Pay-per-call API platform on Base (USDC) via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. Every endpoint costs $0.02 per request, paid in USDC on the Base network. The x402 protocol means there are no API keys, no sign-ups, and no rate limits — callers simply attach a payment header to each request.
The specific endpoint at `/api/v1/charges/332` is listed as "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation pages (docs, pricing, README) returned only a "Connect wallet" prompt with no actual technical documentation, so the exact request/response schemas for this and other endpoints are unknown.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time crypto token quotes, gas estimates, and exchange rates via micropayment
- —Geocoding and data validation as lightweight utility calls in automated pipelines
- —Exporting analytics data or generating insights reports on a per-request billing model
Fit
Best for
- —AI agents that need keyless, pay-as-you-go access to diverse API endpoints
- —Developers prototyping with multiple API categories without subscription commitments
- —Web3-native applications already operating on the Base network with USDC
Not for
- —High-volume production workloads where $0.02/request adds up significantly compared to subscription APIs
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/332 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but all documentation pages returned only 'Connect wallet' with no technical content. There is no OpenAPI spec, no request/response schema, and no description of what this specific endpoint actually returns. The listing is effectively a stub with pricing info.
Warnings
- —No API documentation available — docs, pricing, and README pages all return only 'Connect wallet'
- —No request or response schema provided for /api/v1/charges/332 or any other endpoint
- —The endpoint path '/api/v1/charges/332' with description 'Premium API Access' does not clearly map to any of the advertised API categories on the homepage
- —Actual functionality behind this endpoint is unknown — it may be a generic charge endpoint rather than a specific service
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/charges/332 requires up to 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/charges/332
- —Platform advertises endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com
- —Documentation pages returned only 'Connect wallet' with no technical contenthttps://lowpaymentfee.com/docs