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 226) 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 no commitments.
The specific endpoint probed (`/api/v1/transactions/226/receipt`) returns a valid x402 challenge on POST, accepting payment in USDC on the Base network. The `maxAmountRequired` is 20000 base units of USDC (6 decimals), which equals $0.02 — consistent with the site's advertised flat pricing. Payment is settled on-chain to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the exact-amount scheme with a 300-second timeout.
Documentation is extremely sparse: the /docs, /api, /pricing, 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 the x402 challenge is well-formed, but without documentation it is unclear what fields the receipt response includes or what input parameters (if any) the POST body expects.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction ID 226 via a micropayment
- —Demonstrating x402 protocol payment flows on Base with USDC
- —Integrating pay-per-call API access without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing on-demand transaction receipts without subscription
- —Projects wanting no-auth, pay-as-you-go API access on Base
Not for
- —Bulk retrieval of many transaction receipts (no documented batch endpoint)
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/226/receipt \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge is live and well-formed, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation beyond a wallet-connect prompt, no request/response schema, and no examples. The specific endpoint's purpose ('transaction receipt') is only inferable from the URL path and the generic title 'Premium API Access'. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition found for request or response payloads
- —The specific content of the receipt response is unknown; 'Premium API Access' is a generic description
- —The broader platform advertises many endpoints (AI, finance, utils) but none were individually verified beyond this one
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/226/receipt
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/226/receipt
- —The platform lists APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com