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 variety of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are paid per-request using USDC on the Base network, with no API keys, no rate limits, and no minimum commitments required.
The specific endpoint at `/api/v1/accounts/138` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per request, consistent with the site's advertised flat pricing. Payment is made via the x402 exact scheme, settling to the specified wallet address with a 300-second timeout.
The broader platform 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/request price point. However, documentation beyond the landing page is essentially empty (all sub-pages just show "Connect wallet"), so the actual request/response schemas for individual endpoints are unknown. Without documentation or OpenAPI specs, it is unclear what inputs each endpoint expects or what shape the responses take.
Capabilities
Use cases
- —Accessing premium API data without needing API key registration or subscriptions
- —Making one-off AI inference calls (sentiment, summarization, classification) paid in USDC
- —Fetching real-time crypto quotes, gas estimates, or exchange rates on a per-call basis
- —Geocoding or data validation with instant pay-per-use billing
- —Agent-driven workflows that need low-friction, wallet-based API access
Fit
Best for
- —Developers or agents who want zero-signup, pay-as-you-go API access
- —Crypto-native applications that can settle payments in USDC on Base
- —Low-volume or bursty workloads where per-request pricing is more economical than subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume production workloads where $0.02/request adds up significantly
- —Users without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/138 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI spec, no documentation beyond a landing page, no request/response schema, and all doc pages are empty stubs. The purpose of this specific /accounts/138 endpoint is unclear beyond the generic label 'Premium API Access'.
Warnings
- —No OpenAPI or schema documentation available — all doc/pricing/README pages return only 'Connect wallet'
- —The specific purpose and expected input/output of /api/v1/accounts/138 is undocumented
- —No example requests or responses are available from the provider
- —The platform lists many endpoints but none have documented schemas
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/accounts/138 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/accounts/138
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com