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2.3k 209
04 May, 2024

What is Mentat ?

Mentat is the AI tool that assists you with any coding task, right from your command line.

Unlike Copilot, Mentat coordinates edits across multiple locations and files. And unlike ChatGPT, Mentat already has the context of your project - no copy and pasting required!

Want help understanding a new codebase? Need to add a new feature? Refactor existing code? Mentat can do it!

🍿 Example Videos

Install Mentat

It is recommended you install this package in a virtualenv:

Terminal window
# Python 3.10 or higher is required
python3 -m venv .venv
source .venv/bin/activate

Note that you’ll have to have activated the virtual environment to run mentat if you install it there.

There are then 3 install methods. The first two will just let you run it:

  • PyPI: python -m pip install mentat

  • Github: python -m pip install git+https://github.com/AbanteAI/mentat.git

The third option is useful if you’d also like to modify Mentat’s code, as well as run it:

Terminal window
git clone https://github.com/AbanteAI/mentat.git
cd mentat
# install with pip in editable mode:
pip install -e .

Selecting which LLM Model to use

We highly recommend using the default model, gpt-4-1106-preview , as it performs vastly better than any other model benchmarked so far. However, if you wish to use a different model, jump here.

Add your OpenAI API Key

You’ll need to have API access to GPT-4 to run Mentat. There are a few options to provide Mentat with your OpenAI API key:

  1. Create a .env file with the line OPENAI_API_KEY=<your-api-key> in the directory you plan to run mentat in or in ~/.mentat/.env

  2. Run export OPENAI_API_KEY=<your key here> prior to running Mentat

  3. Place the previous command in your .bashrc or .zshrc to export your key on every terminal startup

Azure OpenAI

Mentat also works with the Azure OpenAI API. To use the Azure API, provide the AZURE_OPENAI_ENDPOINT ( https://<your-instance-name>.openai.azure.com/ ) and AZURE_OPENAI_KEY environment variables instead of OPENAI_API_KEY .

In addition, Mentat uses the gpt-4-1106-preview model by default. When using Azure, you will have to set the model as described in configuration.md to the name you gave your Azure model.


Due to changes in the OpenAI Python SDK, you can no longer use OPENAI_API_BASE to access the Azure API with Mentat.

Alternative Models

Mentat uses the OpenAI SDK to retrieve chat completions. This means that setting the OPENAI_API_BASE environment variable is enough to use any model that has the same response schema as OpenAI. To use models with different response schemas, we recommend setting up a litellm proxy as described here and pointing OPENAI_API_BASE to the proxy. ollama example:

# Ensure model is downloaded and ollama is being served
ollama pull llama2
ollama serve
- Listening on
# In another terminal
pip install 'litellm[proxy]'
litellm --model ollama/llama2 --api_base http://localhost:11434 --drop_params
- Uvicorn running on
# In .env

[! NOTE]

When using a litellm proxy, the model set in Mentat’s config will not effect the model being run. To change the model, rerun the litellm proxy with a different model.


Be sure to include the —drop_params argument when running the litellm proxy! Mentat uses some arguments (such as response_format) that may not be available in alternative models.

Install universal-ctags (required to use auto-context)

Installing universal ctags is helpful if you want to use the auto-context system to have Mentat find relevant parts of files for you.

See the official instructions for installing univeresal ctags for your specific operating system, however you may be able to install a compatible version with one of the following commands:


brew update && brew install universal-ctags


sudo apt update && sudo apt install universal-ctags


choco install universal-ctags

🚀 Usage

Run Mentat from within your project directory. Mentat uses git, so if your project doesn’t already have git set up, run git init . Then you can run Mentat with:

mentat <paths to files or directories>

List the files you would like Mentat to read and edit as arguments. Mentat will add each of them to context, so be careful not to exceed the GPT-4 token context limit. To add multiple files at once, you can also provide directories as arguments. When a directory is provided, Mentat will add all the contained files, except for ones ignored in your .gitignore . In addition to files and directories, you can use glob patterns to add multiple files at once.


Exclude Files

Exclude given paths, directories, or glob patterns from Mentat’s context. Takes precedence over included file paths.

Terminal window
mentat path/to/directory --exclude exclude_me.py dir1/dir2 **/*.ts

Auto Context

The Auto Context feature in Mentat uses retrieval-augmented-generation (RAG) to select relevant snippets from your codebase to include with the user query. To enable Auto Context , use the --auto-context or -a flag when running Mentat:

Terminal window
mentat --auto-context

Auto-context will add code snippets in order of relevance up to the maximum (8000 tokens by default). Adjust the maximum number of tokens added by auto-context by using the --auto-tokens flag:

Terminal window
mentat -a --auto-tokens 8000