x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-protocol API marketplace that gates access to a variety of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint at `/api/v1/cards/65` is listed as "Premium API Access" and costs $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 exact scheme — no API keys, no rate limits, and no upfront commitments are required.
The broader platform advertises four categories of endpoints: 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 listed endpoints share the same $0.02/request pricing. The endpoint accepts HTTP POST requests and returns application/json responses.
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 usage examples available from the crawled material. The specific functionality behind `/api/v1/cards/65` is unclear beyond its generic "Premium API Access" label, making it difficult to determine what data or service it actually returns.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand, pay-as-you-go API calls settled in crypto
- —Exploring x402 protocol integration for micropayment-gated services
Fit
Best for
- —Developers wanting zero-friction, keyless API access via crypto micropayments
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer pay-per-call pricing over subscription models
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Anyone without a Base-compatible wallet or USDC holdings
- —High-volume consumers who would benefit from bulk/subscription pricing
Quick start
# The endpoint requires an x402 payment header (USDC on Base, $0.02/call)
curl -X POST https://lowpaymentfee.com/api/v1/cards/65 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the actual functionality of /api/v1/cards/65 is entirely opaque. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — the docs, API, pricing, and README pages all show only 'Connect wallet' with no technical content.
- —The specific purpose of /api/v1/cards/65 ('Premium API Access') is undefined — it is unclear what data or service this endpoint provides.
- —No request body schema or response schema is documented anywhere in the crawled material.
- —The platform lists many endpoint categories (AI, finance, data, infrastructure) but provides no evidence these endpoints actually function or what they return.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, exact scheme, on Base network, with maxAmountRequired of 20000 in USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913).https://lowpaymentfee.com/api/v1/cards/65
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only a 'Connect wallet' prompt with no further content.https://lowpaymentfee.com/docs