x402-gated transaction receipt endpoint on Base, paying $0.02 in USDC per request.
What it does
This endpoint at lowpaymentfee.com provides a transaction receipt resource (specifically for transaction ID 55) behind an x402 paywall. It is part of a broader platform that offers a variety of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per call and settled in USDC on the Base network.
The specific endpoint `/api/v1/transactions/55/receipt` accepts POST requests and returns an `application/json` response. Payment is handled via the x402 protocol: callers must include an `X-PAYMENT` header with a valid payment proof. The maximum amount required is 20,000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base), which equals $0.02 given USDC's 6 decimals. The payment timeout is 300 seconds.
The platform advertises no API keys, no rate limits, and instant access. However, documentation beyond the landing page is essentially empty (all subpages just show a "Connect wallet" prompt), so the exact schema of request bodies and response payloads for this and other endpoints is unknown. The broader catalog of endpoints listed on the homepage (sentiment analysis, summarization, embeddings, price feeds, geocoding, etc.) all share the same $0.02 pricing but none have documented input/output schemas available from the crawl.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 55 via a micropayment-gated API
- —Demonstrating x402 protocol integration for pay-per-request services
- —Programmatic access to receipt data without API key registration
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —Agents needing on-demand receipt retrieval without subscription commitments
- —Low-volume, pay-as-you-go API consumption on Base
Not for
- —High-volume batch receipt retrieval (no documented bulk endpoints)
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/55/receipt \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no documented request/response format, no examples, and all documentation pages are empty stubs. The endpoint path is hardcoded to a single transaction ID (55), making its general utility unclear.
Warnings
- —All documentation pages (/docs, /api, /pricing, /README) return only a 'Connect wallet' prompt with no actual content.
- —No OpenAPI or schema documentation is available for request or response payloads.
- —The endpoint path is hardcoded to transaction ID 55; it is unclear whether other transaction IDs are supported or what the receipt contains.
- —The broader platform lists many endpoints (AI, finance, utils) but none have verifiable documentation — their actual functionality is unconfirmed.
Citations
- —The endpoint returns a 402 challenge requiring 20000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/transactions/55/receipt
- —All APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com