Transaction receipt endpoint on Base, paid per-call via x402 with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a transaction receipt (resource ID 191) 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 endpoints are priced at $0.02 per request, settled in USDC on the Base network with no API keys, no rate limits, and no commitments required.
The specific endpoint probed — /api/v1/transactions/191/receipt — returned a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 "exact" scheme to the specified payTo address. The endpoint accepts POST requests and returns application/json. Documentation beyond the landing page is extremely sparse: the /docs, /api, /pricing, and /README pages all rendered only a "Connect wallet" prompt with no additional technical detail.
Because there is no OpenAPI schema, no request/response examples, and no documentation describing what the receipt object actually contains or what input parameters are expected, the practical utility of this specific endpoint is unclear without experimentation. The platform concept — low-fee, pay-per-call APIs via x402 on Base — is straightforward, but the lack of documentation limits confidence in what each endpoint actually delivers.
Capabilities
Use cases
- —Retrieving a transaction receipt for a specific transaction ID via micropayment
- —Demonstrating x402 payment protocol integration for per-call API access
- —Programmatic access to paid data endpoints without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —Agents needing pay-per-call access without subscription or API key setup
- —Low-volume, on-demand data retrieval at $0.02 per request
Not for
- —High-volume batch processing where per-call fees add up quickly
- —Users who need detailed API documentation and request/response schemas before integrating
- —Non-crypto users without access to USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/191/receipt
# Returns 402 with x402 challenge; include X-PAYMENT header with valid payment proof to access the receipt.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming the payment mechanism works. However, there is no OpenAPI schema, no documentation of request parameters or response format, and the crawled docs/pricing/README pages are all empty beyond a wallet connect prompt. The specific purpose of this 'transaction receipt' endpoint is not explained anywhere.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all render only 'Connect wallet' with no content.
- —No OpenAPI or JSON schema describing request parameters or response structure for this endpoint.
- —The purpose and contents of the 'transaction receipt' for ID 191 are undocumented; unclear what data is returned.
- —The broader platform lists many endpoints (AI, finance, utils) but none could be verified beyond the landing page descriptions.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/191/receipt
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/191/receipt