x402-gated premium API access on Base, pay $0.02 per request in USDC with no API keys.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to gate access to a variety of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. The specific endpoint at `/api/v1/charges/81` is labeled "Premium API Access" and accepts POST requests, settling payments in USDC on the Base network.
The x402 challenge captured from this endpoint advertises a maximum amount of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per request. The platform advertises uniform $0.02/request pricing across all its endpoints, with no API keys, no rate limits, and no minimum commitments required — callers simply attach an X-PAYMENT header to each request.
The broader platform lists endpoints for metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation. However, this specific listing covers only the `/api/v1/charges/81` endpoint. Documentation pages (docs, pricing, README) returned minimal content (just a "Connect wallet" prompt), so the exact request/response schemas for this endpoint are unknown.
Capabilities
Use cases
- —Agents that need on-demand API access without pre-registering for API keys
- —Programmatic access to premium data or services with per-call USDC micropayments
- —Testing x402 protocol integrations on Base network
Fit
Best for
- —Developers or agents wanting zero-signup, pay-as-you-go API access
- —x402-compatible wallets and agent frameworks on Base
- —Low-volume or bursty workloads where subscription pricing is wasteful
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Callers without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/81 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no documentation of request/response formats, and the docs/pricing/README pages are empty stubs. The purpose of this specific endpoint (/api/v1/charges/81) beyond the generic label 'Premium API Access' is unclear.
Warnings
- —No request or response schema available — the exact functionality behind /api/v1/charges/81 is undocumented
- —Documentation pages (/docs, /pricing, /README) returned only 'Connect wallet' with no useful content
- —The endpoint name 'Premium API Access' is generic and does not describe what data or service is returned
- —Cannot verify what the endpoint actually returns upon successful payment
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/81
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/81