Pay-per-call transaction receipt endpoint on Base via x402 protocol, $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" transaction receipt resource via the x402 payment protocol. It is part of a broader platform offering multiple API categories including 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 no commitments required.
The specific endpoint `/api/v1/transactions/138/receipt` accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) with a maximum amount of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The x402 challenge confirms the endpoint is live and discoverable, with a 300-second payment timeout.
Documentation on the site is extremely sparse—most pages beyond the landing page only show a "Connect wallet" prompt. There is no OpenAPI spec, no detailed schema for request/response bodies, and no examples of what the receipt payload actually contains. The platform's value proposition centers on frictionless, wallet-based micropayments without traditional authentication, but the actual data returned by this specific receipt endpoint is undocumented.
Capabilities
Use cases
- —Retrieving a transaction receipt after completing a payment flow
- —Programmatic verification of transaction completion
- —Agent-driven micropayment workflows on Base network
Fit
Best for
- —Developers building x402-compatible payment agents
- —Applications needing frictionless per-call API access without API keys
- —Crypto-native workflows settling in USDC on Base
Not for
- —Users needing detailed API documentation or OpenAPI specs before integration
- —High-volume batch processing where per-call pricing is inefficient
- —Non-crypto workflows requiring traditional auth (OAuth, API keys)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/138/receipt \
-H "X-PAYMENT: <x402_payment_token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, no examples, and the actual purpose of the 'receipt' resource is unexplained. Most site pages render only a wallet-connect prompt.
Warnings
- —No OpenAPI spec or detailed documentation available
- —Response schema for the receipt endpoint is completely undocumented
- —Most site pages (docs, api, pricing, README) only show 'Connect wallet' with no content
- —The specific transaction ID (138) in the path suggests this may be a single-resource endpoint rather than a general-purpose API
Citations
- —Endpoint returns 402 with x402 challenge advertising USDC on Base network, maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/transactions/138/receipt
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/138/receipt