Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request using USDC on the Base network, with no API keys, no rate limits, and no minimum commitments required.
The specific endpoint at `/api/v1/payments/85` 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 request (USDC uses 6 decimals). Payment is settled on-chain via the x402 "exact" scheme with a 300-second timeout.
The broader platform advertises additional endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02/request price point. However, documentation pages beyond the landing page returned only a "Connect wallet" prompt with no substantive content, so the actual capabilities and response formats of these endpoints remain unverified. The specific functionality behind the "Premium API Access" label at `/api/v1/payments/85` is not documented.
Capabilities
Use cases
- —Accessing paid API endpoints without traditional API key registration
- —Making per-request micropayments in USDC on Base for data or utility services
- —Integrating x402-compatible agents with a low-cost API gateway
Fit
Best for
- —Developers wanting frictionless pay-per-use API access without subscriptions
- —AI agents that support x402 payment protocol on Base
- —Users who prefer crypto-native micropayments over traditional billing
Not for
- —Users needing detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Users without access to USDC on the Base network
Quick start
# The endpoint requires an x402 payment header (USDC on Base).
# Using curl to see the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/payments/85 \
-H 'Content-Type: application/json'
# Returns 402 with x402 payment challenge.
# Use an x402-compatible client to attach the X-PAYMENT header automatically.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing. However, there is no OpenAPI schema, no documentation beyond the landing page, no example requests or responses, and the actual functionality behind "Premium API Access" at /api/v1/payments/85 is entirely undocumented. All doc/pricing/API pages just show "Connect wallet" with no content.
Warnings
- —The specific functionality of /api/v1/payments/85 ('Premium API Access') is not documented anywhere in the crawled material.
- —All documentation pages (/docs, /api, /pricing, /README) returned only 'Connect wallet' with no substantive content.
- —No OpenAPI schema, request/response examples, or input parameter documentation available.
- —The broader platform lists many endpoints but none have verified functionality beyond the landing page descriptions.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/85
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/85