Pay-per-call premium API access on Base via x402 — $0.02/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/294` is listed as "Premium API Access" and returns a valid x402 challenge with 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 by including an X-PAYMENT header. The endpoint accepts HTTP POST requests and returns application/json responses. The payment timeout is 300 seconds.
Documentation beyond the landing page is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no additional technical content. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. It is unclear what specific functionality the `/api/v1/charges/294` endpoint provides beyond the generic "Premium API Access" label, as it does not map to any of the named API categories on the homepage. Prospective users should be aware that without documentation, the actual input parameters and response format are unknown.
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
- —Integrating pay-per-use endpoints into applications without subscription commitments
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents with x402-compatible payment capabilities
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume use cases where per-request pricing may be less economical than bulk plans
- —Developers without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/294 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no OpenAPI spec, no documentation, no request/response examples, and the specific function of /api/v1/charges/294 is unclear. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific endpoint /api/v1/charges/294 does not correspond to any named API on the homepage catalog — its actual functionality is unknown
- —No request or response examples available; input parameters are undocumented
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/charges/294
- —Site offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no technical contenthttps://lowpaymentfee.com/docs