I don't see a TOS page on the site. Where is its (corporation?) owner domiciled? I can appreciate the hustle of bootstrapping a site, but how can anyone know the site has appropriate redistribution agreements in place with those exchanges? Can you cite feed and/or entitlement names that you are redistributing from NASDAQ for example? I wouldn't want to invest time writing against an API that could get shutdown without warning due to misuse of an upstream source.

When it can't match the ticker from request, it returns randomly selected from {FB, TSLA, AAL, AAPL, MSFT}

https://www.styvio.com/api/nada

Thanks for pointing that out. Would you mind expanding a little into the real time aspect of the API?

Does that includes order and Level 2?

Not yet, we are currently in the process of adding those features, as well as dark pool order data, and options data!

Where are you getting dark pools from? That’s usually intentionally not publicly visible.

It is visible a day or two after, and FINRA provides an API to access the data. We plan on working with FINRA to add dark pool data to our API and visualizer tools.

Oh that's interesting, I'll have to take a look. So far most of what I want is available from TD Ameritrade's API, which while it isn't pretty, it does work pretty well.