Pay-per-call premium API access on Base via x402 — $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The site hosts a broad catalog of pay-per-request 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, payable in USDC on the Base network with no API keys, no rate limits, and no minimum commitments.
The specific endpoint `/api/v1/charges/343` is labeled "Premium API Access" and accepts HTTP POST requests. The x402 challenge confirms it is live, requesting up to 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 payTo address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.
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 of what this particular endpoint returns. The landing page lists many API paths but provides no detail on input parameters or response formats. Because of this, it is unclear what data or functionality the `/api/v1/charges/343` endpoint specifically provides versus the other listed endpoints.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Testing x402 payment protocol integrations
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible wallet holding USDC
- —High-volume consumers who would benefit from bulk pricing or subscriptions
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/343 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation beyond a landing page listing, no request/response schemas, and no examples. The specific purpose of /api/v1/charges/343 is ambiguous — it may be a generic charge endpoint rather than a distinct API. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all /docs, /pricing, /api, /README pages return only a wallet-connect prompt
- —The specific purpose of /api/v1/charges/343 ('Premium API Access') is unclear and may be a generic or placeholder endpoint
- —No request body schema or response schema documented anywhere
- —Cannot verify what data or functionality is actually returned after payment
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Site offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —x402 challenge confirms live 402 response with maxAmountRequired of 20000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/charges/343