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 (transaction ID 175) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation) — all priced at $0.02 per request with no API keys, no rate limits, and settlement on the Base network using USDC.
The specific endpoint probed (`/api/v1/transactions/175/receipt`) returns a valid x402 challenge requesting up to 20,000 base units of USDC (0x8335…) on Base. Since USDC uses 6 decimals, this translates to $0.02 per call, consistent with the site's advertised flat pricing. Payment is made via the x402 "exact" scheme, with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the receipt payload actually contains. The endpoint is live and responding with a proper 402 challenge, but without documentation it is difficult to know what fields the receipt includes or what input body (if any) the POST expects.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 175 via a single paid API call
- —Demonstrating x402 pay-per-request protocol integration on Base
- —Programmatic access to receipt data without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing pay-per-call receipt retrieval on Base
- —Projects that want keyless, usage-based API access
Not for
- —Production workloads requiring documented request/response schemas
- —Bulk or high-volume receipt retrieval (no batch endpoint documented)
- —Users who need fiat-only payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/175/receipt \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is zero documentation on request format, response schema, or what the receipt contains. All doc pages render only a wallet-connect prompt. The specific endpoint path (/transactions/175/receipt) is not listed on the homepage, making its purpose unclear beyond the generic 'Premium API Access' label.
Warnings
- —No OpenAPI spec or schema documentation available
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content
- —The specific endpoint /api/v1/transactions/175/receipt is not listed among the site's advertised APIs — its purpose and response format are unknown
- —Request body schema for the POST is undocumented
Citations
- —The site advertises all APIs at $0.02 per request with no API keys, no rate limits, on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with a 300-second timeouthttps://lowpaymentfee.com/api/v1/transactions/175/receipt
- —The platform lists APIs across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com