Pay-per-call API suite on Base (USDC) covering messaging, 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. No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/messages/10` is listed as "Premium API Access" and accepts HTTP POST. 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 decimals. The payment timeout is 300 seconds. The broader platform also exposes endpoints for 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.
Documentation is minimal: the landing page lists available endpoints with short descriptions and prices, but there is no OpenAPI spec, no request/response schema documentation, and the /api, /pricing, and /README pages all resolve to a bare "Connect wallet" prompt. Without detailed schemas or example payloads, callers will need to experiment to discover the expected request body format and response structure for each endpoint.
Capabilities
Use cases
- —Sending or retrieving messages via a pay-per-call interface without API key management
- —Integrating low-cost per-request APIs into agent workflows that settle payments on Base
- —Exploring x402 protocol mechanics with a live, inexpensive endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —AI agents that need keyless, pay-as-you-go API access
- —Low-volume callers who want no subscription or commitment
Not for
- —High-volume production workloads where $0.02/request adds up and bulk pricing is needed
- —Users who need detailed API documentation, schemas, or SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/10 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{"message": "Hello world"}'Example
Request
{
"message": "Hello world"
}Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, and the landing page confirms pricing and lists sibling endpoints. However, there is no OpenAPI spec, no request/response schema, no example payloads, and the /api, /pricing, and /README pages are empty. The purpose of the specific /messages/10 endpoint is unclear beyond the generic 'Premium API Access' label. The request body example above is inferred, not documented.
Warnings
- —No OpenAPI spec or request/response schema available for any endpoint
- —The /api, /pricing, and /README pages return only a 'Connect wallet' prompt with no documentation
- —The exact purpose and expected payload of /api/v1/messages/10 is undocumented — 'Premium API Access' is vague
- —Example request JSON is inferred and may not reflect the actual expected format
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/messages/10
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Basehttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/messages/10