The Arp Index

Hmm. Can’t seem to get any companies downloaded. Internet is up and running. Restarted after install. Maiden repl says:

|Error proessing companies|[]|
|Got companies|0|

Any ideas?

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Capitalism meets tech meets synthesizers? I’m in.

This is such a wonderfully novel concept, and it could actually inspire some interesting melodies for when I’m feeling undecided but don’t want to just play a random arpeggiator or up/down on a favorite chord.

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Good question, it seems the API is returning no results today - I’ll ask about it.


Sounds like it was something to do with the markets being closed for the US bank holiday :chart_with_downwards_trend:

Should be working again now everyone is back buying & selling :chart_with_upwards_trend:


Here’s a video showing a MIDI keyboard controlling the generated pattern and MIDI output (to CV) driving an external synth. The Arp Index plays nicely with others. :two_men_holding_hands:


This is super cool. 20 step 1 day pattern for Boeing is quite the descending line post 737 MAX + Starliner + firing CEO.

I see you have an API key for the stock data in the source code, which is fine but might break the script in the future. Is it possible to use import system env vars from the we user into Norns Lua? My python is much more strong today but something like putting IEXAPIS_TOKEN in .bashrc and then

import os
API_KEY = os.environ['IEXAPIS_TOKEN']
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Has anyone come across “error: init” when trying to run this? I’ve installed it via maiden. I get the same error from molly the poly

@voidstate Is there some console output in maiden?

@lazzarello not sure I really follow your suggestion here – if it’s about getting the API key out of the main script then why not just a lua file?

No it installs fine, when I run it on norns I get the initial screen ok then it kicks me back to the main menu with “error init” where the app name usually displays.

I was wondering about output when running the script?

lua version

API_KEY = os.getenv('IEXAPIS_TOKEN')
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I ran it in maiden and downloaded it to norns from there and now it works. Resolved!

@zebra lol, thanks. that makes a lot of sense.

@markeats just a different place to put it. It was a reflex from working with web APIs a lot. It could go anywhere really. It’s nbd.

Today was a bad day for stonks, but it was a good day to use arp_index. I’m using it here to sequence my Deepmind 12D.


Hi, this is really nice. I love it! Would there be anyway to track other stock echanges as an option?

not sure how exactly it’s being done, but looking at the code - it pulls data from

and specifically gets companies from this line.

So you could probably setup your own API token and company list?

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Hi okyeron,
Not sure how I can do what you suggest, but I’ll try that at some point.
Thanks for the quick reply!

Yep @okyeron is spot on, there are lots of options with their API that would easily swap in, eg:


Thanks, but this is way above my capabilities at this time, but I appreciate the suggestion.


Is tempo adjustable?