x402-gated premium API access on Base, pay-per-call with USDC at $0.02/request.
What it does
lowpaymentfee.com hosts a collection of x402-protocol pay-per-request API endpoints on the Base network, settled in USDC. The specific endpoint at `/api/v1/policies/7` is listed as "Premium API Access" and returns a 402 challenge requiring an exact payment of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request. No API keys, subscriptions, or rate limits are advertised — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 listed at the same $0.02/request price point. However, the specific functionality behind `/api/v1/policies/7` ("Premium API Access") is not documented beyond its title, so its exact input/output behavior is unknown.
The endpoint is live and responds with a well-formed x402 version 1 challenge. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 on Base mainnet. The output schema indicates it accepts HTTP POST requests and is discoverable. Documentation pages (/docs, /pricing, /api, /README) all returned only a "Connect wallet" prompt with no substantive content, so detailed request/response schemas are unavailable.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access without subscription commitments or API key management
Fit
Best for
- —Developers wanting zero-commitment pay-per-call API access
- —AI agents with x402-compatible wallets on Base
- —Users who prefer crypto micropayments over traditional API billing
Not for
- —Users needing detailed API documentation or well-defined schemas before integrating
- —High-volume use cases where per-request pricing may add up versus flat-rate plans
- —Users without a Base-compatible USDC wallet
Quick start
# 1. Send a POST to get the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/policies/7
# 2. Parse the 402 response, construct an x402 payment proof for 20000 base units USDC on Base
# 3. Resend with the payment header:
curl -X POST https://lowpaymentfee.com/api/v1/policies/7 \
-H "X-PAYMENT: <your-x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no request/response schema, and the purpose of 'Premium API Access' at /api/v1/policies/7 is entirely opaque. All doc pages returned only 'Connect wallet' with no content. This is effectively a stub listing.
Warnings
- —The specific functionality of /api/v1/policies/7 ('Premium API Access') is undocumented — its inputs and outputs are unknown.
- —All documentation pages (/docs, /pricing, /api, /README) returned no substantive content, only a 'Connect wallet' prompt.
- —No OpenAPI spec, request schema, or response schema is available for this endpoint.
- —The endpoint name 'Premium API Access' is generic and does not describe what the endpoint actually does.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/policies/7
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/policies/7
- —All endpoints are priced at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com