Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint at `/api/v1/transactions/310` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader platform offers endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are uniformly priced at $0.02 per request.
This particular endpoint (`/api/v1/transactions/310`) is labeled "Premium API Access" but its actual functionality is not documented beyond that label. The crawled docs, pricing, API, and README pages all returned only a "Connect wallet" prompt with no additional documentation or schema details. Without further documentation, the exact input/output behavior of this endpoint remains unclear.
Capabilities
Use cases
- —Accessing premium data or transaction information via a single USDC micropayment
- —Integrating pay-per-use API calls into agent workflows without managing API keys
- —Programmatic access to platform services settled on Base L2
Fit
Best for
- —Developers wanting keyless, pay-per-call API access
- —AI agents that can settle x402 payments in USDC on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/310 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality behind "Premium API Access" is entirely opaque. The docs, pricing, API, and README pages all render only a wallet-connect prompt with no useful content.
Warnings
- —The exact functionality of /api/v1/transactions/310 is undocumented — 'Premium API Access' is the only description available.
- —All documentation pages (docs, pricing, API, README) returned only a 'Connect wallet' prompt with no technical content.
- —No OpenAPI spec, request schema, or response schema is available.
- —The platform lists many endpoints on its landing page but none have documented input/output contracts.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base network.https://lowpaymentfee.com/api/v1/transactions/310
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access.https://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base network.https://lowpaymentfee.com/api/v1/transactions/310