Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and general utility services. All endpoints are paid per-request using USDC on the Base network via the x402 protocol — no API keys, no rate limits, and no subscriptions required.
The specific endpoint at `/api/v1/transactions/133` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals). The platform's landing page confirms a uniform $0.02/request pricing across all its endpoints.
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. However, documentation pages beyond the landing page returned only a "Connect wallet" prompt with no further technical detail, so the actual request/response schemas for this specific endpoint remain unknown. The endpoint is live and returning a valid 402 challenge.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes and gas estimates via micropayment
- —Running geocoding or data validation calls on a pay-as-you-go basis
- —Exporting analytics data or generating reports with per-request billing
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost micropayment-gated endpoints without subscriptions
Not for
- —High-volume production workloads needing SLAs or guaranteed uptime documentation
- —Users without USDC on Base or an x402-compatible payment client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/133 \
-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 there is no OpenAPI spec, no documentation beyond the landing page, and no request/response schema. The description 'Premium API Access' is generic and does not clarify what this specific endpoint does. All doc/pricing/readme pages returned only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —All documentation pages (/docs, /api, /pricing, /README) returned only 'Connect wallet' with no useful content
- —The endpoint path '/api/v1/transactions/133' with description 'Premium API Access' is vague; its actual functionality is unclear
- —No examples or error handling documentation found
Citations
- —Uniform $0.02/request pricing, no API keys, no rate limitshttps://lowpaymentfee.com
- —Endpoint returns 402 with x402 challenge advertising 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/133
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/133
- —Platform lists endpoints for analytics, AI, finance, and utility categorieshttps://lowpaymentfee.com