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 collection 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 at `/api/v1/messages/170` is listed as "Premium API Access." Its x402 challenge advertises a maximum amount of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and returns `application/json`. 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, detailed documentation, or example request/response payloads were found during the crawl; the /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no substantive content. The exact functionality of the `/api/v1/messages/170` endpoint is unclear from available materials.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification) without managing API keys
- —Fetching real-time crypto quotes, gas estimates, or exchange rates with per-call payment
- —Running geocoding or data validation as a utility service from an autonomous agent
- —Exporting data or generating analytics reports with zero upfront commitment
Fit
Best for
- —AI agents needing keyless, pay-as-you-go access to diverse API endpoints
- —Developers prototyping with low-cost, no-commitment API calls
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where per-call crypto settlement adds latency overhead
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/170 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no documentation, no example requests or responses, and the actual functionality of the /messages/170 endpoint is undefined. The broader site lists many endpoints but provides no detail on inputs, outputs, or behavior.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The exact purpose and expected input/output of /api/v1/messages/170 is unknown — 'Premium API Access' is a generic label
- —All documentation pages (/api, /pricing, /README) returned only a 'Connect wallet' prompt with no content
- —The breadth of advertised capabilities (AI, finance, geo, etc.) cannot be verified from available materials
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/messages/170
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/messages/170
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com