Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request using USDC on the Base network at a flat rate of $0.02 per call. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/213` is listed as "Premium API Access" and its x402 challenge advertises a maxAmountRequired 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 broader platform also advertises 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 extremely sparse. The /docs, /pricing, /api, 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 example payloads available. The actual functionality behind this particular `/api/v1/transactions/213` endpoint is unclear — the description is generic ("Premium API Access") and does not specify what data or service it provides.
Capabilities
Use cases
- —Accessing paid API endpoints without creating accounts or managing API keys
- —Making one-off API calls with per-request USDC micropayments on Base
- —Integrating pay-as-you-go data or utility services into agent workflows
Fit
Best for
- —Developers who want zero-signup, pay-per-call API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-friction, small-denomination API billing
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume consumers who want bulk pricing or subscription discounts
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/213 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts payments. However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, no examples, and the endpoint's actual purpose ('Premium API Access' for /api/v1/transactions/213) is vague and unexplained.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific purpose of /api/v1/transactions/213 ('Premium API Access') is not explained anywhere
- —No request body schema or response schema documented — callers cannot know what to send or expect back
- —The broader platform lists many endpoints (AI, finance, utils) but none have documented schemas or examples
Citations
- —Flat pricing of $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 (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/213
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs