
Public market-depth and sized exit estimates, not executable quotes.
Undertow API is a free Finance API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Read-only API, MCP and x402 access to the liquidity board, exit costs and sealed evidence record.
Details from liquilens-undertow.com.

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Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
The Undertow API is provided by Undertow · by LiquiLens (liquilens-undertow.com). Read-only API, MCP and x402 access to the liquidity board, exit costs and sealed evidence record.
Yes. The Undertow API is listed in the Finance category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The Undertow API requires no authentication, so you can start making requests without signing up.
Yes. The Undertow API supports CORS, so front-end JavaScript can call it directly.
Yes. The Undertow API is served over HTTPS, so it's safe to use in production.