# Configure X402 > Configure x402 micropayments for agent-to-agent commerce via Uniswap. Set up your agent to pay per MCP request in USDC on Base (~200ms settlement) or accept x402 payments as a service provider. Use when the user wants to enable pay-per-use API access or monetize their agent's services. - Skill: `johnalbertini14-glitch/configure-x402` (Agent Skill, multi-file: 3 files) - Install (CLI): `npx skillmds@latest add johnalbertini14-glitch/configure-x402` - Raw SKILL.md: https://api.skillmd.com/api/skills/johnalbertini14-glitch/configure-x402/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: johnalbertini14-glitch (https://skillmd.com/u/johnalbertini14-glitch) - Updated: 2026-09-09 - Page: https://skillmd.com/skills/johnalbertini14-glitch/configure-x402 --- # Configure x402 ## Overview Configures the x402 HTTP-native payment protocol for agent-to-agent micropayments settled on Base. x402 uses the HTTP 402 "Payment Required" status code to enable pay-per-request billing — agents pay fractions of a cent per API call in USDC, with ~200ms settlement, no API keys, no accounts, and no subscriptions. This skill supports two modes: - **Pay mode**: Configure your agent to pay for MCP tool calls and external API access via x402 - **Accept mode**: Configure your agent as an x402 service provider that accepts micropayments for its services - **Both**: Enable bidirectional x402 payments x402 has processed 100M+ agent-to-agent transactions across 80+ ecosystem projects (Feb 2026). It eliminates API key onboarding friction and creates revenue streams from every agent interaction. ## When to Use Activate when the user says: - "Set up x402 payments for my agent" - "Enable pay-per-swap via x402" - "Configure my agent to accept x402 payments" - "Set up micropayments on Base" - "Enable x402 for my MCP server" - "Monetize my agent's API" - "Configure pay-per-request billing" - "Set up agent-to-agent payments" ## Parameters | Parameter | Required | Default | Description | |-------------------|----------|-------------|-------------------------------------------------------------------------------------------------------| | `mode` | No | both | Payment mode: "pay" (pay for services), "accept" (accept payments), or "both" | | `walletAddress` | Yes | -- | USDC wallet address on Base for sending/receiving payments | | `chain` | No | base | Settlement chain (Base recommended for ~200ms settlement) | | `pricePerCall` | No | see pricing | Price per MCP tool call in USDC (for accept mode). Defaults to recommended pricing below. | | `supportedTools` | No | all | Which MCP tools to gate behind x402 payments (for accept mode). "all" or comma-separated list. | | `maxSpendPerHour` | No | $1.00 | Maximum x402 spend per hour (for pay mode). Safety limit to prevent runaway costs. | | `facilitator` | No | auto | x402 facilitator to use. "auto" selects the best available facilitator on Base. | ### Recommended Pricing (Accept Mode) | Tool Category | Price per Call | Examples | |--------------------|----------------|-------------------------------------------------| | Price quotes | $0.001 | `get_token_price`, `get_quote` | | Pool analytics | $0.003 | `get_pool_info`, `get_pool_volume_history` | | Route optimization | $0.005 | `get_pools_by_token_pair`, `search_tokens` | | Simulation | $0.01 | `simulate_transaction` | | Execution | $0.05 | `execute_swap`, `add_liquidity` | ## Workflow 1. **Parse configuration** from the user's request. Determine the payment mode, wallet address, chain, pricing, and tool scope. Validate the wallet address format. 2. **Validate wallet**: Verify the wallet address exists on the target chain and has a USDC balance (for pay mode) or can receive USDC (for accept mode). Check that the chain supports x402 settlement. 3. **Write x402 configuration**: Generate the x402 configuration file at `.uniswap/x402-config.json` with: - Payment mode (pay/accept/both) - Wallet address and chain - Facilitator endpoint - Per-tool pricing (accept mode) - Spending limits (pay mode) - Supported tools list For accept mode, also generate the `.well-known/x402-manifest.json` that advertises the agent's x402-enabled endpoints to other agents. 4. **Verify setup**: Confirm the configuration is valid by checking: - Wallet connectivity on the settlement chain - Facilitator availability - USDC token approval for the facilitator contract (if pay mode) - Configuration file is properly formatted ## Output Format ```text x402 Configuration Complete Mode: Both (pay + accept) Chain: Base (8453) Wallet: 0x1234...abcd Facilitator: Auto-selected (Coinbase x402) Pay Mode: Max Spend: $1.00/hour USDC Balance: $50.00 (sufficient) Accept Mode: Pricing: Price quotes: $0.001/call Pool analytics: $0.003/call Route optimization: $0.005/call Simulation: $0.010/call Execution: $0.050/call Tools Gated: All (17 tools) Config Files: .uniswap/x402-config.json .well-known/x402-manifest.json Status: Ready for x402 payments ``` ## Important Notes - x402 settles on Base by default (~200ms). Ethereum mainnet settlement is possible but slower and more expensive. - USDC is the only supported payment token for x402. The wallet must hold USDC on the settlement chain. - The `maxSpendPerHour` safety limit prevents runaway costs in pay mode. Adjust based on expected usage. - x402 uses the HTTP 402 "Payment Required" status code. When a client hits an x402-gated endpoint without payment, it receives a 402 response with payment instructions. - Facilitators handle the payment settlement. The "auto" option selects the best available facilitator on the target chain. - For accept mode, the `.well-known/x402-manifest.json` file makes your agent discoverable on Coinbase Bazaar (12,365+ services). - x402 payments are per-request. There are no subscriptions, API keys, or accounts. Each request includes a micropayment. - All x402 transactions are logged for treasury management and can be tracked via the `manage-treasury` skill. - This skill does not execute any on-chain transactions. It only generates configuration files. The actual x402 payment flow happens at runtime when the MCP server processes requests. ## Error Handling | Error | User-Facing Message | Suggested Action | |------------------------|----------------------------------------------------------------------------|-----------------------------------------------| | Invalid wallet | "Invalid wallet address format." | Provide a valid Ethereum address (0x...) | | No USDC balance | "Wallet has no USDC on [chain]. x402 payments require USDC." | Fund the wallet with USDC on Base | | Chain not supported | "[chain] does not support x402 settlement." | Use Base (recommended) or Ethereum | | Facilitator unavailable| "No x402 facilitator available on [chain]." | Try Base (most facilitators available) | | Config write failed | "Could not write x402 configuration: [reason]." | Check file permissions | | Wallet not configured | "No agent wallet found. Set up a wallet first." | Use `setup-agent-wallet` skill first | | Invalid pricing | "Price per call must be positive and in USDC." | Provide valid pricing values |