x402-gated API suite on Base: analytics, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com hosts a collection of pay-per-call API endpoints gated by the x402 protocol on the Base network. The specific endpoint at `/api/v1/charges/318` is labeled "Premium API Access" and accepts payment in USDC (contract 0x8335…2913 on Base) via the x402 exact-payment scheme. The maximum amount required is 20,000 base units of USDC (6 decimals), which equals $0.02 per request. No API keys, subscriptions, or rate limits are advertised — callers simply attach an X-PAYMENT header with a valid 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 listed endpoints share the same $0.02/request pricing. However, the specific endpoint `/api/v1/charges/318` does not clearly map to any single named service — it may be a generic charge endpoint or a catch-all premium access route.
Documentation is extremely thin. The /docs, /api, /pricing, 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 endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is difficult to know what data or functionality it actually returns upon successful payment.
Capabilities
Use cases
- —Paying per-call for API access without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Exploring x402 protocol integration for pay-as-you-go microservices
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-per-request API access on Base
- —Low-volume consumers who prefer no subscription commitments
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —High-volume production workloads requiring well-documented, stable schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/318 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI spec, no request/response schema, and all documentation pages are empty beyond a wallet-connect prompt. The actual functionality behind this specific endpoint path is unclear, making this effectively a stub listing.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or schema definition found; request and response formats are unknown.
- —The endpoint path /api/v1/charges/318 does not clearly correspond to any of the named services listed on the homepage.
- —Cannot verify what data or functionality is returned upon successful payment.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/318
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/318
- —All listed endpoints are priced at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com