Transaction receipt endpoint on Base, paid per-call via x402 with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a transaction receipt (transaction ID 330) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation) — all priced at $0.02 per request with no API keys, no rate limits, and settlement on the Base network using USDC.
The specific probed endpoint (`/api/v1/transactions/330/receipt`) returns a valid x402 challenge requesting up to 20,000 base units of USDC (0x8335…) on Base. Since USDC uses 6 decimals, this translates to $0.02 per call, consistent with the site's advertised pricing. Payment is sent 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 appears to be a demonstration or early-stage x402 API marketplace. Agents should be aware that the actual response schema for this receipt endpoint is unknown.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 330 via a single paid API call
- —Demonstrating x402 protocol payment flows on Base with USDC
- —Integrating pay-per-use API access without API key management
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —Agents needing keyless, pay-per-call API access on Base
- —Testing USDC micropayment flows for API monetization
Not for
- —Production workloads requiring documented request/response schemas
- —Bulk transaction receipt retrieval (single transaction ID hardcoded in path)
- —Users who need fiat-only payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/330/receipt \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"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 specific endpoint appears to serve a single hardcoded transaction receipt with unknown payload structure.
Warnings
- —No OpenAPI or schema documentation available — response format is entirely unknown
- —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
- —The endpoint path contains a hardcoded transaction ID (330); unclear if other IDs are supported
- —Platform appears to be early-stage or a demonstration; reliability and longevity are uncertain
- —No information on what fields the receipt response actually contains
Citations
- —The site advertises all APIs at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/330/receipt
- —The platform lists APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com