Always specify an exact version in your MCP config (e.g., agentwallet sdk@6.0.0 ). Verify package integrity before deploying to production. Audit trails : Use list transactions in post task hooks to log what was spent and why. Fail closed : If the payment tool is unreachable, block the paid action — don't fall back to unmetered access. Pair with security review : Payment tools are high privilege. Apply the same scrutiny as shell access. Test with testnets first : Use Base Sepolia for development; switch to Base mainnet for production. Production Reference npm : [ agentwallet sdk ](https://www.npmjs.com/package/agentwallet sdk) Merged into NVIDIA NeMo Agent Toolkit : [PR 17](https://github.com/NVIDIA/NeMo Agent Toolkit Examples/pull/17) — x402 payment tool for NVIDIA's agent examples Protocol spec : [x402.org](https://x402.org) OKX Payments SDKs : [ okx/payments ](https://github.com/okx/payments) — TypeScript, Go, Rust, and Java seller integrations for X Layer x402 OKX Agent Payments Protocol skill : [ okx/onchainos skills ](https://github.com/okx/onchainos skills/tree/main/skills/okx agent payments protocol) OKX Payments overview : [web3.okx.com/onchainos/dev docs/payments/overview](https://web3.okx.com/onchainos/dev docs/payments/overview)

agent-payment-x402