x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-protocol API marketplace that gates access to a variety of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint at `/api/v1/cards/29` is listed as "Premium API Access" and costs $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 exact scheme — no API keys, no rate limits, and no subscriptions required.
The broader platform advertises four categories of APIs: 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 listed at the same $0.02 per request price point. The endpoint accepts HTTP POST requests and returns application/json responses.
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 schema, no request/response examples, and no detailed documentation available from the crawl. The exact functionality behind the `/api/v1/cards/29` path is unclear; the generic "Premium API Access" label does not describe what data or service it provides. Agents should be aware that without documentation, the request body format and response structure are unknown.
Capabilities
Use cases
- —Paying per-request for API access without subscriptions or API keys
- —Programmatic agent-driven API consumption with on-chain micropayments
- —Accessing data, AI, finance, or utility services via x402 protocol
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost per-call API access without signup
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
# The endpoint requires an x402 payment header (USDC on Base, $0.02/call)
curl -X POST https://lowpaymentfee.com/api/v1/cards/29 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the specific purpose of /api/v1/cards/29 is undefined beyond the generic label 'Premium API Access'. Docs pages return only 'Connect wallet' with no content.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request/response formats
- —The specific function of /api/v1/cards/29 ('Premium API Access') is undefined — unclear what data or service it returns
- —No request body format or response examples available from any source
Citations
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/cards/29
- —Platform lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories all at $0.02/requesthttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/cards/29
- —Docs, pricing, API, and README pages render only 'Connect wallet'https://lowpaymentfee.com/docs