tconnectsync

tconnectsync

Tconnectsync synchronizes data one-way from Tandem Source to Nightscout.

[!IMPORTANT] Tandem has announced that t:connect will be shut down in favor of Tandem Source in the US beginning September 30, 2024. tconnectsync has undergone major changes to support Tandem Source. For Tandem Source support, you MUST upgrade to tconnectsync version 2.0 or above.

If you have a t:slim X2 pump with the companion t:connect mobile Android or iOS app, this will allow your pump bolus and basal data to be uploaded to Nightscout automatically. Together with a CGM uploader, such as xDrip+ or the official Dexcom mobile app plus Dexcom Share, this allows your CGM and pump data to be automatically uploaded to Nightscout!

How It Works

At a high level, tconnectsync works by querying Tandem’s undocumented APIs to receive basal and bolus data from Tandem Source, and then uploads that data as treatment objects to Nightscout. It contains features for checking for new Tandem pump data continuously, and updating that data to Nightscout whenever there is new data.

When you run the program with no arguments, it performs a single cycle of the following, and exits after completion:

• Logs in to Tandem Source
• Fetches your list of pumps, and unless overridden by an environment variable, fetches the event data for the pump which was most recently used
• Processes the internal pump event metadata to extract basal, bolus, CGM, and other pump event data
• Queries Nightscout to find the most recent data which was uploaded to it for each event category
• Uploads any missing data to Nightscout

If run with the --auto-update flag, then the application periodically looks for new data and synchronizes it to Nightscout in a loop every few minutes.

What Gets Synced

Tconnectsync is composed of individual so-called synchronization features, which are elements of data that can be synchronized between t:connect data from the pump and Nightscout. When setting up tconnectsync, you can choose to configure which synchronization features are enabled and disabled.

Here are a few examples of reasons why you might want to adjust the enabled synchronization features:

• If you currently input boluses into Nightscout manually with comments, then you may wish to disable the BOLUS synchronization feature so that there are no duplicated boluses in Nightscout.
• If you want to see Sleep and Exercise Mode data appear in Nightscout, then you may wish to enable the PUMP_EVENTS synchronization feature.
• If you want to automatically update your Nightscout insulin profile settings from your pump, then you may wish to enable the PROFILES synchronization feature.

These synchronization features are enabled by default:

• BASAL: Basal data
• BOLUS: Bolus data
• PUMP_EVENTS: Events reported by the pump. Includes support for the following:
  • Alarms, like cartridge out-of-insulin or pump malfunction
  • Basal suspension (user or pump-initiated) and resume
  • Cartridge, cannula, and tubing filled
  • Sleep and exercise modes
• PROFILES: Insulin profile information, including segments, basal rates, correction factors, carb ratios, and the profile which is active.

The following synchronization features can be optionally enabled:

• CGM: Adds Dexcom CGM readings from the pump to Nightscout as SGV (sensor glucose value) entries. This should only be used in a situation where xDrip/Dexcom Share/etc. is not used and the pump connection to the CGM will be the only source of CGM data to Nightscout. THIS WILL DELIVER CGM DATA WITH A SIGNIFICANT (>30 MINUTE) LAG AND SHOULD NOT BE USED AS A REPLACEMENT FOR DEXCOM SHARE OR OTHER REAL TIME MONITORING.

To specify custom synchronization features, pass the names of the desired features to the --features flag, e.g.:

$ tconnectsync --features BASAL BOLUS PUMP_EVENTS PROFILES

If you’re using tconnectsync-heroku, see this section in its README.

Setup

The following setup instructions assume that you have a Linux, MacOS, or Windows (with WSL) machine that will run the application continuously.

If you’ve configured Nightscout before, you may be familiar with Heroku. You can opt to run tconnectsync with Heroku by following these instructions.

To get started, you need to choose whether to install the application on your computer via Pip, Pipenv, or Docker.

After that, you can choose to run the program continuously via Supervisord or on a regular interval with Cron.

NOTE: If you fork the tconnectsync repository on GitHub, do not commit your .env file. If pushed to GitHub, this will make your tconnect and Nightscout passwords publicly visible and put your data at risk.

