Pay-per-call transaction receipt endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" transaction receipt resource via the x402 payment protocol. It is part of a broader platform offering multiple API categories including Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure utilities—all priced at $0.02 per request with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/transactions/50/receipt` accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) with a maximum amount of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The x402 challenge confirms the endpoint is live and uses the "exact" payment scheme with a 300-second timeout.
Documentation on the site is extremely sparse—most pages beyond the landing page only show a "Connect wallet" prompt. There is no OpenAPI spec, no detailed request/response schema, and no examples of what the receipt payload actually contains. The endpoint's purpose (retrieving a receipt for transaction ID 50) can be inferred from the URL structure, but the actual response format and required request body are unknown.
Capabilities
Use cases
- —Retrieving transaction receipts programmatically with per-call USDC payment
- —Integrating pay-per-use API access without traditional API key management
- —Building agent workflows that settle API costs on-chain via x402
Fit
Best for
- —Developers wanting keyless, pay-per-call API access on Base
- —AI agents that can settle x402 payments autonomously
- —Projects needing low-cost ($0.02) on-chain settled API calls
Not for
- —Users who need detailed documentation or OpenAPI specs before integrating
- —High-volume use cases where per-call crypto settlement overhead is impractical
- —Developers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/50/receipt \
-H "X-PAYMENT: <x402_payment_token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge with clear pricing and network details. However, there is no OpenAPI spec, no documentation of request/response schemas, no examples, and the actual functionality of the receipt endpoint is only inferable from the URL path. Most site pages return only a wallet-connect prompt.
Warnings
- —No OpenAPI or schema documentation available
- —Response format and required request body are completely undocumented
- —Most documentation pages only show 'Connect wallet' with no content
- —The specific purpose of 'transaction 50 receipt' is unclear—may be a demo/placeholder endpoint
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base network at maxAmountRequired 20000 (=$0.02)https://lowpaymentfee.com/api/v1/transactions/50/receipt
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/50/receipt