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 66) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of pay-per-request APIs spanning data & analytics, AI/ML (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, with no API keys, no rate limits, and no minimum commitments.
The specific endpoint probed (/api/v1/transactions/66/receipt) returned a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per call, consistent with the site's advertised pricing. The payment scheme is "exact" with a 300-second timeout, payable to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3. The endpoint accepts POST requests and returns application/json.
Documentation is extremely thin — the /docs, /pricing, /api, 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 appears functional (live 402 challenge, 200 on root), but the lack of documentation makes it difficult to know what data is returned or what input parameters are expected.
Capabilities
Use cases
- —Retrieving transaction receipt data via a single micropayment
- —Agent-driven pay-per-call access to financial or utility APIs
- —Programmatic access to receipts without API key management
Fit
Best for
- —AI agents that can settle x402 payments in USDC on Base
- —Developers wanting zero-signup, pay-per-use API access
- —Micropayment-based workflows where $0.02/call is acceptable
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume batch processing where per-call costs add up quickly
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/66/receipt
# Returns 402 with x402 challenge; include X-PAYMENT header with signed USDC payment on Base to access.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 schema, and no examples of the actual receipt payload. The specific endpoint path (/transactions/66/receipt) suggests a fixed resource rather than a general-purpose API, adding ambiguity about its utility.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition found for any endpoint
- —The endpoint path includes a hardcoded resource ID (66), which may indicate a demo or single-resource endpoint rather than a parameterized API
- —No request body schema or response schema is documented; callers cannot know what to send or what they will receive
- —The broader platform advertises many API categories (AI, analytics, finance, utilities) but none have documented schemas
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/66/receipt