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 specific path `/api/v1/inbox/195` is one of many endpoints offered by the provider, which hosts a broad catalog spanning data & analytics, AI & machine learning (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 minimum commitments.
The x402 challenge confirms the endpoint is live, accepting POST requests and requiring an exact-scheme payment of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals = $0.02) per call. The payment is directed to wallet 0x1A2B…85F3 with a 300-second timeout. The response MIME type is application/json.
Note that the specific functionality behind `/api/v1/inbox/195` is not documented on the provider's landing page — it is labeled only as "Premium API Access" without further detail on what data or service it returns. The provider's other endpoints are categorized and described, but this particular inbox endpoint lacks documentation. Users should be aware that the exact input/output schema is unknown beyond the JSON content type.
Capabilities
Use cases
- —Programmatic access to a premium API endpoint with per-request USDC micropayments
- —Agent-driven workflows that need keyless, pay-as-you-go API access on Base
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —AI agents that need frictionless, keyless API access
- —Users who want to avoid subscriptions and pay only per request
Not for
- —Users who need detailed documentation or guaranteed SLAs for the inbox endpoint
- —Anyone without a Base-compatible USDC wallet
- —High-volume use cases where $0.02/request adds up significantly
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/195 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/inbox/195",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-token>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but the specific endpoint /api/v1/inbox/195 has no documentation, no input/output schema, and no description beyond the generic 'Premium API Access' label. The provider's landing page documents other endpoints but not this one, making it effectively a stub listing.
Warnings
- —The specific endpoint /api/v1/inbox/195 is not documented on the provider's site — its purpose and expected input/output are unknown.
- —No OpenAPI spec, no request/response schema, and no examples are available for this endpoint.
- —The provider's /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content.
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 (6 decimals = $0.02) on Basehttps://lowpaymentfee.com/api/v1/inbox/195
- —Provider offers endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com