Pay-per-call transaction receipt endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This x402-enabled endpoint at lowpaymentfee.com provides access to a transaction receipt resource (transaction ID 221) via a POST request. Payment is settled on the Base network using USDC (contract 0x8335…2913) through the x402 exact payment scheme. The endpoint returns JSON and requires no API keys or authentication beyond the x402 payment header.
The broader lowpaymentfee.com platform advertises a suite of pay-per-call APIs spanning data & analytics (metrics, reports, data export, insights), AI & machine learning (sentiment analysis, text summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at a uniform $0.02 per request with no rate limits, no minimums, and no API key requirements.
The specific endpoint probed (/api/v1/transactions/221/receipt) returns a valid 402 challenge with maxAmountRequired of 20000 base units of USDC (6 decimals), which equals $0.02. The x402 version is 1, the payment timeout is 300 seconds, and the payTo address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3. Documentation pages on the site are sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content.
Capabilities
Use cases
- —Retrieving transaction receipts programmatically with per-call USDC payment
- —Agent-driven workflows that need on-chain payment verification without API key management
- —Demonstrating x402 protocol integration for pay-per-call services
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-as-you-go API access on Base
- —Low-volume consumers who want no subscription commitments
Not for
- —High-volume batch processing where per-call fees add up quickly
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/221/receipt \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond a landing page listing, no example request/response payloads, and the specific purpose of this particular receipt endpoint is unclear. The docs/pricing/API pages are all empty stubs.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) are effectively empty — only showing 'Connect wallet'
- —No OpenAPI or schema documentation available for any endpoint
- —The specific resource '/api/v1/transactions/221/receipt' appears to be a single hardcoded transaction ID — unclear if this generalizes to other transaction IDs
- —No example request or response bodies are available anywhere in the crawled content
- —The broader platform lists many endpoints but none have been verified beyond this single one
Citations
- —Endpoint returns 402 with x402 challenge, maxAmountRequired 20000 USDC base units on Base networkhttps://lowpaymentfee.com/api/v1/transactions/221/receipt
- —Platform lists APIs across data/analytics, AI/ML, finance/Web3, and infrastructure categories all at $0.02/requesthttps://lowpaymentfee.com
- —No API keys, no rate limits, no minimums advertisedhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/221/receipt