x402-gated premium API access on Base, pay $0.02 per request in USDC with no API keys.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are gated behind the x402 payment protocol on the Base network, accepting USDC (USD Coin) at $0.02 per request. No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid payment proof to access any endpoint.
The specific endpoint at `/api/v1/charges/104` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises categories including metrics, reports, data export, insights, 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 (docs, pricing, README) returned only a "Connect wallet" prompt with no substantive content, so the actual behavior and response schemas of individual endpoints remain undocumented.
Capabilities
Use cases
- —Accessing data analytics and metrics without managing API keys or subscriptions
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with per-request USDC payments
- —Fetching financial data like token quotes, exchange rates, and gas estimates via micropayments
- —Using utility services such as geocoding, validation, and conversion on a pay-as-you-go basis
Fit
Best for
- —Developers who want instant API access without signup or API key management
- —Agents and bots that can settle payments programmatically via x402 on Base
- —Users who prefer pay-per-request pricing with no minimum commitments
Not for
- —Users who need detailed API documentation and response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Developers not set up for USDC payments on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/104 \
-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 ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation of request/response formats, and the docs/pricing/README pages are all empty stubs showing only 'Connect wallet'. The actual functionality behind 'Premium API Access' at /api/v1/charges/104 is not described, making this effectively a stub listing.
Warnings
- —No API documentation available — all doc pages return only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format for this endpoint
- —The purpose of /api/v1/charges/104 ('Premium API Access') is unclear and may be a generic or placeholder endpoint
- —Response schema and actual data returned are completely unknown
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/104
- —USDC contract address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/104
- —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 & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com