Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/keys/24` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 protocol — no API keys, accounts, or subscriptions are required; callers simply attach an X-PAYMENT header with a valid payment proof.
The wider platform advertises four endpoint categories: 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 the same $0.02/request price point. The platform claims no rate limits and instant access.
Important caveat: the specific endpoint `/api/v1/keys/24` is labeled generically as "Premium API Access" and does not appear in the public endpoint catalog on the landing page. There is no documentation, OpenAPI schema, or example request/response available for this or any other endpoint. The actual functionality behind this particular path is unclear — it may be an API key provisioning endpoint or a generic access point. Without schemas or docs, callers should treat this as experimental.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API key management
- —Pay-as-you-go access to data, AI, finance, or utility endpoints
Fit
Best for
- —Agents or developers who want zero-signup, pay-per-call API access
- —x402-compatible clients on the Base network
- —Low-volume or sporadic API usage where subscriptions are wasteful
Not for
- —Users needing detailed API documentation or OpenAPI schemas before integration
- —High-volume production workloads requiring SLAs or guaranteed uptime
- —Users who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/24 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (returns a valid x402 402 challenge) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation, no example requests or responses, and the specific endpoint path '/api/v1/keys/24' is not listed in the public catalog. The actual functionality is unknown.
Warnings
- —No OpenAPI schema or endpoint documentation available
- —The path /api/v1/keys/24 does not appear in the provider's public endpoint catalog — its actual functionality is unclear
- —No example request or response bodies are available; callers must experiment
- —The /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/keys/24
- —All listed endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/keys/24