Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data & analytics, AI & machine learning, finance & Web3, and infrastructure utility categories. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required.
The specific endpoint at `/api/v1/transactions/173` is labeled "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, documentation pages (/docs, /pricing, /api, /README) all returned only a "Connect wallet" prompt with no substantive content, so the actual behavior, input schemas, and response formats for these endpoints remain undocumented and unverifiable.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless API access with crypto micropayments
- —Projects already operating on the Base L2 network
Not for
- —Users who need detailed API documentation and guaranteed SLAs
- —Applications requiring free or fiat-only payment methods
- —Production workloads needing well-documented input/output schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/173 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but documentation pages are empty (only 'Connect wallet' stubs). There is no OpenAPI spec, no input/output schema, no examples, and the purpose of this specific '/transactions/173' endpoint is unclear beyond the generic 'Premium API Access' label. The platform lists many endpoints but provides no verifiable documentation for any of them.
Warnings
- —All documentation pages (/docs, /pricing, /api, /README) returned no useful content — only a 'Connect wallet' prompt.
- —No OpenAPI or schema documentation is available for any endpoint.
- —The specific purpose and expected input/output of /api/v1/transactions/173 is unknown — 'Premium API Access' is not descriptive.
- —The actual functionality behind the advertised AI, finance, and utility endpoints cannot be verified from available materials.
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/transactions/173 requests up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with a 300-second timeout.https://lowpaymentfee.com/api/v1/transactions/173
- —The platform advertises endpoints for analytics, AI/ML, finance, and infrastructure utilities.https://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) returned only 'Connect wallet' with no substantive content.https://lowpaymentfee.com/docs