> ## Documentation Index
> Fetch the complete documentation index at: https://qi.alphakdb.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

**qi.q** is a package manager for **q**. It can be fetched with:

**Linux / Mac:**

```bash theme={null}
curl -LO https://alphakdb.com/qi.q
```

**Windows:**

```powershell theme={null}
Invoke-WebRequest -Uri https://alphakdb.com/qi.q -OutFile qi.q
```

or by copying from [alphakdb.com/qi.q](https://alphakdb.com/qi.q).

## Loading qi packages

To load a package, use **.qi.import**:

```q theme={null}
/ Example hello.q

\l qi.q
.qi.import`log
.qi.import`cron

hello:{.log.info"Hello, world";}

.cron.add[`hello;.z.p;00:00:01]
.cron.start[]
```

You can also specify the name of a package at the command line:

```q theme={null}
q qi.q cron   
```

A full list of packages may be found [here](/packages).

## Feed handlers

The first time you try to run a feed handler on any given machine, it will likely complain

```q theme={null}
q qi.q binance
```

due to missing environment variables and/or dependencies. If it fails, qi will create a profile file at `~/.qi/qi.profile` and suggest an alias `qi`, which will allow the feed handler to run smoothly the next time around. This extra step should only be required **once per machine**.

With a feed running, the function `tcounts[]` shows the count of each table.

If you run into issues with Github rate limiting, see [here](github).

## Other feeds

Some feeds require an account (free) and an API key. The following examples will use the `qi` alias instead of `q qi.q`.

```q theme={null}
qi kraken       / no key required
qi massive      / formerly polygon.io, key required
qi alpaca       / key and secret required
```

For information on how to configure keys, see [here](configuration#api-keys).

## Using stacks

q processes usually work together as a *stack*. The tickerplant (**tp**) is a router that takes data from feeds, and manages subscriptions. To start a **tp** as part of a stack, run:

```q theme={null}
qi tp1
```

The `1` (or any suffix) tells qi that this is a process that lives in a stack. Because no stack has been created, qi will create an example stack **dev1**, and will place a JSON configuration file in a **stacks** folder in the current working directory.

Other useful commands:

```q theme={null}
qi rdb1              / start a real time database in the foreground
qi up wdb1           / start a write database in the background
qi up dev1           / start the whole dev1 stack in the background
qi down kraken1      / bring the kraken feed down
qi status dev1       / show the status of dev1's processes
```

When a feed handler is started in process mode (e.g. binance1), it publishes updates to its assigned tickerplant instead of accumulating data locally.

## Hub

The hub process provides a view of all other processes:

```q theme={null}
qi hub
```

The hub contains a `procs` table that lists the various processes. From within the hub, you can control processes and stacks:

```q theme={null}
q)up `tp1
q)down `rdb1
q)up `dev1      / bring up the whole stack
q)down `dev1
```

Other useful hub functions:

```q theme={null}
q)readstack`dev1
q)clonestack[`dev1;`dev3]
q)renamestack[`dev3;`dev4]
q)deletestack`dev4
```

## License

**qi.q** and its packages are free to use, and distributed under the [MIT license](https://opensource.org/license/mit).

## Questions & Feedback

* Email: [qi@alphakdb.com](mailto:qi@alphakdb.com)