new-modular-project

name	new-modular-project
description	Creates a new Mojo or MAX project. Use when wanting to start a new Mojo or MAX project, initializing the Pixi or UV environment to use Mojo or MAX, or when the user wants to begin a new Mojo or MAX project from scratch.

When the user wants to create a new project, first infer as many options as possible from the user's request (e.g., "new Mojo project" means type=Mojo, "called foo" means name=foo). Then use a structured multiple-choice prompt (not plain text) to gather only the remaining unspecified options in a single interaction. Do NOT ask about options the user has already provided or implied. The options to determine are:

1. Project name — ask if not specified
2. Type of project — Mojo or MAX (infer from context if the user said "Mojo project" or "MAX project")
3. Environment manager — Pixi (recommended) or uv
4. If uv: UV project type — full uv project (uv init + uv add, recommended) or quick uv environment (uv venv + uv pip install, lighter weight)
5. Channel — nightly (latest features, recommended) or stable (production)

Then follow the appropriate section below (Pixi or uv) to initialize the project and choose max or mojo as appropriate. For stable versions in the below examples, mojo will start with a 0. prefix (0.26.1.0.0.0) where max packages will not (26.1.0.0.0).

NOTE: Do not look for or use magic for Mojo or MAX projects, it is no longer supported. Pixi has fully replaced its capabilities.

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System prerequisites

Mojo requires a C linker for compilation. Install one if not already present:

OS	Command
Ubuntu/Debian	sudo apt install gcc
Fedora/RHEL	sudo dnf install gcc
macOS	xcode-select --install
Windows	Install WSL2 first (see below), then install gcc in WSL

Windows users: Mojo does not run natively on Windows. Install WSL2 (wsl --install in PowerShell), then follow the Linux instructions inside your WSL environment.

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Pixi (Recommended)

Pixi manages Python, Mojo, and other dependencies in a reproducible manner inside a controlled environment.

First, determine if pixi is installed. If it is not available for use at the command line, install it using the latest instructions found on https://pixi.prefix.dev/latest/#installation

You may need to place the pixi tool in the local shell environment after installation if it had not already been installed.

Nightly

# New project
pixi init [PROJECT] \
  -c https://conda.modular.com/max-nightly/ -c conda-forge \
  && cd [PROJECT]
pixi add [max / mojo]
pixi shell

# Existing project - add to pixi.toml channels first:
# [workspace]
# channels = ["https://conda.modular.com/max-nightly/", "conda-forge"]
pixi add [max / mojo]

Stable (v26.1.0.0.0)

# New project
pixi init [PROJECT] \
  -c https://conda.modular.com/max/ -c conda-forge \
  && cd [PROJECT]
pixi add "[max / mojo]==0.26.1.0.0.0"
pixi shell

# Existing project
pixi add "[max / mojo]==0.26.1.0.0.0"

Python-using projects

If your project uses Python libraries with Mojo:

pixi add python
pixi add requests           # conda-forge packages
pixi add --pypi some-pkg    # PyPI-only packages

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uv

uv is a fast and very popular package manager, familiar to developers coming from a Python background. It also works well with Mojo projects.

Nightly (project)

uv init [PROJECT] && cd [PROJECT]
uv add [max / mojo] \
  --index https://whl.modular.com/nightly/simple/ \
  --prerelease allow

Stable (project)

uv init [PROJECT] && cd [PROJECT]
uv add [max / mojo] \
  --extra-index-url https://modular.gateway.scarf.sh/simple/

Nightly (quick environment)

mkdir [PROJECT] && cd [PROJECT]
uv venv
uv pip install [max / mojo] \
  --index https://whl.modular.com/nightly/simple/ \
  --prerelease allow

Stable (quick environment)

mkdir [PROJECT] && cd [PROJECT]
uv venv
uv pip install [max / mojo] \
  --extra-index-url https://modular.gateway.scarf.sh/simple/

When using uv, you can use max or mojo directly by working within the project environment:

 source .venv/bin/activate

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pip

Standard Python package manager.

Nightly

python3 -m venv .venv && source .venv/bin/activate
pip install --pre [max / mojo] \
  --index https://whl.modular.com/nightly/simple/

Stable

python3 -m venv .venv && source .venv/bin/activate
pip install [max / mojo] \
  --extra-index-url https://modular.gateway.scarf.sh/simple/

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Conda

For conda/mamba users.

Nightly

conda install -c conda-forge \
  -c https://conda.modular.com/max-nightly/ [max / mojo]

Stable (v26.1.0.0.0)

conda install -c conda-forge \
  -c https://conda.modular.com/max/ "[max / mojo]==0.26.1.0.0.0"

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Version Alignment with MAX

If using MAX with custom Mojo kernels, versions must match:

# Check alignment
uv pip show mojo | grep Version   # e.g., 0.26.2
pixi run mojo --version           # Must match major.minor (e.g., 0.26.2)

Mismatched versions cause kernel compilation failures. Always use the same channel (stable or nightly) for both.

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References

• Mojo Installation Guide
• Mojo Stable Docs
• Mojo Nightly Docs