Pay-per-call premium API access on Base via x402 — $0.02 per request in USDC.
What it does
lowpaymentfee.com offers a suite of pay-per-request API endpoints gated by the x402 protocol on the Base network. The specific endpoint at `/api/v1/charges/101` is labeled "Premium API Access" and accepts payment in USDC (contract 0x8335…2913 on Base). The x402 challenge advertises a maxAmountRequired of 20,000 base units, which at 6 decimals for USDC equals $0.02 per request.
The broader platform lists 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 advertised at $0.02 per request with no API keys, no rate limits, and no minimum commitments.
Documentation 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 documentation, and no usage examples available from the crawl. The `/api/v1/charges/101` endpoint itself does not clearly map to any of the listed API categories, so its exact functionality beyond the "Premium API Access" label is unknown.
Capabilities
Use cases
- —Accessing data analytics and reports on a per-request payment basis without subscriptions
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with per-call USDC payments
- —Fetching financial data like exchange rates, token quotes, and gas estimates via x402
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments in USDC on Base
- —Projects needing quick access to utility APIs without API key management
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Anyone unable to pay in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/101 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schemas, no examples, and the specific function of /api/v1/charges/101 is unclear beyond its label.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all render only 'Connect wallet'
- —No OpenAPI or schema definitions found
- —The exact functionality of /api/v1/charges/101 ('Premium API Access') is not described anywhere
- —No request or response examples available
- —The listed API categories (AI, analytics, finance, utils) are advertised but none have documented schemas
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/101
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs