x402-gated lab results endpoint on Base, pay-per-request with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a specific lab result resource (ID 21) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme. The maximum amount required per call is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals).
The provider lowpaymentfee.com hosts a broader suite of pay-per-call 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 endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments. However, this specific listing covers only the `/api/v1/lab/results/21` resource, whose exact data content is not documented — the description simply reads "Premium API Access."
Because there is no OpenAPI schema, no request/response examples, and no documentation beyond the landing page listing, the actual payload structure and the meaning of "lab results" remain unclear. The endpoint is confirmed live via a valid 402 challenge.
Capabilities
Use cases
- —Fetching a specific lab result (ID 21) via a single micropayment
- —Demonstrating x402 pay-per-request integration on Base
- —Agent-driven data retrieval without API key provisioning
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC payments on Base
- —Use cases requiring keyless, per-call API access
Not for
- —Users needing documented request/response schemas before integration
- —Bulk or high-volume data retrieval where subscription pricing is cheaper
- —Anyone who needs to understand the data semantics of "lab results" before paying
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/lab/results/21 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and no documentation explaining what "lab results/21" actually returns. The listing is essentially a stub with verified liveness.
Warnings
- —No documentation exists for the /api/v1/lab/results/21 endpoint — the meaning of 'lab results' and the expected request/response format are unknown.
- —No OpenAPI spec or schema is provided by the server.
- —The /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content.
- —This appears to be a demo or showcase site for x402 micropayments; the actual data behind the endpoint may be placeholder content.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, accepting USDC on Base network with maxAmountRequired of 20000 base units.https://lowpaymentfee.com/api/v1/lab/results/21
- —All endpoints on the site are listed at $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/lab/results/21