x402-gated premium API access on Base, paid per-call in USDC at $0.02/request.
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/ML inference (sentiment analysis, 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/97` is labeled "Premium API Access" in the x402 challenge and accepts HTTP POST requests. The challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. 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 the `/api/v1/charges/97` endpoint returns, as the site's landing page only describes the broader catalog without mapping charge IDs to specific services.
Capabilities
Use cases
- —Accessing pay-per-call API services without API key registration
- —Making micropayments in USDC on Base for on-demand data or utility endpoints
- —Integrating x402-compatible agents with low-cost API services
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents with x402 payment capability on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or schemas before integration
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/97 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no clarity on what '/api/v1/charges/97' specifically returns. The listing is effectively a stub with confirmed liveness and pricing.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all render only 'Connect wallet'
- —No OpenAPI or schema definition found for this endpoint
- —The specific functionality of /api/v1/charges/97 ('Premium API Access') is undefined — it does not map to any named service in the site catalog
- —Cannot verify what data or service is actually returned upon successful payment
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/97
- —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 & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/97