x402-gated transaction receipt endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a transaction receipt (resource ID 340) behind an x402 paywall. The site advertises itself as a platform hosting multiple API categories — 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. No API keys or rate limits are required; callers pay per request via the x402 protocol.
The specific endpoint `/api/v1/transactions/340/receipt` returns a JSON response (MIME type application/json) after a valid x402 payment. The x402 challenge confirms the endpoint is live, using the "exact" payment scheme on Base with USDC (contract 0x8335…2913). The maximum amount required is 20,000 base units of USDC (6 decimals), which equals $0.02. Payment is directed to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 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 explanation of what the transaction receipt contains or what input parameters (if any) the POST body expects. The endpoint appears functional based on the 402 challenge, but the lack of documentation makes it difficult to determine the actual utility of the returned data.
Capabilities
Use cases
- —Retrieving a transaction receipt for resource ID 340 via programmatic payment
- —Demonstrating x402 protocol integration for per-call micropayments
- —Agent-driven data retrieval with on-chain USDC settlement
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —Agents that need to purchase data per-call without API keys
- —Use cases requiring low-friction, keyless API access on Base
Not for
- —Users needing well-documented API contracts with full schemas
- —High-volume batch retrieval where per-call payment overhead is impractical
- —Anyone who needs to understand the response format before paying
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/340/receipt
# Returns 402 with x402 challenge; include X-PAYMENT header with valid USDC payment proof to receive the receipt.Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response schema, and no explanation of what the receipt contains. The docs pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition; request body format and response structure are unknown
- —The specific resource '/api/v1/transactions/340/receipt' is not listed among the site's advertised APIs — its purpose is unclear
- —Cannot verify what data the receipt contains or whether it has real utility
Citations
- —The endpoint returns a 402 challenge with x402Version 1, exact scheme, Base network, USDC asset at 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/transactions/340/receipt
- —The site advertises APIs across data & analytics, AI & ML, finance & Web3, and infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base network settlementhttps://lowpaymentfee.com