Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The site hosts a broad catalog of pay-per-request APIs spanning data & analytics, AI/ML inference, finance & Web3 data, and infrastructure utilities — all priced at $0.02 per request, settled in USDC on the Base network. No API keys, rate limits, or upfront commitments are required; callers simply attach an x402 payment header to each request.
The specific endpoint `/api/v1/payments/336` is listed as "Premium API Access" and returns a valid 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals → $0.02) per call. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts HTTP POST and returns `application/json`.
Documentation on the site is extremely thin — the /docs, /pricing, /api, 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 this particular endpoint actually returns. The site's landing page groups its APIs into categories (analytics, AI, finance, utilities) but this endpoint's path (`/payments/336`) does not clearly map to any of those categories, making its actual functionality unclear.
Capabilities
Use cases
- —Accessing premium data or services without API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven workflows that need keyless, per-request billing
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents with x402-compatible wallets on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume use cases where per-request pricing may add up
- —Developers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/336 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The actual functionality behind '/api/v1/payments/336' is entirely opaque — the name 'Premium API Access' is generic and the path doesn't correspond to any documented category. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet' with no content
- —No OpenAPI or schema definition found for this endpoint
- —The endpoint path /api/v1/payments/336 does not match any of the documented API categories on the landing page — actual functionality is unknown
- —No request body schema or response schema is documented anywhere
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base ($0.02)https://lowpaymentfee.com/api/v1/payments/336
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/336
- —All APIs priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Site lists APIs in categories: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com