x402-gated transaction receipt endpoint on Base, paying $0.02 in USDC per request.
What it does
This endpoint at lowpaymentfee.com provides a transaction receipt resource (transaction ID 84) behind an x402 paywall. It is part of a broader platform that offers a variety of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per call, settled in USDC on the Base network.
The specific endpoint `/api/v1/transactions/84/receipt` accepts POST requests and returns JSON. Payment is handled via the x402 protocol: callers receive a 402 challenge containing the payment details (asset, amount, payTo address), construct a signed USDC payment, and include it in the `X-PAYMENT` header on retry. The max amount required is 20,000 base units of USDC (6 decimals), which equals $0.02. The payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout.
The platform advertises no API keys, no rate limits, and instant access. However, documentation pages (`/docs`, `/pricing`, `/api`, `/README`) all returned only a "Connect wallet" prompt with no substantive content, so the actual response schema, request parameters, and detailed behavior of this endpoint are unknown. The broader site lists many endpoints across categories but provides no OpenAPI spec or detailed docs for any of them.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 84 via a single paid API call
- —Demonstrating x402 payment flow integration on Base with USDC
- —Programmatic access to receipt data without API key management
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —Agents that need to fetch transaction receipts on-demand
- —Use cases requiring keyless, pay-per-request API access
Not for
- —Bulk or high-volume receipt retrieval (no documented batch support)
- —Users who need detailed API documentation before integrating
- —Anyone without a Base-network USDC wallet
Quick start
# 1. Send POST to get the 402 challenge
curl -X POST https://lowpaymentfee.com/api/v1/transactions/84/receipt
# 2. Parse the 402 JSON for payment details
# 3. Sign a USDC payment on Base for 20000 base units ($0.02)
# 4. Retry with the X-PAYMENT header containing the signed paymentExample
Response
{
"error": "X-PAYMENT header is required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://lowpaymentfee.com/api/v1/transactions/84/receipt",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}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 wallet-connect prompt, no response schema for the actual paid resource, and no examples of successful responses. The endpoint's specific purpose (transaction 84 receipt) is narrow and unexplained.
Warnings
- —No documentation available — all doc pages return only 'Connect wallet' with no content
- —No OpenAPI or schema describing the successful response payload
- —The endpoint is for a specific transaction ID (84); unclear if other transaction IDs are available or how they are discovered
- —No information on what data the receipt actually contains
Citations
- —The platform lists APIs at $0.02 per request across data, AI, finance, and utility categorieshttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/84/receipt
- —Documentation pages return only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs