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 (transaction ID 339) 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 infrastructure utilities — all priced at $0.02 per request and settled in USDC on the Base network.
The specific endpoint `/api/v1/transactions/339/receipt` accepts POST requests and returns an `application/json` response. Payment is handled via the x402 protocol: callers must include an `X-PAYMENT` header containing a valid payment proof for 20,000 base-unit USDC (i.e., $0.02, since USDC uses 6 decimals). The payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base mainnet, with a maximum timeout of 300 seconds. No API keys or rate limits are advertised; access is purely pay-per-request.
Documentation on the site is extremely thin — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema beyond the x402 `outputSchema` stub, and no examples of what the receipt payload actually contains. The platform appears to be a demonstration or early-stage deployment of x402-based micropayment APIs.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 339 via a single micropayment
- —Demonstrating x402 protocol integration for pay-per-call APIs
- —Agent-driven retrieval of financial transaction data without API key management
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —Agents that need keyless, pay-per-call API access on Base
- —Prototyping micropayment-gated data retrieval
Not for
- —Production workloads requiring documented request/response schemas
- —Bulk or high-volume receipt retrieval (no batch endpoint visible)
- —Users who need fiat-only payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/339/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, confirming it is operational. However, there is no OpenAPI spec, no documented request body or response schema, and all secondary pages (docs, pricing, README) render only a wallet-connect prompt. The specific resource (transaction 339 receipt) is narrow and unexplained. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown.
- —All documentation pages (docs, pricing, README, api) render only 'Connect wallet' with no usable content.
- —The endpoint is scoped to a single transaction ID (339); it is unclear whether other transaction IDs are supported or how to discover them.
- —The broader platform lists many API categories (AI, analytics, finance, utils) but none have documented schemas or examples.
Citations
- —The endpoint returns a 402 challenge requiring 20,000 base-unit USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913).https://lowpaymentfee.com/api/v1/transactions/339/receipt
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The platform lists endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com
- —Documentation, pricing, API, and README pages render only a 'Connect wallet' prompt with no additional content.https://lowpaymentfee.com/docs