x402-gated premium API access on Base, paid per-request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The specific resource at `/api/v1/charges/91` accepts POST requests and charges up to $0.02 per call in USDC (USD Coin), settled on-chain to a Base address. Payment is handled via the x402 protocol — no API keys, accounts, or rate limits are required; callers simply attach an X-PAYMENT header with a valid payment proof.
The broader lowpaymentfee.com platform advertises a suite of endpoints spanning 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 functionality behind `/api/v1/charges/91` — labeled only as "Premium API Access" — is not documented in detail. No OpenAPI schema, request/response examples, or detailed docs were found in the crawl.
The endpoint is live and returns a well-formed x402 challenge (HTTP 402) with version 1 of the protocol. The asset used for payment is USDC on Base (contract 0x8335…2913), with a maximum amount of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The timeout for payment settlement is 300 seconds.
Capabilities
Use cases
- —Agents that need to call a premium API without pre-registering for API keys
- —Pay-per-request access to backend services settled in USDC on Base
- —Programmatic access to a gated resource with on-chain payment proof
Fit
Best for
- —Developers or agents wanting keyless, pay-as-you-go API access
- —x402-compatible wallets and agent frameworks on Base
- —Low-cost micropayment use cases at $0.02 per call
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Use cases requiring free or subscription-based pricing models
- —Callers who cannot produce x402 payment proofs on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/91 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but the specific functionality behind /api/v1/charges/91 is undocumented. No OpenAPI schema, request/response examples, or detailed docs are available. The crawled pages beyond the landing page returned only 'Connect wallet' stubs.
Warnings
- —The exact functionality of /api/v1/charges/91 ('Premium API Access') is not documented — it is unclear what data or service it returns.
- —No OpenAPI spec, request body schema, or response schema was found.
- —Documentation, pricing, API, and README pages all returned only 'Connect wallet' with no substantive content.
- —The broader platform lists many endpoints (AI, finance, data, utils) but none map directly to /api/v1/charges/91.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/91
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/91
- —All endpoints on the platform are listed at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform advertises endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com