Transaction receipt endpoint on Base, paid per-call via x402 with USDC.
What it does
This endpoint at lowpaymentfee.com provides a transaction receipt resource at `/api/v1/transactions/251/receipt`. It is part of a broader platform that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all gated via the x402 payment protocol on the Base network using USDC.
The specific endpoint probed returns a 402 challenge requesting payment of up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call. Payment is made via the x402 "exact" scheme to the specified wallet address. The platform advertises a flat $0.02 per request across all endpoints, with no API keys, no rate limits, and no minimum commitments required.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the receipt endpoint actually returns. The endpoint path suggests it retrieves a receipt for a specific transaction (ID 251), but the exact request body format and response structure are unknown. The platform appears to be a demonstration or early-stage deployment of x402-gated APIs.
Capabilities
Use cases
- —Retrieving a transaction receipt for a specific transaction ID via micropayment
- —Demonstrating x402 protocol payment flows on Base with USDC
- —Agent-driven per-call API access without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-call API access on Base
- —Testing micropayment-gated endpoint integrations
Not for
- —Production workloads requiring documented request/response schemas
- —Bulk transaction receipt retrieval at scale (no batch endpoint documented)
- —Users who need fiat-only payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/251/receipt
# Returns 402 with x402 challenge; include X-PAYMENT header with signed USDC payment to proceed.Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no documentation, no OpenAPI spec, no request/response examples, and the docs pages are empty stubs. The purpose and output of this specific receipt endpoint are unclear beyond what can be inferred from the URL path.
Warnings
- —No OpenAPI or schema documentation available — request body and response format are entirely unknown.
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content.
- —The specific endpoint path (/api/v1/transactions/251/receipt) appears to be for a single hardcoded transaction ID; unclear if this is a general-purpose endpoint.
- —Platform appears to be early-stage or a demo deployment.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base network.https://lowpaymentfee.com/api/v1/transactions/251/receipt
- —The platform advertises $0.02 per request across all endpoints with no API keys, no rate limits, and instant access.https://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/transactions/251/receipt