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 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 via the x402 payment protocol. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an X-PAYMENT header with a valid payment proof to each request.
The specific endpoint at `/api/v1/transactions/391` is listed as "Premium API Access" and returns `application/json`. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and is discoverable. The broader platform lists endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point.
Documentation is extremely sparse: the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The actual behavior and response format of this specific transactions endpoint is unknown beyond the MIME type.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic transaction data retrieval without subscription commitments
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto-native micropayments over traditional API key billing
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/391 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is zero documentation on request parameters, response schema, or what 'Premium API Access' at /transactions/391 actually returns. No OpenAPI spec, no examples, and all doc pages render only 'Connect wallet'.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided; actual endpoint behavior is unknown
- —The purpose of /api/v1/transactions/391 ('Premium API Access') is completely opaque — no description of what data it returns
- —Cannot verify whether the broader catalog endpoints (AI, finance, utils) are functional or placeholders
Citations
- —Platform lists endpoints across data, AI, finance, and utility categories all priced at $0.02/requesthttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —x402 challenge shows maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/391
- —Docs, API, pricing, and README pages render only 'Connect wallet'https://lowpaymentfee.com/docs