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/79` is one of many endpoints offered by the provider, which hosts a broad catalog 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, paid in USDC on the Base network with no API keys, rate limits, or commitments required.
The x402 challenge confirms the endpoint is live and accepts POST requests. Payment is settled on-chain using USDC (contract 0x8335…2913) on Base, with a max amount of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The payment timeout is 300 seconds. No OpenAPI schema, detailed documentation, or example request/response payloads were found beyond the landing page catalog listing.
Because the specific endpoint path `/api/v1/inbox/79` does not appear in the provider's public catalog (which lists paths like `/api/v1/analytics/metrics`, `/api/v2/ai/sentiment`, etc.), its exact functionality is unclear. The title "Premium API Access" is generic and does not describe a specific capability. Users should treat this as an opaque paid endpoint until more documentation is available.
Capabilities
Use cases
- —Programmatic access to paid API services without traditional API key registration
- —Agent-driven workflows that need on-demand, per-call payment via x402
- —Testing x402 payment flows on Base with low-cost USDC transactions
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 no-commitment per-request pricing
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume production workloads requiring bulk pricing or rate guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/79 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but the specific endpoint /api/v1/inbox/79 is not documented in the provider's public catalog. No OpenAPI schema, request/response examples, or detailed docs are available. The endpoint's actual functionality is unknown.
Warnings
- —The path /api/v1/inbox/79 does not appear in the provider's public API catalog — its purpose is undocumented.
- —No OpenAPI spec, request schema, or response schema is available.
- —The /api, /pricing, and /README pages returned only a 'Connect wallet' prompt with no useful content.
- —Exact functionality behind 'Premium API Access' is unspecified.
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —Provider offers endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units in USDC on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/inbox/79
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/inbox/79