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/378` is labeled "Premium API Access" and accepts POST requests. The x402 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 with a 300-second timeout. The response MIME type is application/json.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples available. It is unclear what specific data or functionality this particular charge endpoint (378) returns, as the site lists many different API categories but does not map charge IDs to specific services. The endpoint is confirmed live (402 challenge captured successfully).
Capabilities
Use cases
- —Programmatic access to paid API services without traditional API key management
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Accessing data, analytics, AI inference, or utility endpoints at micro-transaction pricing
Fit
Best for
- —Developers or agents wanting frictionless pay-per-call API access without subscriptions
- —Crypto-native applications that can settle payments in USDC on Base
- —Low-volume or sporadic API consumers who prefer no minimums or commitments
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Anyone without a Base-compatible wallet or USDC holdings
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/378 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no clarity on what this specific charge ID (378) returns. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —Docs, API, pricing, and README pages all render only 'Connect wallet' with no usable content
- —It is unclear what specific service charge ID 378 maps to among the many listed API categories
- —No examples or sample responses are provided anywhere on the site
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/378
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The site offers APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs