Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network via the x402 payment protocol. No API keys, accounts, or rate limits are required — callers simply attach an X-PAYMENT header with a valid payment proof.
The specific endpoint at `/api/v1/transactions/377` is listed as "Premium API Access" and returns `application/json`. The x402 challenge confirms it accepts POST requests, charges a maximum of 20,000 base units of USDC (0.02 USD given 6 decimals) per call, and pays out to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base. The payment timeout is 300 seconds.
The broader platform advertises additional endpoints including 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 beyond the landing page returned only a "Connect wallet" prompt with no further technical detail, so the actual behavior, request schemas, and response formats of these endpoints remain undocumented in the crawled material.
Capabilities
Use cases
- —Agents needing on-demand API access without API key registration
- —Programmatic access to analytics, AI inference, or financial data with per-call USDC micropayments
- —Web3 applications that want to consume utility endpoints (geocoding, validation, conversion) paid via on-chain settlement
Fit
Best for
- —Developers or agents wanting zero-signup, pay-as-you-go API access
- —Low-volume or bursty workloads where $0.02/request is cost-effective
- —x402-compatible agent frameworks that can attach payment headers automatically
Not for
- —High-volume production workloads where per-request pricing becomes expensive
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
- —Callers without USDC on Base or an x402-compatible payment client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/377 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and all documentation pages beyond the landing page are empty ('Connect wallet' only). The purpose of the specific /transactions/377 endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —No API documentation available — all doc pages return only 'Connect wallet' with no technical content
- —The specific purpose and expected request/response format of /api/v1/transactions/377 is undocumented
- —No OpenAPI spec, no request schema, and no response examples are provided
- —The broad endpoint catalog (AI, finance, utilities) is advertised but none could be verified beyond the landing page listing
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base network, maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/transactions/377
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/377
- —Platform lists endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com