Shadowfetch Linux 3.0 Launches Fireline for Safer AI Coding Agents

Shadowfetch Linux released version 3.0 "Umbra" of its Debian Testing-based distribution, introducing Fireline, a system that sandboxes autonomous coding agents like Claude Code, Codex CLI, Cursor, and Aider using Bubblewrap, with read-only OS mounts, restricted write access, optional network disable, and API key removal, plus checkpoint and rollback tools. The release also adds four first-party MCP servers and shadowfetch-ai-ignition for recommending local AI models based on VRAM, while retaining existing features like Phoenix restore points and Fireproof updates.

Shadowfetch Linux https://www.shadowfetchlinux.org/ has announced version 3.0 of its Debian Testing-based distribution built around KDE Plasma 6, combining a traditional desktop environment with local AI tooling and Btrfs-based recovery features, introducing a major new focus on running autonomous coding agents in a more controlled, reversible environment. With the new 3.0 “Umbra” release, Shadowfetch is leaning much more heavily into AI-assisted development. At the center of it is Fireline, a new system designed to keep autonomous coding agents under control by limiting what they can access, tracking the changes they make, and letting users roll those changes back if needed. The first part of that system is shadowfetch-firebreak, which can launch coding agents such as Claude Code, Codex CLI, Cursor, Aider, and similar tools inside a Bubblewrap sandbox. Inside that environment, the operating system is mounted read-only. Write access is limited to the selected project under the user’s ~/Workspaces directory. Network access can be disabled, and environment variables containing API keys or authentication tokens are removed before the agent starts. Each session additionally creates a checkpoint beforehand and records an audit entry through systemd’s journal. Complementing that is shadowfetch-checkpoint , a new tool for taking snapshots of individual workspaces and comparing their state before and after an agent session. On Btrfs systems, it can use subvolume snapshots, while other filesystems fall back to portable archives. Users can inspect a content-based diff showing what changed and, if necessary, restore the workspace to its previous state. Shadowfetch 3.0 also introduces four first-party MCP servers for the Model Context Protocol. These provide controlled interfaces for reading system information, viewing available restore points, creating and managing workspace checkpoints, and accessing files within a restricted scope. Among them is a read-only “passport” service exposing privacy-scrubbed system information, along with separate Phoenix, checkpoint, and filesystem services. Shadowfetch also provides a command for generating configuration that can be copied into compatible AI clients. Another new component, shadowfetch-ai-ignition, attempts to simplify choosing a model for local inference. Instead of showing a generic list of models, the tool checks the machine’s available VRAM and recommends models that fit the hardware. Its catalog currently focuses on openly available models like Qwen3, Devstral, and gpt-oss. Importantly, the distribution bundles no models, and downloads remain explicitly user-initiated. Existing Shadowfetch features introduced in earlier releases remain available as well. These include the Shadowfetch Guide and its private System Passport, Phoenix restore points for Btrfs installations, the Fireproof update system that simulates package changes before applying them, and the optional Buzz local-AI workspace. The distribution continues to use Calamares for installation, supports both BIOS and UEFI systems, offers LUKS2 disk encryption, and ships with a signed ISO and signed APT repository. The project also states that the distribution contains no telemetry. For additional details, see the official announcement https://www.shadowfetchlinux.org/changelog v3-0-0 . Shadowfetch Linux 3.0 “Umbra,” also carrying the Fire Edition subtitle “Backfire,” is available exclusively for 64-bit x86 systems. The distribution remains based on Debian Testing and ships with KDE Plasma 6 as its desktop environment. Image credits: Shadowfetch