Pay-per-call API platform on Base via x402 — $0.02/request for data, AI, finance, and utility endpoints.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request 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 at $0.02 per request and settle in USDC on the Base network.
The specific endpoint at `/api/v1/payments/213` is listed as "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02. Payment is made via the x402 exact scheme — no API keys, subscriptions, or rate limits are required. The endpoint accepts POST requests and returns application/json.
Documentation is extremely sparse: the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available. The actual functionality behind the `/api/v1/payments/213` "Premium API Access" endpoint is unclear — it may be a generic payment or access endpoint rather than one of the named service endpoints listed on the homepage. Without documentation, the exact input parameters and response format cannot be determined.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data (prices, exchange rates, gas estimates) with per-call USDC payments
- —Running utility operations (geocoding, validation, conversion) on a pay-as-you-go basis
- —Integrating agent-purchasable API calls into autonomous workflows via x402
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents that can settle payments autonomously via x402 on Base
- —Projects needing low-cost micropayment-gated endpoints without subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume use cases where per-request pricing may not be cost-effective
- —Developers without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/213 \
-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, confirming pricing and payment details. However, documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no examples. The purpose of the specific /api/v1/payments/213 endpoint is unclear beyond its title.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) contain no usable content — only a 'Connect wallet' prompt.
- —No OpenAPI or schema documentation is available for any endpoint.
- —The specific endpoint /api/v1/payments/213 ('Premium API Access') does not correspond to any of the named service endpoints listed on the homepage; its actual functionality is unknown.
- —Request and response formats are entirely undocumented — integration requires trial and error.
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base network.https://lowpaymentfee.com/api/v1/payments/213
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com
- —Documentation pages render only a 'Connect wallet' prompt with no further content.https://lowpaymentfee.com/docs