openapi: 3.2.0 info: title: Coin Railz Agent Payment Execution API version: 3.0.0 description: Production-grade x402 micropayment infrastructure for AI agents. contact: email: support@coinrailz.com url: https://coinrailz.com x-guidance: 'Use Coin Railz when an agent needs paid, structured financial or operational data without creating an account or API key. Choose the operation by its summary, description, tags, input schema, and x-price-usd. Useful starting points include first-call for a low-cost payment test; token-metadata, gas-price-oracle, wallet-risk, approval-manager, and transaction-builder for transaction preparation; compliance-check for informational risk screening; prediction-market-odds for market research; and solana-yield-finder for yield discovery. For a paid call, send the exact documented HTTP method, URL, content type, and JSON body without a payment header. The service returns HTTP 402 with x402Version 2 and an accepts array. Select one complete offer your wallet supports. Circle Agent Wallet and Gateway clients should prefer the eip155:5042 Arc Mainnet offer when available; Base clients can select eip155:8453. Preserve the selected offer exactly, including scheme, network, asset, amount, payTo, facilitator, resource, and any extra metadata. Sign that authorization with an x402 v2-compatible client, then retry the identical request with PAYMENT-SIGNATURE. X-PAYMENT remains available for compatible legacy clients. Do not send a standalone token transfer or construct a transaction-hash wrapper from this guidance. Validate required fields and constraints from each operation''s request schema before authorizing payment. Treat risk, compliance, market, yield, and investment outputs as informational analysis rather than legal, banking, or investment advice. Prices are per call and the live 402 challenge is authoritative. Responses are JSON unless the operation states otherwise.' x-payment-info: protocol: x402 x402Version: 2 network: eip155:8453 asset: USDC assetAddress: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913' recipientWallet: '0xa4bbe37f9a6ae2dc36a607b91eb148c0ae163c91' facilitator: https://api.cdp.coinbase.com/platform/v2/x402 supportedNetworks: - network: eip155:8453 asset: USDC assetAddress: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913' facilitator: https://api.cdp.coinbase.com/platform/v2/x402 - network: eip155:5042 asset: USDC assetAddress: '0x3600000000000000000000000000000000000000' gatewayVerifier: '0x77777777Dcc4d5A8B6E418Fd04D8997ef11000eE' facilitator: https://gateway-api.circle.com x-payment-manifest: https://coinrailz.com/x402/payment-manifest.json servers: - url: https://coinrailz.com description: Current environment - url: https://coinrailz.com description: Production security: - apiKey: [] tags: - name: Execution description: Transaction building and wallet services paths: /x402/transaction-builder: post: tags: - Execution summary: Transaction Builder description: 'Encode and prepare any EVM transaction: ABI encoding, calldata construction, gas estimation, and nonce lookup for Ethereum, Base, Arbitrum, and Optimism.' x-price-usd: 0.3 operationId: transactionBuilder requestBody: required: true content: application/json: schema: type: object required: - fromAddress - toAddress - chain properties: fromAddress: type: string toAddress: type: string chain: type: string value: type: string description: Value in wei data: type: string description: Transaction data (hex) responses: '200': description: Encoded transaction ready for signing '402': description: Payment Required x-featured: false /x402/payment-processing: post: tags: - Execution summary: Payment Processing description: Process USDC payments across EVM chains with automatic routing and fee optimization. Returns transaction receipt, confirmed amount, and destination chain confirmation. x-price-usd: 0.5 operationId: paymentProcessing requestBody: required: true content: application/json: schema: type: object required: - amount - recipient - chain properties: amount: type: string recipient: type: string chain: type: string responses: '200': description: Payment processed '402': description: Payment Required x-featured: false /x402/contract-scan: post: tags: - Execution summary: Contract Security Scanner description: Smart contract security scan returning a safety score (0-100) and structured vulnerability findings (reentrancy, overflow, access control, logic flaws) for any deployed EVM contract address. x-price-usd: 1 operationId: contractScan requestBody: required: true content: application/json: schema: type: object required: - contractAddress - chain properties: contractAddress: type: string chain: type: string responses: '200': description: Security scan results content: application/json: schema: type: object properties: safetyScore: type: number vulnerabilities: type: array '402': description: Payment Required x-featured: false /x402/instant-agent-wallet: post: tags: - Execution summary: Instant Agent Wallet description: Create a session-scoped ephemeral EVM wallet for AI agent operations. Returns address and encrypted key material with USDC funding instructions. Designed for single-session autonomous use. x-price-usd: 1 operationId: instantAgentWallet requestBody: content: application/json: schema: type: object properties: chain: type: string default: base responses: '200': description: Wallet created with address '402': description: Payment Required x-featured: true /x402/agent-create-wallet: post: tags: - Execution summary: Agent Wallet Provisioning (CDP) description: Create a persistent Coinbase Developer Platform (CDP) managed wallet for AI agents on Base mainnet. Returns wallet address and API credentials for long-running autonomous deployments. x-price-usd: 2 operationId: agentCreateWallet requestBody: required: true content: application/json: schema: type: object required: - agent_id properties: agent_id: type: string description: Unique agent identifier purpose: type: string enum: - ephemeral - persistent default: persistent chain: type: string enum: - base-mainnet - ethereum-mainnet - polygon-mainnet - arbitrum-mainnet default: base-mainnet labels: type: array items: type: string tags: type: array items: type: string metadata: type: object additionalProperties: true responses: '200': description: CDP wallet created '402': description: Payment Required x-featured: false /x402/seamless-chain-bridge: post: tags: - Execution summary: Seamless Chain Bridge description: Cross-chain bridge calldata via Across Protocol for Ethereum, Base, Arbitrum, Optimism, and Polygon. Returns unsigned bridge transaction with fee breakdown, estimated settlement time, and minimum received. x-price-usd: 2 operationId: seamlessChainBridge requestBody: required: true content: application/json: schema: type: object required: - fromChain - toChain - token - amount properties: fromChain: type: string toChain: type: string token: type: string amount: type: string responses: '200': description: Bridge transaction prepared '402': description: Payment Required x-featured: false components: securitySchemes: apiKey: type: apiKey in: header name: X-API-KEY description: Prepaid credits API key (cr_live_...). Obtain via GET /api/m2m/credits/trial (free $5) or POST /api/m2m/credits/checkout/session (paid). bearerApiKey: type: http scheme: bearer description: 'Same cr_live_ key as X-API-KEY, passed as Authorization: Bearer .' x402: type: apiKey in: header name: X-PAYMENT description: x402 protocol on-chain USDC payment. Base64url-encoded signed payment payload. See /.well-known/x402.json for facilitator details. mpp: type: http scheme: payment description: 'MPP (Machine Payments Protocol) credential. Authorization: Payment . See /.well-known/mpp.json.' externalDocs: description: Full x402 service catalog url: https://coinrailz.com/x402/catalog