Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API marketplace that exposes a broad set of endpoints across four categories: Data & Analytics (metrics, reports, export, insights), 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, payable in USDC on the Base network via the x402 protocol — no API keys, no rate limits, and no upfront commitments.
The specific endpoint at `/api/v1/messages/193` is described as "Premium API Access" and returns a standard x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals). Payments are sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base, using the "exact" payment scheme with a 300-second timeout. The endpoint accepts HTTP POST and returns `application/json`.
Documentation beyond the landing page is sparse — the /api, /pricing, and /README pages all resolve to a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material. The purpose of the `/api/v1/messages/193` path specifically (as opposed to the other listed endpoints) is unclear; it does not appear in the site's own catalog of available APIs.
Capabilities
Use cases
- —Querying real-time financial data (prices, exchange rates, gas estimates) with per-call USDC micropayments
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) without API key management
- —Accessing utility services (geocoding, validation, conversion) on a pay-as-you-go basis
- —Building agent workflows that autonomously purchase API calls via x402 on Base
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access settled in USDC on Base
- —AI agents that need to autonomously purchase API calls without pre-provisioned keys
- —Prototyping and low-volume usage where $0.02/request with no minimums is cost-effective
Not for
- —High-volume production workloads where per-request crypto settlement adds latency and cost overhead
- —Users who need detailed SLAs, rate-limit guarantees, or enterprise support
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/193 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/messages/193",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-token>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page catalog, and the specific /api/v1/messages/193 path is not listed among the site's own advertised endpoints. The purpose and expected input/output of this particular endpoint are unknown.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —The endpoint path /api/v1/messages/193 does not appear in the provider's own listed API catalog; its specific function is unclear
- —All documentation pages (/api, /pricing, /README) return only a 'Connect wallet' prompt with no technical content
- —No usage examples, error codes, or rate limit information documented
Citations
- —All endpoints priced at $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/messages/193