Installation

First, you need to create a file containing configuration values. The name of this file will be .env, and its location will be dependent on which method of installation you choose. You should specify the following parameters:

# Your credentials for t:connect
TCONNECT_EMAIL='[email protected]'
TCONNECT_PASSWORD='password'

# OPTIONAL: Your region (US or EU)
TCONNECT_REGION=US

# URL of your Nightscout site
NS_URL='https://yournightscouturl/'
# Your Nightscout API_SECRET value
NS_SECRET='apisecret'

# Current timezone of the pump
TIMEZONE_NAME='America/New_York'

# OPTIONAL: Your pump's serial number (numeric)
PUMP_SERIAL_NUMBER=11111111

This file contains your t:connect username and password, Tandem pump serial number (which is utilized in API calls to t:connect), your Nightscout URL and secret token (for uploading data to Nightscout), and local timezone (the timezone used in t:connect). When specifying the timezone, enter a TZ database name value.

(Alternatively, these values can be specified via environment variables.)

Installation via Pip

This is the easiest method to install.

First, ensure that you have Python 3 with Pip installed:

• On MacOS: Open Terminal. Install Homebrew, and then run brew install python3
• On Linux: Follow your distribution’s specific instructions.
  • For Debian/Ubuntu based distros, sudo apt install python3 python3-pip
  • For CentOS/Rocky Linux 8:
    • sudo dnf install python39-pip
    • sudo alternatives --set python /usr/bin/python3.9
• On Windows:
  • With WSL: Install Ubuntu under the Windows Subsystem for Linux. Open the Ubuntu Terminal, then run sudo apt install python3 python3-pip. Perform the remainder of the steps under the Ubuntu environment.
  • Native: Alternatively, you can run tconnectsync in native Windows with no modifications. However, this is less well-tested (open a GitHub issue if you experience any problems).

Now install the tconnectsync package with pip:

$ pip3 install tconnectsync

To install into a user environment instead of system-wide for a more contained install:

$ pip3 install --user tconnectsync

• This will place the tconnectsync binary file at /home/<username>/.local/bin/tconnectsync
• For non-WSL Windows, it will be in <PYTHON DIRECTORY>\Lib\site-packages\tconnectsync

If the pip3 command is not found, run python3 -m pip install tconnectsync instead.

After this, you should be able to view tconnectsync’s help with:

$ tconnectsync --help
usage: tconnectsync [-h] [--version] [--pretend] [-v] [--start-date START_DATE] [--end-date END_DATE] [--days DAYS] [--auto-update] [--check-login]
               [--features {BASAL,BOLUS,IOB,PUMP_EVENTS} [{BASAL,BOLUS,IOB,PUMP_EVENTS} ...]]

Syncs bolus, basal, and IOB data from Tandem Diabetes t:connect to Nightscout.

optional arguments:
  -h, --help            show this help message and exit
  --version             show program's version number and exit
  --pretend             Pretend mode: do not upload any data to Nightscout.
  -v, --verbose         Verbose mode: show extra logging details
  --start-date START_DATE
                        The oldest date to process data from. Must be specified with --end-date.
  --end-date END_DATE   The newest date to process data until (inclusive). Must be specified with --start-date.
  --days DAYS           The number of days of t:connect data to read in. Cannot be used with --from-date and --until-date.
  --auto-update         If set, continuously checks for updates from t:connect and syncs with Nightscout.
  --check-login         If set, checks that the provided t:connect credentials can be used to log in.
  --features {BASAL,BOLUS,IOB,PUMP_EVENTS} [{BASAL,BOLUS,IOB,PUMP_EVENTS} ...]
                        Specifies what data should be synchronized between tconnect and Nightscout.

Move the .env file you created to the following folder:

• MacOS: /Users/<username>/.config/tconnectsync/.env
• Linux: $HOME/.config/tconnectsync/.env
• Windows: $HOME/.config/tconnectsync/.env (inside WSL) OR C:\Users\<username>\.config\tconnectsync (native Windows)

$ tconnectsync --check-login

If you receive no errors, then you can move on to the Running Tconnectsync Continuously section.

Installing with Pipenv

You can run the application using Pipenv.

First, ensure you have Python 3 and pip installed, then install pipenv with pip3 install pipenv.

Clone the Git repository for tconnectsync and cd into it with:

$ git clone https://github.com/jwoglom/tconnectsync
$ cd tconnectsync

Then install tconnectsync’s dependencies with pipenv install. Afterwards, you can launch the program with pipenv run tconnectsync so long as you are inside the checked-out tconnectsync folder.

$ git clone https://github.com/jwoglom/tconnectsync && cd tconnectsync
$ pip3 install pipenv
$ pipenv install
$ pipenv run tconnectsync --help
usage: main.py [-h] [--version] [--pretend] [-v] [--start-date START_DATE] [--end-date END_DATE] [--days DAYS] [--auto-update] [--check-login]
               [--features {BASAL,BOLUS,IOB,PUMP_EVENTS} [{BASAL,BOLUS,IOB,PUMP_EVENTS} ...]]

Syncs bolus, basal, and IOB data from Tandem Diabetes t:connect to Nightscout.

optional arguments:
  -h, --help            show this help message and exit
  --version             show program's version number and exit
  --pretend             Pretend mode: do not upload any data to Nightscout.
  -v, --verbose         Verbose mode: show extra logging details
  --start-date START_DATE
                        The oldest date to process data from. Must be specified with --end-date.
  --end-date END_DATE   The newest date to process data until (inclusive). Must be specified with --start-date.
  --days DAYS           The number of days of t:connect data to read in. Cannot be used with --from-date and --until-date.
  --auto-update         If set, continuously checks for updates from t:connect and syncs with Nightscout.
  --check-login         If set, checks that the provided t:connect credentials can be used to log in.
  --features {BASAL,BOLUS,IOB,PUMP_EVENTS} [{BASAL,BOLUS,IOB,PUMP_EVENTS} ...]
                        Specifies what data should be synchronized between tconnect and Nightscout.

Move the .env file you created earlier into the tconnectsync folder, and run:

$ pipenv run tconnectsync --check-login

If you receive no errors, then you can move on to the Running Tconnectsync Continuously section.

Installing with Docker

First, ensure that you have Docker running and installed.

To download and run the prebuilt Docker image from GitHub Packages:

$ docker pull ghcr.io/jwoglom/tconnectsync/tconnectsync:latest
$ docker run ghcr.io/jwoglom/tconnectsync/tconnectsync --help

Move the .env file you created earlier into the current folder, and run:

$ docker run tconnectsync --check-login

If you receive no errors, then you can move on to the Running Tconnectsync Continuously section.

Building Locally

To instead build the image locally and launch the project:

$ git clone https://github.com/jwoglom/tconnectsync
$ cd tconnectsync
$ docker build -t tconnectsync .
$ docker run tconnectsync --help

Move the .env file you created earlier into this folder, and run:

$ docker run --env-file=.env tconnectsync --check-login

NOTE: If using the --env-file option to docker run, you may need to remove all quotation marks (' and "s) around values in the .env file for Docker to propagate the variables correctly.

If you receive no errors, then you can move on to the Running Tconnectsync Continuously section.

Running Tconnectsync Continuously

You most likely want tconnectsync to run either continuously (via the auto-update feature) or on a regular interval (via cron).

The supervisord approach is recommended for simplicity.

Running with Supervisord (recommended)

To configure tconnectsync to run continuously in the background using its --auto-update feature, you can use a tool such as Supervisord.

First, install supervisord via your Linux system’s package manager. (For example, for Ubuntu/Debian-based systems, run sudo apt install supervisor)

Supervisord is configured by creating a configuration file in /etc/supervisor/conf.d.

Here is an example tconnectsync.conf which you can place in that folder:

[program:tconnectsync]
command=/path/to/tconnectsync/run.sh
directory=/path/to/tconnectsync/
stderr_logfile=/path/to/tconnectsync/stderr.log
stdout_logfile=/path/to/tconnectsync/stdout.log
user=<your username>
numprocs=1
autostart=true
autorestart=true

In order to create a run.sh file, see the section below which aligns with your choice of installation method.

