Pay-per-call API platform on Base (USDC) covering analytics, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/crypto market data, and general utility services. All endpoints are paid per-request using USDC on the Base network via the x402 protocol — no API keys, no rate limits, and no subscriptions required.
The specific endpoint at `/api/v1/payments/50` is listed as "Premium API Access" and accepts POST requests. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals). The broader platform advertises the same $0.02 flat rate across all its endpoints, which include sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, gas estimates, geocoding, validation, conversion, and data export.
Documentation is extremely sparse — 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 crawled material. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is unclear what request body the POST endpoint expects or what response payload it returns.
Capabilities
Use cases
- —Agents needing on-demand API access without managing API keys or subscriptions
- —Programmatic access to analytics, AI inference, or financial data with per-call USDC payments
- —Lightweight utility calls (geocoding, validation, conversion) paid via x402 on Base
Fit
Best for
- —Developers and agents who want zero-signup, pay-as-you-go API access
- —Use cases requiring very low per-call costs ($0.02) settled on-chain
- —Projects already operating on the Base L2 network with USDC
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume production workloads that need SLAs, support, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/50 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing. However, documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no examples. The purpose of this specific '/payments/50' endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all render only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific purpose and expected request body for /api/v1/payments/50 is undocumented
- —No response schema or example responses available
- —The broad catalog of endpoints (AI, analytics, finance, utils) is advertised but none have documented input/output contracts
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/50
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/50
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com