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 188) 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/188/receipt) returned a valid x402 challenge with a 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 with a 300-second timeout. 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 further 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 API paths but provides no detail on request parameters or response formats for any of them. This makes it difficult to assess the actual utility of the endpoint without making a paid request.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 188 via a micropayment
- —Demonstrating x402 protocol payment flows on Base
- —Agent-driven pay-per-request data retrieval without API keys
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC payments on Base automatically
- —Use cases requiring keyless, pay-as-you-go API access
Not for
- —Users needing detailed API documentation or schemas before purchasing
- —High-volume batch retrieval where per-request pricing is inefficient
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/188/receipt \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming it is operational. However, there is no OpenAPI spec, no documentation of request parameters or response schema, and the docs/pricing/README pages are all empty beyond a wallet-connect prompt. The specific endpoint appears to be for a single hardcoded transaction ID (188), and the broader platform's many advertised APIs lack any documented schemas or examples. This is effectively a stub listing.
Warnings
- —No OpenAPI spec or schema documentation available for any endpoint on the platform
- —The /docs, /pricing, /api, and /README pages contain no usable content
- —This endpoint targets a specific transaction ID (188) — unclear if it generalizes to other IDs
- —No request body schema or response schema documented; actual payload contents are unknown
- —The platform lists many API categories (AI, finance, analytics, etc.) but none have documented behavior
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/188/receipt
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/188/receipt
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform advertises APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com