x402-gated transaction receipt endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides a transaction receipt resource (transaction ID 309) behind an x402 paywall. It is part of a broader platform that advertises multiple API categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request and settled in USDC on the Base network.
The specific endpoint `/api/v1/transactions/309/receipt` accepts POST requests and returns `application/json`. Payment is handled via the x402 protocol: callers receive a 402 challenge containing the accepted payment scheme (exact), the USDC asset contract on Base (`0x8335…`), and a maximum amount of 20,000 base units. Since USDC uses 6 decimals, this translates to $0.02 per call — consistent with the site's advertised flat pricing. No API keys or rate limits are required; access is granted immediately upon payment.
Documentation on the site 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 usage examples. The endpoint is live (402 challenge confirmed), but the actual data returned after payment is unknown from the available material.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 309 via a single micropayment
- —Demonstrating x402 protocol integration for pay-per-call APIs
- —Agent-driven programmatic access to paid receipt data without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC payments on Base
- —Use cases needing keyless, pay-per-request API access
Not for
- —Users who need detailed API documentation or response schemas before purchasing
- —Bulk retrieval of many different transaction receipts (only transaction 309 is exposed at this endpoint)
- —Users without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/309/receipt
# Returns 402 with x402 challenge; include X-PAYMENT header with signed USDC payment to access.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no documentation, no OpenAPI spec, no request/response examples, and the docs pages are empty stubs. The actual content returned after payment is completely unknown.
Warnings
- —No API documentation available — all doc pages render only 'Connect wallet' with no content
- —No OpenAPI or schema definition for request or response payloads
- —The endpoint is for a single hardcoded transaction ID (309); unclear if other transaction IDs are available
- —Actual response content after payment is unknown from available material
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/309/receipt
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/309/receipt