x402-gated premium API access on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The site hosts a broad catalog of pay-per-call APIs spanning data & analytics, 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 at $0.02 per request, settled in USDC on Base with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/charges/263` is labeled "Premium API Access" in the x402 challenge. The challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02 per call. Payment is made via the x402 exact scheme by including an X-PAYMENT header with each POST request. The endpoint returns application/json responses.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the endpoint actually returns. The endpoint is confirmed live (402 challenge captured), but without knowing what data or functionality "Premium API Access" specifically provides beyond the generic label, this listing carries significant uncertainty.
Capabilities
Use cases
- —Accessing premium data or services with per-call USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to analytics, AI, finance, or utility endpoints
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle x402 payments autonomously
- —Users comfortable paying in USDC on the Base L2 network
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring fiat-only payment rails
- —High-volume use cases where per-request pricing may not be cost-effective compared to subscription plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/263 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and pricing is clear ($0.02 USDC per call). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the specific functionality behind 'Premium API Access' at /api/v1/charges/263 is undefined. This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition found
- —The specific functionality of /api/v1/charges/263 ('Premium API Access') is not described anywhere
- —No request or response examples available
- —The endpoint path '/api/v1/charges/263' does not match any of the documented API categories on the homepage
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/263
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The site offers APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Docs, pricing, API, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs