Installing Python packages with requirements.txt

Every time your Python app or bot starts on FPS.ms, the server installs its packages with pip and then runs your code. You list the packages in a requirements.txt file, or type one or two into the Startup tab. This guide shows both ways and how to fix the errors you are most likely to see.

What happens when your server starts#

Your server runs these steps in this order on every start:

1. If the Additional Python packages field on the Startup tab is not empty, pip installs those packages.
2. If requirements.txt is in the main folder of your server, pip installs every package in it.
3. Your app starts (app.py, unless you changed the file name on the Startup tab).

These are the two pip commands the server runs:

pip install -U --prefix .local <Additional Python packages>
pip install -U --prefix .local -r requirements.txt

• No file, no error. If requirements.txt is missing, step 2 is skipped without a message. Your app then crashes when it imports a package that is not installed.
• -U means upgrade. A package without a version number is upgraded to the newest release every time the server starts. Pin your versions (see below) so a restart never changes your app.
• Packages go into .local. After the first start you will see a .local folder in Files. That is where your packages live. You do not need to touch it.

Step 1: Create requirements.txt#

You can let pip write the file for you, or write it by hand.

Let pip write it#

Open a terminal in your project's folder on your computer, in the same Python environment where your code works, and run:

pip freeze > requirements.txt

On Windows, use py -m pip freeze > requirements.txt. pip writes every package that is installed in that environment, with its exact version. If you run it outside a virtual environment, the file also lists packages your code does not use. Remove those lines before you upload it.

Write it by hand#

Put one package on each line. Use the package name from pypi.org, which is the name you would type after pip install. Here is the file Cobalt Works uses for its bot:

# Packages for cobalt-bot
discord.py==2.7.1
python-dotenv==1.2.4

The format rules:

• One package per line.
• A line that starts with # is a comment. pip ignores it.
• Do not put quotes around anything.

You choose the version with the part after the name:

Step 2: Upload it next to app.py#

1. Go to panel.fps.ms and click Manage on your server.
2. Click Files.
3. Upload requirements.txt into the main folder, the same folder as app.py. See uploading files or editing your bot code if you are not sure how.

4. To check or change the list later, click requirements.txt. Edit the lines, then click Save content.

Step 3: Restart and read the console#

1. Click Console.
2. Click Restart, or Start if your server is offline.
3. Watch the output. For each package, pip prints Collecting and Downloading lines. When it is done, it prints Successfully installed with every package and version. Then your app starts.

The first start takes longer because pip downloads everything. pip runs again on every start: pinned packages that are already installed are not downloaded again, and packages without a version are upgraded when a newer release is out.

Add a package without editing the file#

For one or two extra packages, you can use the Additional Python packages field instead of requirements.txt.

1. Click Startup. If you do not see it in the top bar, click More first.
2. Find Additional Python packages.
3. Type the package names, separated by spaces. For example: requests==2.34.2 pytz==2026.6. The field saves by itself while you type.

4. Restart your server from the Console.

Use a different file name#

The server reads the file named in the Requirements file field. It is requirements.txt by default. Change it if your file has another name or sits in a subfolder.

1. Click Startup (under More if it is not in the top bar).
2. In Requirements file, type the file name or its path from the main folder, for example requirements-bot.txt or bot/requirements.txt. Capitals matter: Requirements.txt is not the same file as requirements.txt.

3. Restart your server from the Console.

Common errors#

ModuleNotFoundError: No module named '...'#

ModuleNotFoundError: No module named 'dotenv'

Your code imports a package that was never installed. Check these three things:

1. The package is in requirements.txt, under its name from pypi.org.
2. The file is in the main folder, next to app.py.
3. The file name matches the Requirements file field exactly.

The name on pypi.org is not always the name you import:

If pip prints nothing at all before your app starts, the server did not find your file. Restart after every fix.

No matching distribution found#

ERROR: Could not find a version that satisfies the requirement discrod.py (from versions: none)
ERROR: No matching distribution found for discrod.py

pip could not find what you asked for. The text in brackets tells you why:

• (from versions: none): the package name is wrong. Here discord.py is misspelled. Search for the package on pypi.org and copy the name from there.
• A list of versions: the name is right, but the version you pinned does not exist. Pick a version from the list.
• A line above it that says Ignored the following versions that require a different python version: the package needs a newer Python than your server runs. Choose a newer Python under Runtime Version on the Startup tab, or pin an older version of the package.

Conflicting dependencies (ResolutionImpossible)#

ERROR: Cannot install -r requirements.txt (line 2) and aiohttp==3.7.0 because these package versions have conflicting dependencies.

The conflict is caused by:
    The user requested aiohttp==3.7.0
    discord-py 2.7.1 depends on aiohttp<4 and >=3.7.4

Two lines in your file ask for versions that cannot be installed together. Here discord.py 2.7.1 needs aiohttp 3.7.4 or newer, but the file pins aiohttp to 3.7.0. To fix it:

1. Read the lines under The conflict is caused by:. They name the package both sides want.
2. Remove the pin on that package (here, delete the aiohttp==3.7.0 line) or change it to a version both sides accept.
3. Restart.

Next steps#

• Store tokens and API keys in environment variables
• Deploy from GitHub
• Fix an app that will not start
• Host a Discord bot or a Telegram bot