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 51) behind an x402 paywall. It is part of a broader platform that offers a variety of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 data, and utility services — all priced at $0.02 per request, settled in USDC on the Base network.
The specific endpoint `/api/v1/transactions/51/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 "Connect wallet"), so the exact schema of request bodies and response payloads for this and other endpoints is unknown. The broader catalog lists endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, and more — all at the same $0.02 price point — but no detailed documentation or examples are available for any of them.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 51 via a micropayment
- —Demonstrating x402 protocol integration for pay-per-call APIs
- —Programmatic access to paid receipt data without API keys
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need to fetch transaction receipts on-demand
- —Use cases requiring keyless, pay-per-call API access on Base
Not for
- —Production workloads requiring well-documented API schemas and SLAs
- —Bulk retrieval of many different transaction receipts (endpoint is hardcoded to ID 51)
- —Users who need fiat-only payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/51/receipt \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing. However, there is no documentation, no OpenAPI schema, no request/response examples, and the endpoint path is hardcoded to a single transaction ID. All doc subpages are empty ('Connect wallet' only). The platform's broader catalog is listed but entirely undocumented.
Warnings
- —No documentation available — all doc/pricing/API pages return only 'Connect wallet'
- —No OpenAPI or request/response schema provided for any endpoint
- —Endpoint path is hardcoded to transaction ID 51; unclear if other IDs are supported
- —The broader platform lists many endpoints (AI, finance, utils) but none have documentation or verifiable functionality
- —Purpose and content of the 'receipt' response is unknown
Citations
- —The endpoint returns a 402 challenge requiring 20,000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/transactions/51/receipt
- —All APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The platform lists endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com