py-repl-app-mount

py-repl-app-mount

Interactive bash REPL over a Mesa repo using the Mesa Python SDK. No AI, no agent, no sandbox, just bash through an app-level virtual filesystem mount.

Connects to a Mesa repo via mesa.fs.mount() and gives you a $ prompt. You type bash commands (ls, cat, grep, find, etc.), you see output, all against files in a Mesa repo with no cloning and no local disk checkout.

Quick start

# Install uv if you don't have it
curl -LsSf https://astral.sh/uv/install.sh | sh

# Create a .env in this directory (gitignored)
cp .env.example .env

# Now populate your .env file with the required values

# Run
uv run main.py

Connecting to your-org/your-repo via Mesa...
Connected to your-org/your-repo.
Type "exit" or Ctrl+C to quit.

$ ls
README.md  src/  package.json
$ cat README.md
# My Project
...
$ exit
Bye!

How it works

1. Mesa initializes a Python SDK client for your org.
2. mesa.fs.mount() mounts the repo at the main bookmark as a virtual filesystem.
3. mesa_fs.changes.new() creates a working change from main for REPL edits.
4. mesa_fs.bash() returns a bash instance backed by the virtual filesystem.
5. After each command, the REPL callback moves the main bookmark to the working change.

Files

File	Description
main.py	Environment loading, Mesa client setup, and virtual filesystem mount
repl.py	Tiny async REPL that executes commands with bash.exec()
pyproject.toml	uv project metadata and dependencies

Environment variables

Variable	Description
MESA_ORG	Your Mesa organization slug
MESA_REPO	The repository to mount
MESA_API_KEY	Mesa API key (get one here)

Requirements

• Python >= 3.10
• uv
• Mesa account with an API key