Pyrefly Extension for Zed

This extension adds support for Pyrefly, a static type checker for Python, to Zed.

Installation

1. Install Pyrefly

pyrefly must be installed on your system, and available in your $PATH in order to use in Zed.

You can install Pyrefly globally on your system using uv

uv tool install pyrefly

See the Pyrefly documentation for other installation methods.

2. Install the Extension

Search for pyrefly in the Zed extensions panel and click to install.

Enable

Disable pyright (or other Python language servers) and enable pyrefly in your Zed settings:

{
  "languages": {
    "Python": {
      "language_servers": ["pyrefly", "!pyright", "!pylsp"]
    },
  }
}

Configure

Configure under lsp.pyrefly.settings as required.

The "binary" setting is optional. If not set, pyrefly will be searched for in your $PATH.

{
  "lsp": {
    "pyrefly": {
      "binary": {
        "path": ".venv/bin/pyrefly",
        "arguments": ["lsp"]
      },
      "settings": {
        "python": {
          "pythonPath": ".venv/bin/python"
        },
        "pyrefly": {
          "project_includes": ["src/**/*.py", "tests/**/*.py"],
          "project_excludes": ["**/.[!/.]*", "**/*venv/**"],
          "search_path": ["src"],
          "ignore_errors_in_generated_code": true
        }
      }
    }
  }
}

Configuration Options

Pyrefly offers a variety of configuration options, which can be specified in your Zed settings or in a pyrefly.toml or pyproject.toml file in your project:

project_includes: List of glob patterns for files to type check
project_excludes: List of glob patterns for files to exclude from type checking
search_path: Roots for import resolution
python_version: Python version to use for type checking
python_platform: Platform to use for type checking
ignore_errors_in_generated_code: Whether to ignore errors in generated code

For a complete list of configuration options, see the Pyrefly documentation.

Using with Virtual Environments

For virtual environments, specify your Python interpreter in your project settings (zed: open project settings):

{
  "lsp": {
    "pyrefly": {
      "settings": {
        "python": {
          "pythonPath": ".venv/bin/python"
        },
        "pyrefly": {
          "python_interpreter": ".venv/bin/python"
        }
      }
    }
  }
}