Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/charges/69` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader platform offers endpoints across four categories: 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 endpoints are priced uniformly at $0.02 per request.
Documentation is extremely sparse — 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 example payloads available. The endpoint is live and responds with a valid x402 challenge, but without documentation it is unclear what request body the `/api/v1/charges/69` endpoint expects or what it returns.
Capabilities
Use cases
- —Accessing premium API endpoints without traditional API key registration
- —Making one-off API calls paid in USDC on Base network
- —Agent-driven workflows that need keyless, pay-as-you-go API access
Fit
Best for
- —Developers who want zero-signup API access via crypto micropayments
- —AI agents that can autonomously pay for API calls using x402
- —Users already holding USDC on Base who want frictionless API consumption
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Teams requiring fiat-only payment methods with no crypto wallet
Quick start
# Endpoint requires an x402 payment header with USDC on Base.
# 1. Send a POST to get the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/charges/69
# 2. Attach the X-PAYMENT header (constructed per x402 spec) and resend.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response documentation, no examples, and the docs pages are empty. The purpose of this specific endpoint (/api/v1/charges/69) is unclear beyond the label 'Premium API Access'. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all docs pages render only 'Connect wallet'
- —The specific purpose and expected request body for /api/v1/charges/69 are undocumented
- —No example responses are available to verify what the endpoint actually returns
- —The platform lists many endpoint categories but none have documented schemas
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/69
- —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 in Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs