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. The specific endpoint path (`/api/v1/stripe/subscriptions/95`) suggests a subscription-tier resource, though the crawled site primarily advertises a flat per-request pricing model across many API categories. The endpoint is live and returns a valid x402 challenge requesting payment in USDC on the Base network.
The x402 challenge specifies a maximum amount of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this converts to $0.02 per request, consistent with the site's advertised pricing of $0.02/request across all endpoints. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader lowpaymentfee.com platform lists endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure (geocoding, validation, conversion, generation). All are priced at $0.02/request with no API keys, no rate limits, and no commitments. However, the specific functionality behind this particular subscription endpoint is not documented in the crawled material, and the docs/pricing/API pages all returned only a "Connect wallet" prompt with no additional content.
Capabilities
Use cases
- —Accessing premium API resources with per-call USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic subscription or premium-tier resource retrieval
Fit
Best for
- —Developers wanting no-signup, pay-per-request API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over traditional API key subscriptions
Not for
- —Users who need detailed API documentation before integrating
- —Applications requiring free or fiat-only payment methods
- —High-volume use cases where $0.02/request adds up significantly
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/subscriptions/95
# Returns 402 with x402 challenge; attach X-PAYMENT header with USDC payment proof on Base to access.Example
Response
{
"error": "X-PAYMENT header is required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://lowpaymentfee.com/api/v1/stripe/subscriptions/95",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}Endpoint
Quality
The endpoint is live with a valid x402 challenge and clear pricing ($0.02 USDC on Base), but there is no documentation of what this specific endpoint returns upon successful payment. The docs, pricing, and API pages are all blank beyond a wallet-connect prompt. The endpoint path suggests subscription functionality but no schema or examples exist.
Warnings
- —No documentation available for what this endpoint returns after successful payment
- —Docs, pricing, and API pages all render only a 'Connect wallet' prompt with no content
- —The endpoint path references 'stripe/subscriptions' which is unusual for a crypto-settled x402 endpoint — actual behavior is unclear
- —No OpenAPI schema or input/output examples available
Citations
- —The x402 challenge requests 20,000 base units of USDC (=$0.02) on Base network with a 300-second timeouthttps://lowpaymentfee.com/api/v1/stripe/subscriptions/95
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/stripe/subscriptions/95