x402-gated premium API access on Base, pay $0.02 per request in USDC — no keys, no rate limits.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The site hosts a broad catalog of pay-per-call APIs 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, settled in USDC on Base.
The specific endpoint `/api/v1/inbox/68` is listed as "Premium API Access" with a maximum payment of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02. Payment is made via the x402 exact scheme — callers attach an X-PAYMENT header with a signed payment to the payTo address. No API keys are required, there are no stated rate limits, and access is instant once payment is included.
Note that the endpoint path `/api/v1/inbox/68` does not clearly map to any of the named API categories on the site's landing page (analytics, AI, finance, infrastructure). The crawled documentation is extremely thin — the /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no documentation describing what this specific inbox endpoint accepts or returns. Treat this as a low-documentation endpoint where the actual functionality behind the paywall is uncertain.
Capabilities
Use cases
- —Programmatic access to a pay-per-call API without managing API keys or subscriptions
- —Agent-driven workflows that need to pay for API calls on-the-fly using USDC on Base
- —Testing x402 payment flows against a live, low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —AI agents that need keyless, pay-as-you-go API access
- —Low-volume consumers who want per-request billing with no commitments
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume production workloads where per-request crypto settlement overhead matters
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/68 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no documentation explaining what /api/v1/inbox/68 actually does. The 'Premium API Access' label is generic and the inbox path doesn't match any documented API category. Effectively a stub listing.
Warnings
- —No documentation available for /api/v1/inbox/68 — the endpoint's actual functionality is unknown
- —No OpenAPI schema or request/response examples provided
- —The /api, /pricing, and /README pages returned only 'Connect wallet' with no useful content
- —The path '/api/v1/inbox/68' does not correspond to any named API on the site's landing page
Citations
- —The site lists APIs across data & analytics, AI & ML, finance & Web3, and infrastructure categories, all priced at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02 per request with no API keys, no rate limits, instant access, on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/inbox/68