I would look into https://iexcloud.io/ as well. I used their excellent set of APIs to build https://stockdaddy.io/

Pretty cool site, like the simple layout.

Eh, no websocket for prices? I like finnhub (https://finnhub.io) or alpaca (https://alpaca.markets/) better.

public websockets API? Doesn't that introduce a lot of scaling issues for the API provider?

Not really. A websocket is "just" a TCP connection.

If the API provider is using a language+framework that can't easily handle lots of concurrent TCP connections, then yes, that could cause scaling issues, but... that's a choice.

There are plenty of ways to build scalable socket servers, and it's especially feasible in languages like Go and Elixir.

i thought websocket pattern requires statefulness on the server side. That's the finite constraint that I'm thinking of.

Server side state can take many forms. In general, you already have to track state per customer anyways, and that often goes in a database. You can also keep per client state in the database too, if it won’t fit in memory for some reason.

idk, it all depends on what you’re using the websockets for. If you have to send messages from one websocket client to another, things can get harder because those two websockets might not be connected to the same server.

It does, but it doesn’t have to. :) https://fanout.io

(Disclosure: founder)

I forgot to write "a [free] alternative to Yahoo Finances"

A free API key is great, but what is the catch? The whole Robinhood drama about them selling data to third parties has me leery about anything "free" in finance SaaS.

Robinhood drama isn't "selling data" it's selling access to fulfill bids.

It's akin ordering delivery from a store and having Instacart be the only option.

Most of the drama was misinformed speculation. A bit was suspicion that the order fulfiller was untrustworthy (because the reason they are willing to provide the service is that they know you will make bad trades, so what happens if you make a good trade that makes them lose money?)

It's tiered. They have a "pay me" tier.

I totally missed that. Thanks!

edit: For those wondering what the price is it's on this page https://www.alphavantage.co/premium/ which is not very apparent from the front page.

They mention they are “partnered with” https://polygon.io/stocks and send you there for real time.

Sadly the limits for the free tier look too low to even run this CLI ticker application off of it (or is it possible to query more than one symbol in one API call?).

FWIW, last year I was playing with this API and they were not verifying the key properly: just appended anything at the end of the key and it worked.

I cant find any info regarding this, but do they have data on global exchanges? More specifically those in Asia?

What would you say pros and cons are compared to yahoo?

It's a supported API, with free and paid plans. The Yahoo API has been officially dead for years, they just didn't pull the plug yet.

Yeah, the state of Yahoo is really strange. It's still the best free one I've found. Why I'm looking for alternatives..