| name | configure-x402 |
| description | 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. |
| model | sonnet |
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
-
Parse configuration from the user's request. Determine the payment mode, wallet address, chain, pricing, and tool scope. Validate the wallet address format.
-
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.
-
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.
-
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
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 |