After the configuration file has been created, ensure that Supervisor is running and configured to start on boot:

$ sudo systemctl daemon-reload
$ sudo systemctl start supervisord
$ sudo systemctl enable supervisord

Then use the supervisorctl command to manage the status of the tconnectsync program:

$ sudo supervisorctl status
tconnectsync                     STOPPED
$ sudo supervisorctl start tconnectsync
$ sudo supervisorctl status
tconnectsync                     RUNNING   pid 18810, uptime 00:00:05

You can look at the stderr.log and stdout.log files to check that tconnectsync is running and has started up properly:

$ tail -f /path/to/tconnectsync/stdout.log
Starting auto-update between 2021-09-30 00:06:39.942273 and 2021-10-01 00:06:39.942273
2021-10-01 00:06:39 DEBUG    Instantiating new AndroidApi
2021-10-01 00:06:39 DEBUG    Starting new HTTPS connection (1): tdcservices.tandemdiabetes.com:443
2021-10-01 00:06:40 DEBUG    https://tdcservices.tandemdiabetes.com:443 "POST /cloud/oauth2/token HTTP/1.1" 200 404
2021-10-01 00:06:40 INFO     Logged in to AndroidApi successfully (expiration: 2021-10-01T08:06:40.362Z, in 7 hours, 59 minutes)

With Pip Installation

In the tconnectsync.conf, you should set /path/to/tconnectsync to the folder containing your .env file.

Create a run.sh file containing:

#!/bin/bash

tconnectsync --auto-update

With Pipenv Installation

In the tconnectsync.conf, you should set /path/to/tconnectsync to the folder where you checked-out the GitHub repository.

An example run.sh which launches tconnectsync within its pipenv-configured virtual environment:

#!/bin/bash

PIPENV=/home/$(whoami)/.local/bin/pipenv
VENV=$($PIPENV --venv)

source $VENV/bin/activate

cd /path/to/tconnectsync
exec python3 -u main.py --auto-update

With Docker Installation

In the tconnectsync.conf, you should set /path/to/tconnectsync to the folder where you checked-out the GitHub repository.

An example run.sh if you installed tconnectsync via the GitHub Docker Registry:

#!/bin/bash

docker run ghcr.io/jwoglom/tconnectsync/tconnectsync --auto-update

An example run.sh if you built tconnectsync locally:

#!/bin/bash

docker run tconnectsync --auto-update

Tuning Auto-Update

These optional environment variables control how --auto-update polls and how it behaves when things go wrong. The defaults are sensible; you generally only need these if you are seeing too many (or too few) restarts.

Variable	Default	What it does
AUTOUPDATE_DEFAULT_SLEEP_SECONDS	300	Poll interval when no better estimate is available. Also the ceiling for the retry backoff below.
AUTOUPDATE_MAX_SLEEP_SECONDS	1500	Upper bound on the adaptive poll interval, regardless of how rarely new data appears.
AUTOUPDATE_UNEXPECTED_NO_INDEX_SLEEP_SECONDS	60	How long to wait when new data is overdue based on the pump’s previous cadence.
AUTOUPDATE_USE_FIXED_SLEEP	false	Set true to always sleep AUTOUPDATE_DEFAULT_SLEEP_SECONDS instead of adapting to the pump’s observed upload cadence.
AUTOUPDATE_API_FAILURE_MINUTES	45	Exit with a non-zero code after this many minutes of unbroken API/network failure, so your container platform restarts tconnectsync and can alert you. Set 0 to never exit.
AUTOUPDATE_NO_DATA_FAILURE_MINUTES	180	Log an error if the pump has not reported new events for this long. Usually means the pump simply is not uploading.
AUTOUPDATE_FAILURE_MINUTES	75	Log an error if events are appearing but no data has synced successfully for this long.
AUTOUPDATE_RESTART_ON_FAILURE	false	Whether the two watchdogs above also exit non-zero. Independent of AUTOUPDATE_API_FAILURE_MINUTES.
AUTOUPDATE_MAX_LOOP_INVOCATIONS	-1	Stop after this many poll cycles. -1 means run forever; mainly useful for testing.

