Pay-per-call API access keys on Base via x402 — $0.02 per request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, rate limits, or upfront commitments required.
The specific endpoint at `/api/v1/keys/80` is labeled "Premium API Access" and carries a maximum charge of 20,000 base units of USDC (i.e., $0.02, since USDC uses 6 decimals). The x402 challenge confirms the endpoint is live, accepting POST requests and settling payments to a Base-network address via the "exact" payment scheme. The broader platform advertises additional 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 and pricing, but there is no OpenAPI spec, no detailed request/response schemas, and the /api, /pricing, and /README pages all resolve to a bare "Connect wallet" prompt. Without schema documentation it is unclear what request body `/api/v1/keys/80` expects or what its response payload looks like. The endpoint appears to be a key-provisioning or access-granting call, but the exact semantics are unconfirmed.
Capabilities
Use cases
- —Acquiring premium API access keys without traditional signup or subscription
- —Making one-off paid API calls for analytics, AI inference, or financial data
- —Integrating pay-per-request endpoints into autonomous agent workflows on Base
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments in USDC on Base
- —Projects needing low-cost micro-transactions for API calls
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who prefer flat-rate or subscription pricing
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/80 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, and no documentation beyond a landing-page listing. The purpose of the /api/v1/keys/80 endpoint is ambiguous. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request/response formats are unknown.
- —The /api, /pricing, and /README pages all return only a 'Connect wallet' prompt with no useful content.
- —The exact purpose and payload of /api/v1/keys/80 ('Premium API Access') is unclear — it may provision keys or grant access, but this is unconfirmed.
- —No examples or detailed endpoint descriptions are provided by the provider.
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —x402 challenge returns 402 with maxAmountRequired 20000 USDC (6 decimals = $0.02) on Base networkhttps://lowpaymentfee.com/api/v1/keys/80
- —Asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is USDC on Basehttps://lowpaymentfee.com
- —Platform lists endpoints for analytics, AI, finance, and infrastructure categorieshttps://lowpaymentfee.com