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 across data analytics, AI/ML inference, 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 commitments required. The specific endpoint at `/api/v1/transactions/253` is labeled "Premium API Access" and accepts x402 payments.
The platform advertises a flat $0.02 per request across its listed endpoints. The probed endpoint's x402 challenge shows a `maxAmountRequired` of 20000 in USDC (6 decimals), which equals $0.02 — consistent with the site's stated pricing. Payment is settled on-chain to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` on Base.
The broader platform lists 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. However, 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 crawled content. The specific functionality of the `/api/v1/transactions/253` endpoint beyond its "Premium API Access" label is unknown.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key registration
- —Fetching real-time crypto token quotes and gas estimates via per-request USDC payments
- —Running geocoding or data validation utilities with zero commitment
Fit
Best for
- —Developers wanting instant API access without signup or API keys
- —Agents that can settle x402 payments in USDC on Base
- —Low-volume or exploratory use cases where per-call pricing is preferred
Not for
- —High-volume production workloads where subscription pricing would be cheaper
- —Users who cannot transact in USDC on the Base network
- —Anyone needing detailed API documentation or guaranteed SLAs
Quick start
# The endpoint requires an x402 payment header (USDC on Base).
# Use an x402-compatible client to auto-negotiate payment.
curl -X POST https://lowpaymentfee.com/api/v1/transactions/253 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"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, no documentation beyond a wallet-connect prompt, and the specific purpose of the /api/v1/transactions/253 endpoint is undefined. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all docs/pricing/README pages return only 'Connect wallet'
- —The specific functionality of /api/v1/transactions/253 ('Premium API Access') is undocumented
- —No request or response examples available; input format is unknown
- —The platform lists many endpoint categories but none have documented schemas or usage guides
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 USDC (6 decimals = $0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/253
- —USDC asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/253
- —Platform lists endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com