Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The site hosts a broad catalog of pay-per-request APIs spanning data & analytics, AI/ML inference (sentiment analysis, 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, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/charges/36` is listed as "Premium API Access" and returns a standard x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme to the specified payTo address, with a 300-second timeout. The endpoint accepts HTTP POST requests and returns application/json.
Documentation is extremely sparse — the docs, API, pricing, 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 detailed description of what this particular endpoint returns or what input it expects. The endpoint is confirmed live (402 challenge captured), but without documentation it is unclear what specific data or functionality "Premium API Access" provides beyond the generic label.
Capabilities
Use cases
- —Paying per-call for API access without needing API keys or subscriptions
- —Integrating x402-compatible agents with a low-cost pay-per-request endpoint
- —Accessing premium data or services with USDC micropayments on Base
Fit
Best for
- —Agents or developers wanting zero-commitment, pay-as-you-go API access
- —x402-native workflows that settle in USDC on Base
- —Low-cost experimentation with per-request pricing at $0.02
Not for
- —Users who need detailed API documentation or well-defined schemas before integrating
- —High-volume production workloads where the specific endpoint behavior is undocumented
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/36 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the description 'Premium API Access' is entirely generic. It is impossible to determine what this endpoint actually does from the available material.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or schema definition; request body and response format are unknown.
- —The label 'Premium API Access' is generic and does not describe specific functionality.
- —The broader site lists many endpoints but none have documented schemas or examples.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/36
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/36
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Site offers APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com