x402-gated transaction receipt endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a transaction receipt (resource ID 311) behind an x402 paywall. The site advertises itself as a platform hosting multiple API categories — data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request with no API keys, no rate limits, and settlement on the Base network using USDC.
The specific endpoint `/api/v1/transactions/311/receipt` returns a JSON response upon payment. The x402 challenge confirms it is live, accepting exact-scheme payments on Base with a max amount of 20,000 base units of USDC (0x8335…), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The endpoint accepts POST requests and is marked as discoverable.
Documentation is extremely thin — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema beyond the x402 challenge's outputSchema stub, and no explanation of what the "receipt" payload actually contains. The broader site lists many endpoints across diverse categories, but none have documented schemas or example responses. Treat this as an early-stage or demonstration platform with limited transparency into actual functionality.
Capabilities
Use cases
- —Retrieving a transaction receipt for resource 311 via a single micropayment
- —Demonstrating x402 payment-gated API access on Base
- —Agent-initiated per-call data retrieval without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocols
- —Agents that need keyless, pay-per-call API access on Base
- —Testing USDC micropayment flows
Not for
- —Production workloads requiring documented request/response schemas
- —Bulk or high-volume data retrieval where per-call pricing is inefficient
- —Users who need detailed API documentation before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/311/receipt \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no documented request body or response schema, and all documentation pages are empty beyond a wallet-connect prompt. The actual content of the receipt is unknown.
Warnings
- —No OpenAPI or schema documentation available — response payload is entirely unknown
- —All doc/pricing/README pages render only 'Connect wallet' with no content
- —The specific resource '/transactions/311/receipt' is not listed on the site's homepage; its purpose is unclear
- —Platform appears early-stage or demonstrative; reliability and data quality are unverified
Citations
- —The x402 challenge requires 20,000 base units of USDC on Base (=$0.02) with a 300-second timeouthttps://lowpaymentfee.com/api/v1/transactions/311/receipt
- —The site advertises all endpoints at $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/311/receipt
- —Documentation pages (/docs, /api, /pricing, /README) contain only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs