x402-gated transaction receipt endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a specific transaction receipt (transaction ID 171) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of pay-per-request APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 data (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/171/receipt) returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this equates to $0.02 per call — consistent with the site's advertised pricing. Payment is made via the x402 "exact" scheme, requiring no API keys, no rate limits, and no upfront commitments. The endpoint accepts POST requests and returns application/json.
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's landing page lists many endpoints across multiple categories, but without documentation it is impossible to verify what data each endpoint actually returns or whether all listed endpoints are functional.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 171 via a single paid API call
- —Programmatic access to paid data endpoints without API key management
- —Agent-driven micropayment workflows using x402 on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol integration
- —Agents that need keyless, pay-per-call API access on Base
- —Use cases requiring low-friction micropayments in USDC
Not for
- —Users needing detailed API documentation or response schema guarantees
- —High-volume batch processing where per-call pricing may add up
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/171/receipt
# Returns 402 with x402 challenge; include X-PAYMENT header with signed USDC payment to proceed.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation beyond a landing page listing, no request/response examples, and no explanation of what the receipt payload contains. Effectively a stub with a working paywall.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README all return only a wallet-connect prompt
- —No OpenAPI or schema definition for request or response payloads
- —Unable to verify what data the transaction receipt actually contains
- —The platform lists many endpoints but none have documented schemas or examples
- —This is a single transaction-specific receipt endpoint (transaction 171); unclear if it generalizes
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/171/receipt
- —Platform advertises endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com