x402-gated premium API access on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The site offers a broad catalog of pay-per-call API endpoints spanning data & analytics, 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, payable in USDC on Base with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/charges/261` is labeled "Premium API Access" in the x402 challenge. The challenge advertises 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 with a 300-second timeout. The endpoint accepts HTTP POST requests and returns application/json.
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 spec, no request/response schema documentation, and no examples of what this particular endpoint actually returns. The site's landing page lists many endpoints but provides no detail on request parameters or response formats for any of them. Without documentation it is unclear what specific functionality the `/api/v1/charges/261` path provides beyond the generic "Premium API Access" label.
Capabilities
Use cases
- —Accessing paid API services without API key registration
- —Making one-off API calls with per-request USDC micropayments
- —Agent-driven programmatic access to gated endpoints on Base
Fit
Best for
- —Developers wanting frictionless pay-per-use API access without subscriptions
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —High-volume use cases where per-request pricing may add up
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/261 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is virtually no documentation: no OpenAPI spec, no request/response schemas, no examples, and the specific functionality behind '/api/v1/charges/261' is undefined beyond a generic label. The docs, pricing, and README pages are all empty wallet-connect stubs.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition for request parameters or response format
- —The specific functionality of /api/v1/charges/261 ('Premium API Access') is undefined; it does not match any of the named endpoints listed on the landing page
- —Cannot verify what data or service this endpoint actually provides
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with 300-second timeouthttps://lowpaymentfee.com/api/v1/charges/261
- —Site offers endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com