x402-gated API suite on Base: analytics, AI, finance, and utility endpoints at $0.02/request via USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-call API endpoints gated by the x402 protocol, settling payments in USDC on the Base network. The specific endpoint at `/api/v1/stripe/charges/135` is listed as "Premium API Access" and requires a payment of up to 20,000 base units of USDC (0.02 USD) per request. No API keys or rate limits are advertised; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises four categories of endpoints: 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 are listed at the same $0.02/request price point.
Documentation 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 usage examples available from the crawl. The purpose of this specific `/api/v1/stripe/charges/135` endpoint is unclear from its path alone (it references Stripe charges), and the actual input/output behavior cannot be confirmed without making a paid request. The x402 challenge is live and well-formed, confirming the endpoint is operational.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without traditional API key registration
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Testing x402 protocol integrations with a low-cost live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —AI agents that can autonomously pay for API calls via crypto
- —Users who want no-signup, no-rate-limit API access
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Production workloads requiring well-documented request/response schemas
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/charges/135 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint is operational at $0.02 USDC per call. However, there is no OpenAPI spec, no documentation beyond a wallet-connect prompt, no request/response examples, and the specific purpose of this endpoint (stripe/charges/135) is ambiguous. Effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README all return only a 'Connect wallet' prompt
- —No OpenAPI or schema definition found; request and response formats are unknown
- —The endpoint path '/api/v1/stripe/charges/135' references Stripe charges but its actual function is undocumented
- —No examples of successful responses are available from the crawl
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/stripe/charges/135
- —All endpoints are listed at $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform advertises four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/stripe/charges/135