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 commitments required.
The specific endpoint `/api/v1/charges/113` is listed as "Premium API Access" and returns a standard 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 to the specified payTo address, with a 300-second timeout. The endpoint accepts HTTP POST requests and returns application/json responses.
Documentation on the site 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 data this particular endpoint returns. The endpoint is confirmed live (402 challenge captured), but without documentation it is unclear what specific functionality "Premium API Access" at `/charges/113` provides versus the other named endpoints on the platform.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without traditional API key registration
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —AI agents that can autonomously pay for API calls via crypto
- —Users who want no-signup, no-rate-limit API access
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring guaranteed SLAs or enterprise support
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/113 \
-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 on Base). However, there is no documentation, no OpenAPI spec, no request/response examples, and the specific functionality of /api/v1/charges/113 ('Premium API Access') is undefined. The docs, pricing, and README pages are all blank beyond a wallet connect prompt.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition for request or response payloads
- —The specific functionality of /api/v1/charges/113 ('Premium API Access') is unclear — it does not match any of the named endpoints listed on the homepage
- —Cannot verify what data or service this endpoint actually returns without making a paid request
Citations
- —All endpoints 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
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/charges/113