On failures and restarts. Transient errors (DNS blips, timeouts, HTTP 404/502/503 from Tandem) do not crash tconnectsync. It retries with a growing backoff — 30s, 60s, 120s, 240s, then holding at AUTOUPDATE_DEFAULT_SLEEP_SECONDS — and resets as soon as a poll succeeds. Staying in-process matters: an exit discards the cached credentials, so a restart loop means a fresh login on every attempt, which risks tripping Tandem’s rate limiting.

Only once the API has been failing continuously for AUTOUPDATE_API_FAILURE_MINUTES does tconnectsync give up and exit, so that a genuine outage surfaces (roughly one restart per hour) instead of disappearing into an endless quiet retry. Invalid credentials are never retried — they exit immediately, since retrying cannot help.

Running with Cron

If you choose not to run tconnectsync with --auto-update continuously, you can instead run it at a periodic interval (i.e. every 15 minutes) by just invoking tconnectsync with no arguments via cron.

If using Pipenv or a virtualenv, make sure that you either prefix the call to main.py with pipenv run or source the bin/activate file within the virtualenv, so that the proper dependencies are loaded. If not using any kind of virtualenv, you can instead just install the necessary dependencies as specified inside Pipfile globally.

An system-wide example configuration in /etc/crontab which runs every 15 minutes, on the 15 minute mark:

# m         h  dom mon dow user   command
0,15,30,45  *  *   *   *   root   /path/to/tconnectsync/run.sh

An example of a user crontab crontab -e if not running system-wide, which runs every 15 minutes:

*/15 * * * * /path/to/tconnectsync/run.sh

You can use one of the same run.sh files referenced above, but remove the --auto-update flag since you are handling the functionality for running the script periodically yourself.

For Native Windows

Create a batch file ‘tconnectsync.bat’ file containing:

python "C:\Users\<USERNAME>\AppData\Local\Programs\Python\<PYTHONVERSIONDIRECTORY>\Lib\site-packages\tconnectsync\main.py" --auto-update

If python does not exist in your path, specify the full path to python.exe.

If main.py doesn’t exist in C:\Users\<USERNAME>\AppData\Local\Programs\Python\<PYTHONVERSIONDIRECTORY>\Lib\site-packages\tconnectsync\, create it to match the copy in this repository.

Use Windows Task Scheduler to run this batch file on a scheduled basis.

Tandem APIs

As of version 2.0, tconnectsync retrieves all of its data from a single Tandem API, tandemsource, which powers Tandem Source. After logging in, tconnectsync fetches the list of pumps on the account along with a stream of raw pump event data, which is decoded locally (see tconnectsync/eventparser) to extract basal, bolus, CGM, and other pump events.

Earlier versions of tconnectsync (1.x) instead used three separate legacy t:connect APIs (controliq, android, and tconnectws2). Those APIs — and the code supporting them — were removed once t:connect was shut down in favor of Tandem Source.

I have only tested tconnectsync with a Tandem pump set in the US Eastern timezone. Tandem’s (to us, undocumented) APIs are a bit loose with timezones, so please let me know if you notice any timezone-related bugs.

Backfilling t:connect Data

To backfill existing t:connect data in to Nightscout, you can use the --start-date and --end-date options. For example, the following will upload all t:connect data between January 1st and March 1st, 2020 to Nightscout:

python3 main.py --start-date 2020-01-01 --end-date 2020-03-01

In order to bulk-import a lot of data, you may need to use shorter intervals, and invoke tconnectsync multiple times. Tandem’s API endpoints occasionally return invalid data if you request too large of a data window which causes tconnectsync to error out mid-way through.

One oddity when backfilling data is that the Control:IQ specific API endpoints return errors if they are queried before you updated your pump to utilize Control:IQ. This is partially worked around in tconnectsync’s code, but you might need to update the logic if you did not switch to a Control:IQ enabled pump immediately after launch.

Tandem Source API Testing

To test Tandem Source API endpoints in a Python shell, you can do something like the following:

import tconnectsync
tconnectsync.util.cli.enable_logging()
api = tconnectsync.util.cli.get_api()
# Make API calls, e.g.
pumps = api.tandemsource.pump_event_metadata()