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 via the x402 payment protocol. The specific path `/api/v1/transactions/333/receipt` returns a receipt for transaction ID 333 in JSON format, gated behind a per-call USDC micropayment on the Base network. The x402 challenge confirms the endpoint is live, accepting POST requests, and settling payments to a specified Ethereum address using USDC (contract 0x8335…2913 on Base).
The broader lowpaymentfee.com platform advertises a suite of x402-gated APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 data (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments required. Payment is handled entirely through the x402 protocol on the Base L2 network.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what data the transaction receipt actually contains. The endpoint's purpose and response format must be inferred entirely from the URL path and the x402 challenge metadata.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 333 via a single micropayment
- —Demonstrating x402 protocol integration for agent-driven API consumption
- —Programmatic access to receipt data without traditional API key management
Fit
Best for
- —Developers experimenting with x402 pay-per-call protocols
- —Agents that need to fetch transaction receipts without pre-registration
- —Projects exploring micropayment-gated API patterns on Base
Not for
- —Production use cases requiring documented response schemas and SLAs
- —Bulk retrieval of many different transaction receipts (only transaction 333 is confirmed available)
- —Users who need traditional API key authentication or OAuth flows
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/333/receipt
# Returns 402 with x402 challenge; attach X-PAYMENT header with signed USDC payment to access the receipt.Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, but documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and the specific resource (transaction 333 receipt) is narrow and unexplained. The platform lists many endpoints but provides no technical detail for any of them.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only 'Connect wallet' with no usable content
- —No OpenAPI or schema available — response format for the receipt is completely unknown
- —The endpoint is for a specific transaction ID (333); it is unclear whether other transaction IDs are supported
- —No information on what data the receipt contains or what inputs the POST body expects
- —Platform lists many API categories (AI, finance, analytics, etc.) but none have documented schemas or examples
Citations
- —The endpoint returns HTTP 402 with an x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/transactions/333/receipt
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02https://lowpaymentfee.com/api/v1/transactions/333/receipt
- —All endpoints are listed at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Documentation, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs