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 (specifically for transaction ID 12) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of pay-per-request APIs spanning data & analytics, AI & machine learning (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/12/receipt` — returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02. Payment is made via the x402 "exact" scheme with a 300-second timeout. The endpoint accepts POST requests and returns application/json. No API keys or rate limits are advertised; access is granted purely through on-chain micropayment.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the receipt payload actually contains. The platform appears to be a demonstration or early-stage deployment of x402-powered APIs rather than a mature production service.
Capabilities
Use cases
- —Retrieving transaction receipt data via a single micropayment
- —Demonstrating x402 protocol integration for pay-per-request APIs
- —Programmatic access to receipt information without API key management
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —Agents that can settle USDC payments on Base
- —Use cases requiring keyless, per-call API access
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need non-crypto payment options
- —Bulk data retrieval where per-call pricing is inefficient
Quick start
# 1. Send POST to the endpoint — you'll get a 402 with payment challenge
curl -X POST https://lowpaymentfee.com/api/v1/transactions/12/receipt
# 2. Parse the 402 JSON for payment details, sign & pay via x402 client
# 3. Re-send POST with X-PAYMENT header containing the signed payment proofEndpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The docs pages are empty stubs. The specific endpoint path (/transactions/12/receipt) suggests a hardcoded resource rather than a parameterized API. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all docs pages render only 'Connect wallet'
- —The endpoint path references a specific transaction ID (12); it is unclear whether this is parameterized or a fixed demo resource
- —No response schema or example payloads are documented anywhere
- —The platform may be a demo/proof-of-concept rather than a production service
- —No information on what data the receipt actually contains
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base ($0.02)https://lowpaymentfee.com/api/v1/transactions/12/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 contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 with 6 decimalshttps://lowpaymentfee.com/api/v1/transactions/12/receipt