x402-gated transaction receipt endpoint on Base, payable in USDC per call.
What it does
This endpoint at lowpaymentfee.com provides access to a specific transaction receipt (transaction ID 282) behind an x402 paywall. The parent site lowpaymentfee.com advertises a broad suite of pay-per-request 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 via the x402 protocol.
The specific endpoint probed — `/api/v1/transactions/282/receipt` — returns a valid x402 challenge with `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 `exact` scheme to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`. The endpoint accepts POST requests and returns `application/json`. No API keys or rate limits are advertised; access is gated purely by x402 micropayment.
Documentation is extremely thin — 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 site's landing page lists many endpoints but provides no detail on request parameters or response formats for any of them. This endpoint appears to be part of a demonstration or showcase platform for low-fee x402 micropayments rather than a well-documented production API.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 282 via micropayment
- —Demonstrating x402 protocol payment flow on Base with USDC
- —Agent-initiated pay-per-call data retrieval without API keys
Fit
Best for
- —Developers experimenting with x402 micropayment protocol
- —Agents that need keyless, pay-per-call API access on Base
- —Testing USDC micropayment flows at $0.02 per request
Not for
- —Production use requiring documented request/response schemas
- —Bulk or high-volume data retrieval (no documented batch support)
- —Users who need traditional API key authentication or invoicing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/282/receipt
# Returns 402 with x402 challenge; attach X-PAYMENT header with USDC payment proof on Base to access the receipt.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no examples of what the receipt contains. The endpoint path suggests a single fixed resource (transaction 282) rather than a parameterized API. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all render only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —Endpoint path is hardcoded to transaction ID 282; unclear if this is parameterizable
- —The broader site lists many endpoints but none have documented schemas or examples
- —May be a demo/showcase site rather than a production API
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/282/receipt
- —All endpoints on the site are priced at $0.02 per request with no API keys, no rate limitshttps://lowpaymentfee.com
- —The site lists APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs