Pay-per-call API suite on Base (USDC) covering data, AI, finance, and utilities at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint `/api/v1/messages/36` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6-decimal precision. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises additional endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, no OpenAPI schema, request/response examples, or detailed documentation were found during the crawl; the /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no substantive content. Without schemas or sample payloads, it is unclear what request body this particular endpoint expects or what it returns.
Capabilities
Use cases
- —Agents that need on-demand API access without managing API keys or subscriptions
- —Programmatic access to data, AI inference, finance, or utility endpoints with crypto micropayments
- —Testing x402 payment flows on Base with low-cost endpoints
Fit
Best for
- —Developers exploring x402 protocol integrations
- —AI agents that settle per-call payments in USDC on Base
- —Projects needing keyless, pay-as-you-go API access
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Applications requiring non-crypto payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/36 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, and the landing page confirms the pricing model. However, there is no OpenAPI schema, no request/response examples, and no meaningful documentation — the /api, /pricing, and /README pages are all blank beyond a wallet-connect prompt. The purpose of this specific endpoint (/api/v1/messages/36) is entirely unclear.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /api, /pricing, and /README pages returned no useful content beyond 'Connect wallet'
- —The specific function of /api/v1/messages/36 ('Premium API Access') is undocumented — it is unclear what request body it expects or what it returns
- —The platform lists many endpoint categories but none have documented input/output schemas
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 (USD Coin) on Base with 300-second timeouthttps://lowpaymentfee.com/api/v1/messages/36
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/messages/36