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, paid in USDC on the Base network with no API keys, rate limits, or commitments required.
The specific endpoint at `/api/v1/charges/381` is labeled "Premium API Access" and accepts POST requests. The x402 challenge indicates a maximum amount of 20,000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme, settling 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 generation — all at the same $0.02 price point. However, documentation beyond the landing page is extremely sparse (docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content). There is no OpenAPI spec, no request/response schema documentation, and no examples available, making it difficult to know what inputs each endpoint expects or what outputs it returns.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) on a per-call basis without API keys
- —Fetching real-time crypto quotes, gas estimates, and exchange rates with micropayments
- —Running geocoding, validation, or data conversion utilities without subscription commitments
- —Exporting data or generating analytics reports paid per request in USDC
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —Agent workflows that need x402-compatible endpoints on Base
- —Users who prefer crypto-native micropayments over traditional API key subscriptions
Not for
- —Production workloads requiring detailed API documentation and SLAs
- —Users without USDC on the Base network
- —High-volume use cases where per-request pricing may be less economical than bulk plans
Quick start
# x402 POST to Premium API Access endpoint
curl -X POST https://lowpaymentfee.com/api/v1/charges/381 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page, and no examples. The 'Premium API Access' label is generic and doesn't describe what the endpoint actually does. Nearly all detail pages return only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema documentation available — request/response formats are unknown
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no substantive content
- —The endpoint name 'Premium API Access' is generic and does not describe actual functionality
- —No examples of successful responses are available anywhere in the crawl
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/381
- —Platform offers endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/381
- —Documentation pages render only 'Connect wallet' with no contenthttps://lowpaymentfee.com/docs