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 resource at `/api/v1/charges/254` accepts POST requests and charges up to 20,000 base units of USDC (0x8335…2913) on the Base network, which equals $0.02 per request (USDC uses 6 decimals). Payment is handled entirely through the x402 `X-PAYMENT` header — no API keys, accounts, or rate limits are required.
The broader lowpaymentfee.com platform advertises a suite of endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), 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 listed at $0.02 per request. However, the specific endpoint being listed here (`/api/v1/charges/254`) is labeled only as "Premium API Access" and its exact functionality is not documented beyond that label.
The endpoint is confirmed live — it returns a proper 402 challenge with x402 version 1 semantics, a 300-second payment timeout, and the `exact` payment scheme. Documentation on the site is extremely sparse; the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material.
Capabilities
Use cases
- —Programmatic access to premium API services without needing an API key or subscription
- —Agent-driven workflows that pay per call using USDC 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 keyless, pay-as-you-go API access
- —Low-cost per-request access without rate limits or commitments
Not for
- —Users who need detailed documentation or OpenAPI specs before integrating
- —Anyone without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/254 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality behind 'Premium API Access' at /api/v1/charges/254 is completely undocumented. The site's docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or request/response schema provided; it is unclear what this endpoint actually returns
- —The specific functionality of /api/v1/charges/254 ('Premium API Access') is not described anywhere in the crawled material
- —The broader site lists many endpoint categories (AI, analytics, finance, etc.) but none map directly to this /charges/254 path
Citations
- —Endpoint returns a 402 challenge with x402 version 1, maxAmountRequired 20000 USDC base units on Base networkhttps://lowpaymentfee.com/api/v1/charges/254
- —All endpoints listed at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/254
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs