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 broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request using USDC on the Base network at a flat rate of $0.02 per call, with no API keys, no rate limits, and no commitments required.
The specific endpoint at `/api/v1/transactions/158` is listed as "Premium API Access" and returns an x402 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, settling to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The endpoint accepts HTTP POST 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 data generation — all at the same $0.02 price point. However, documentation beyond the landing page is essentially empty (all sub-pages just show "Connect wallet"), so the actual request/response schemas for this and other endpoints are unknown. Without documentation or OpenAPI specs, callers must discover behavior experimentally.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to analytics, AI, finance, or utility endpoints
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-friction micropayment-gated endpoints
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who need bulk pricing or subscription discounts
- —Developers not set up for USDC payments on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/158 \
-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. However, there is no OpenAPI spec, no documentation of request/response schemas, and all doc pages are empty stubs. The purpose of this specific endpoint (/transactions/158) is unclear beyond the generic label 'Premium API Access'. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all doc/pricing/README pages return only 'Connect wallet'
- —The specific purpose and expected input/output of /api/v1/transactions/158 is undocumented
- —Cannot verify what data or service this endpoint actually provides
- —The broader platform lists many endpoints but none have documented schemas
Citations
- —Flat pricing of $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/158
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com