Pay-per-call API platform on Base network via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, paid in USDC on the Base network. The x402 protocol means there are no API keys, no sign-ups, and no rate limits — callers simply attach an X-PAYMENT header with a valid payment proof to each request.
The specific endpoint at `/api/v1/payments/77` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. The payment is settled to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation beyond the landing page is extremely thin: the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled content.
Capabilities
Use cases
- —Accessing paid API endpoints without sign-up or API key management
- —Making one-off API calls with per-request USDC micropayments on Base
- —Agent-driven workflows that need frictionless, key-less API access
Fit
Best for
- —Developers or agents wanting zero-friction, pay-as-you-go API access
- —Use cases where avoiding API key provisioning is valuable
- —Small-volume or sporadic API consumers who don't want subscriptions
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/77 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page, and no examples. The purpose of this specific '/payments/77' endpoint is unclear beyond the generic 'Premium API Access' label. Most doc pages render only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no usable content
- —The specific purpose of /api/v1/payments/77 ('Premium API Access') is not explained anywhere
- —Cannot verify what data or functionality this endpoint actually returns
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge requests maxAmountRequired of 20000 base units of USDC (0.02 USD) on Base networkhttps://lowpaymentfee.com/api/v1/payments/77
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/77