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 243) 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/243/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 translates to $0.02 per call, consistent with the site's advertised pricing. Payment is made via the x402 "exact" scheme to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3. No API keys or rate limits are advertised; access is gated purely by per-request micropayment.
Documentation is extremely thin — 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 endpoint is live and responding with a proper 402 challenge, but the lack of documentation makes it difficult to know what data is returned or what input parameters (if any) are expected in the POST body.
Capabilities
Use cases
- —Retrieving transaction receipt data for transaction 243 via a single micropayment
- —Demonstrating x402 protocol integration for pay-per-request APIs
- —Agent-driven programmatic access to paid data without API key management
Fit
Best for
- —Developers experimenting with x402 micropayment protocol
- —Agents that need keyless, pay-per-call API access on Base
- —Projects exploring USDC-settled per-request pricing models
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need bulk or subscription-based access to transaction data
- —Anyone needing receipts for transactions other than ID 243 (this is a single-resource endpoint)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/243/receipt \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"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. The endpoint path suggests a single fixed resource (transaction 243) rather than a general-purpose API. Effectively a stub listing.
Warnings
- —No OpenAPI spec or schema documentation available
- —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
- —Endpoint appears to serve a single fixed resource (transaction ID 243) — unclear if this is a demo or production endpoint
- —No response schema or example output available; impossible to verify what data is actually returned
- —The broader platform advertises many API categories (AI, finance, analytics, etc.) but none have documented schemas
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, on Base networkhttps://lowpaymentfee.com
- —Platform advertises 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/243/receipt