> ## Documentation Index
> Fetch the complete documentation index at: https://bedrockdynamics.studio/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Changelog

> Release history and recent changes to Substrate.

Substrate uses [semantic versioning](https://semver.org/). The changelog is updated automatically with each release via [release-please](https://github.com/googleapis/release-please). The current version is **0.1.1**, with 35 tagged releases from `v0.0.1` through `v0.4.5`.

<Note>
  Changes listed under "Latest Changes" have been merged but not yet included in a tagged release.
</Note>

## Latest Changes

### AI Assistant

* **Output styles**: Switch between concise, explanatory, and terse response modes with the `/style` command.
* **Skills**: Reusable prompt workflows (`/plan-fix`, `/explain-code`, `/review-code`) that guide the assistant through structured processes.
* **Snapshot and rollback**: Every file edit is auto-checkpointed. Each assistant message shows a Revert button for atomic multi-file undo.
* **Task management**: Create, track, and complete structured task lists with DAG dependency tracking. Tasks auto-unblock when dependencies complete.
* **MCP server integration**: Connect the assistant to external services (Linear, GitHub, or custom servers via `.substrate/mcp.json`) through the Model Context Protocol.
* **Lifecycle hooks**: Attach shell commands, prompt injections, or notifications to 14 agent lifecycle events (PostEdit, PostBash, PreCommit, etc.) with glob-based file matching.
* **Permission rules**: Hierarchical allow/deny/ask rules for tool access and file paths, with organization > workspace > user precedence.

### Simulation

* **Container flight tools**: Each PX4 + Gazebo simulation container now
  exposes a native set of flight control tools — arm, disarm, takeoff, land,
  go-to, set flight mode, return to launch, run script, and get flight state —
  available under `sim0__` prefixed names scoped to the container. Substrate
  injects a mission workflow prompt at session start with validated sequencing
  and error-handling rules.
  See [Simulation MCP Server](/substrate/reference/sim-mcp-server).
* **Automatic port management**: The proxy allocates ports for container tool
  connections automatically. No manual configuration needed, even when multiple
  containers run simultaneously.

### Scene Authoring

* **Entity inspector** with live data display, physics properties, joint configuration, sensor previews, and collision geometry overlays.
* **Transform gizmo** with translate and rotate modes, GPU-pickable axis handles, screen-space scaling (80px), and 30 Hz update throttling.
* **Model browser** with local Gazebo Fuel cache scanning, thumbnail previews, remote Fuel API search with debounced queries, and spawn-at-camera-focus for local models.
* **Context menu** on right-click in the 3D viewer: Focus, Inspect, Duplicate, Delete, and Copy Pose actions.
* **SDF material backfill** to fill missing material properties from SDF defaults, along with a proto alpha channel fix for transparent surfaces.

### Session Persistence

* **Workspace session save/restore**: panel layout, open editors, and active simulation configuration are saved on close and restored on the next launch.
* **Plot subscription persistence**: telemetry channel subscriptions and plot group assignments survive across sessions.
* **Layout preset tracking**: save and recall named panel arrangements.

### UX Improvements

* **Cross-panel hover sync**: hovering a timestamp in a telemetry plot highlights the corresponding position in the 3D viewer and other synchronized panels.
* **Startup progress indicators**: visual feedback during Docker image pulls, simulation boot, and bridge initialization.
* **Readiness toasts**: notifications when simulation subsystems (GPS, EKF, compass) transition to ready state.