wealthsimple-prometheus

Please note: Do not run this facing the internet, unless you're fine with the whole world seeing how much money you've got in the bank.

This is a pretty simple service thing that polls Wealthsimple for account data and makes it available for Prometheus to pull it in.

Currently, there are four gauges:

• wealthsimple_deposited: The total amount of money that has been deposited
• wealthsimple_withdrawn: The total amount of money that has been withdrawn
• wealthsimple_net_liquidation: The value were all assets to be liquidated
• wealthsimple_gross_position: The sum of all positions

Each of these gauges is tagged with the following:

• account_id: The account identifier within Wealthsimple
• account_type: The type of account
• account_name: The nickname of the account

This is only scratching the surface, though. Take a look at the api docs to see some of the other cool stuff that maybe works.

Usage

To use this, all you need to do is clone the repo and run cargo run inside it. You could use a release build, but I don't think there's much concern about performance here... (it spends most of the time sleeping).

When you run it, it'll prompt you for your credentials. These aren't stored anywhere (which means you'll have to enter it every time you restart it), and the password prompt is an actual password prompt (the text you type is not displayed). If you have 2FA set up (which you probably should), you'll be prompted for a one-time password as well. You shouldn't have to enter the a 2FA code again for the life of the program (unless it runs more than 30 days), since it passes the same remember=true as the actual Wealthsimple browser client.

Once it's running, you can point Prometheus at it. Currently it always just runs on port 8080.

This is how I've got it configured:

scrape_configs:
  - job_name: 'wealthsimple'
    static_configs:
    - targets: ['localhost:8080']

How it works

There are two threads: One to poll Wealthsimple forever, and one to serve requests to the /metrics resource forever.

I've avoided unwrap()-ing anything so that this will be reliable, but there are plenty of places where errors are propagated, which will instantly terminate the program. We'll consider improving this a TODO.

In the polling loop, the following happens:

1. A request is made to https://api.production.wealthsimple.com/v1/accounts to get a list of the user's accounts.
2. If the request came back as a 401, the auth token probably expired, so get a new one and try again.
3. Some choice information is shoved into the gauges we mentioned earlier.
4. Sleep for 5 minutes.

The server loop is even simpler:

1. Get the next request.
2. Return a 404 status if it's not for /metrics.
3. Encode the gauge data into Prometheus-speech.
4. Send it back.

Why?

I'm not a fan of how Wealthsimple graphs your accounts by default. I don't really care that the value of my account has increased due to my deposits; it just makes it more difficult to read the changes in returns.

Keep in mind I'm no financier, I mostly just like pretty graphs. If you're anything like me, this is the query you're looking for (probably; I'm a data noob):

(((wealthsimple_net_liquidation - wealthsimple_withdrawn) / (wealthsimple_deposited - wealthsimple_withdrawn)) - 1) * 100