x402-gated premium API access on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The endpoint accepts POST requests and charges up to $0.02 per call in USDC (USD Coin), settled on-chain to a specified wallet address. Payment is handled via the x402 protocol's exact scheme — callers include an X-PAYMENT header with a signed payment proof, and the server verifies it before returning the response.
The broader lowpaymentfee.com platform advertises a suite of APIs 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 listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments. This specific endpoint (/api/v1/stripe/charges/8) is labeled "Premium API Access" but its exact functionality is not documented beyond that label — it may serve as a generic or demonstration endpoint.
The x402 challenge confirms the endpoint is live, returning a proper 402 response with version 1 of the x402 protocol. The asset is USDC on Base (contract 0x8335…2913) with a maxAmountRequired of 20000 base units, which equals $0.02 given USDC's 6 decimals. The payment timeout is 300 seconds.
Capabilities
Use cases
- —Agents that need to call APIs without pre-registering for API keys
- —Programmatic access to utility endpoints with on-chain micropayments
- —Demonstrating x402 protocol integration for per-request billing
Fit
Best for
- —Developers exploring x402 protocol integration
- —AI agents with USDC wallets on Base seeking keyless API access
- —Low-volume, pay-as-you-go API consumption without subscriptions
Not for
- —Users who need detailed documentation on what the endpoint actually returns
- —High-volume use cases where $0.02/request adds up significantly
- —Users without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/charges/8 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no documentation on what this specific endpoint actually does or returns — no OpenAPI schema, no example requests/responses, and the docs/pricing/README pages all render only a 'Connect wallet' prompt. The label 'Premium API Access' is generic and uninformative.
Warnings
- —No documentation available — docs, pricing, and README pages all show only 'Connect wallet' with no content
- —The specific functionality of /api/v1/stripe/charges/8 is undocumented; 'Premium API Access' is a generic label
- —No request or response schema is provided, so callers cannot know what to send or expect back
- —The endpoint path includes 'stripe/charges' which is unusual for an x402 endpoint and may indicate a test or placeholder
Citations
- —The endpoint returns a 402 challenge with x402Version 1, exact scheme, USDC on Base, maxAmountRequired 20000https://lowpaymentfee.com/api/v1/stripe/charges/8
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/stripe/charges/8
- —All endpoints listed at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com