Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com offers a suite of pay-per-request API endpoints gated by the x402 protocol on the Base network. This specific endpoint (`/api/v1/transactions/209`) is listed as "Premium API Access" and accepts POST requests. Payment is settled in USDC (contract `0x8335…2913` on Base) at a cost of $0.02 per call (20,000 base units with 6 decimals). No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
The broader platform advertises endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced uniformly at $0.02 per request.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/transactions/209` endpoint actually returns. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is unclear what data or functionality this specific resource provides.
Capabilities
Use cases
- —Programmatic access to premium data or services without API key registration
- —Agent-driven workflows that need instant, keyless API access settled in USDC
- —Exploring x402 protocol integration for pay-per-call microservices
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —Agents that can attach x402 payment headers and settle in USDC
- —Use cases requiring no-signup, no-rate-limit API access
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —Production workloads requiring SLA guarantees or support channels
- —Callers who cannot settle payments in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/209 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty stubs. The purpose of this specific endpoint (/api/v1/transactions/209) is entirely undocumented, making it effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content.
- —The specific purpose and expected input/output of /api/v1/transactions/209 is unknown; 'Premium API Access' is the only description provided.
- —No OpenAPI schema or response examples are available anywhere on the site.
- —The platform lists many endpoint categories (AI, finance, analytics, infrastructure) but provides zero detail on any of them.
Citations
- —Endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 in USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/209
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/209
- —Platform advertises endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com