Pay-per-request premium API access on Base via x402 — $0.02/call in USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints gated by the x402 payment protocol. This specific endpoint (`/api/v1/policies/23`) is listed as "Premium API Access" and accepts POST requests. Payment is settled on the Base network using USDC (contract 0x8335…2913) with a maximum amount of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals). No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com 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 priced at $0.02 per request.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/policies/23` endpoint actually returns. The endpoint is live (returns a proper 402 x402 challenge), but without documentation it is unclear what data or functionality "Premium API Access" provides beyond the generic label.
Capabilities
Use cases
- —Accessing premium API data without signing up for an account or obtaining API keys
- —Making one-off paid API calls settled instantly on Base L2 in USDC
- —Integrating pay-per-request endpoints into autonomous agent workflows
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Developers who cannot transact in USDC on the Base network
Quick start
# 1. Send a POST to get the 402 challenge
curl -X POST https://lowpaymentfee.com/api/v1/policies/23
# Response: 402 with x402 payment challenge
# 2. Construct an X-PAYMENT header using the challenge details
# (pay 20000 base units = $0.02 USDC on Base to 0x1A2B...85F3)
# 3. Replay the POST with the payment proof header
curl -X POST https://lowpaymentfee.com/api/v1/policies/23 \
-H "X-PAYMENT: <signed-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no OpenAPI schema, no documentation, no request/response examples, and the purpose of '/api/v1/policies/23' is entirely opaque beyond the label 'Premium API Access'. All doc pages return only 'Connect wallet' with no content.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific function of /api/v1/policies/23 ('Premium API Access') is undefined — it is unclear what data or service it provides
- —No request or response examples available anywhere in crawled content
Citations
- —Endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/policies/23
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/policies/23