OpenSquirrel Agent Control Plane

---
name: opensquirrel-agent-control-plane
description: Native Rust/GPUI control plane for running multiple AI coding agents (Claude Code, Codex, Cursor, OpenCode) side by side with coordinator/worker delegation, SSH targeting, and persistent sessions.
triggers:
  - run multiple AI agents side by side
  - opensquirrel setup and configuration
  - multi-agent grid with claude and codex
  - coordinate AI coding agents with opensquirrel
  - run claude code and codex simultaneously
  - SSH remote machine targeting for agents
  - persistent agent sessions with opensquirrel
  - delegate tasks between AI coding agents
---

# OpenSquirrel Agent Control Plane

> Skill by [ara.so](https://ara.so) — Daily 2026 Skills collection.

OpenSquirrel is a native macOS application (Rust + GPUI, Metal-rendered, no Electron) that acts as a control plane for running Claude Code, Codex, Cursor, and OpenCode simultaneously. It supports automatic sub-agent delegation, remote SSH targeting, MCP server integration, and persistent multi-turn sessions.

## Installation & Build

**Prerequisites:** Rust toolchain, macOS with Metal GPU support.

```bash
git clone https://github.com/Infatoshi/OpenSquirrel
cd OpenSquirrel
cargo build --release
./target/release/opensquirrel

As a macOS .app bundle:

cargo build --release
mkdir -p dist/OpenSquirrel.app/Contents/{MacOS,Resources}
cp target/release/opensquirrel dist/OpenSquirrel.app/Contents/MacOS/OpenSquirrel
cp assets/OpenSquirrel.icns dist/OpenSquirrel.app/Contents/Resources/
open dist/OpenSquirrel.app

Note: The .app bundle does not inherit your shell PATH. If claude, npx, or other agent CLIs aren't found, run the binary directly: ./target/release/opensquirrel

Configuration

Config file lives at ~/.opensquirrel/config.toml. State (agents, transcripts, scroll positions) is persisted at ~/.opensquirrel/state.json.

Full config.toml example

[settings]
theme = "midnight"          # midnight | charcoal | gruvbox | solarized-dark | light | solarized-light | ops | monokai-pro
font_size = 14
compact_context = false

[[runtimes]]
name = "claude"
binary = "claude"           # must be on PATH when running the binary directly
mode = "persistent"         # persistent stdin (multi-turn)
permission_flags = ["--dangerously-skip-permissions"]

[[runtimes]]
name = "codex"
binary = "npx"
args = ["codex"]
mode = "oneshot"
permission_flags = ["--dangerously-bypass-approvals-and-sandbox"]

[[runtimes]]
name = "cursor"
binary = "cursor-agent"
mode = "oneshot"
permission_flags = ["--yolo"]

[[runtimes]]
name = "opencode"
binary = "opencode"
mode = "oneshot"            # auto-approved in run mode

[[models]]
runtime = "claude"
model = "claude-opus-4-5"   # coordinator/primary
alias = "opus"

[[models]]
runtime = "claude"
model = "claude-sonnet-4-5" # worker/sub-agent
alias = "sonnet"

[[mcp_servers]]
name = "playwright"
args = ["npx", "@playwright/mcp@latest"]

[[mcp_servers]]
name = "browser-use"
args = ["uvx", "browser-use-mcp"]

[[machines]]
name = "local"
host = "localhost"

[[machines]]
name = "dev-box"
host = "192.168.1.100"
user = "ubuntu"
ssh_key = "~/.ssh/id_ed25519"
tmux_session = "opensquirrel"

Supported Runtimes

Runtime	Mode	Permission bypass flag
Claude Code	Persistent stdin (multi-turn)	--dangerously-skip-permissions
Codex	One-shot per prompt	--dangerously-bypass-approvals-and-sandbox
Cursor Agent	One-shot per prompt	--yolo
OpenCode	One-shot per prompt	Auto-approved in run mode

Keybinds Reference

Key	Action
Enter	Send prompt to focused agent
Escape	Dismiss overlay (palette, setup wizard, search)
Cmd-N	New agent — opens setup wizard
Cmd-K	Command palette (themes, compact context, kill agent, views)
Cmd-F	Search across all agent transcripts
Cmd-] / Cmd-[	Next / prev pane within group
Cmd-} / Cmd-{	Next / prev group
Cmd-V	Paste clipboard into prompt
Cmd-= / Cmd--	Zoom in / out

Setup wizard navigation: Arrow keys to move, Enter to drill into directories, Backspace to go up, Tab to advance step, Shift-Tab to go back.

Architecture Overview

~7,200 lines of Rust across 3 files:
src/
  main.rs          — UI, agent lifecycle, rendering, keybinds, persistence
  lib.rs           — Line classification, markdown parsing, diff summarization, helpers
tests/
  state_tests.rs   — 30 integration tests (navigation, scrolling, themes, search, agent lifecycle)

Built on GPUI — the GPU-rendered UI framework from Zed, used as a standalone crate. Rendered via Metal on macOS.

Agent Layout Behavior

Agents auto-arrange based on count:

Agent count	Layout
1	Full screen
2	Side-by-side split
3	2+1 arrangement
4	2×2 grid
5+	Dynamic tiling

Coordinator / Worker Delegation Pattern

A primary "coordinator" agent (typically Claude Opus) can delegate focused sub-tasks to worker agents (typically Claude Sonnet). Workers return condensed results, not full transcripts.

Typical setup:

1. Cmd-N → Select runtime: claude, model: opus → this becomes your coordinator
2. Cmd-N → Select runtime: claude, model: sonnet → worker agent
3. In the coordinator pane, prompt it to delegate: "Spawn a worker to refactor the auth module and report back"

The coordinator issues structured sub-prompts; workers execute and summarize.

Remote Machine Targeting via SSH

Configure machines in config.toml, then select a machine in the setup wizard when creating a new agent. OpenSquirrel connects via SSH + tmux.

[[machines]]
name = "gpu-server"
host = "10.0.0.50"
user = "ubuntu"
ssh_key = "~/.ssh/id_ed25519"
tmux_session = "opensquirrel-agents"

The agent CLI will run inside a tmux session on the remote host. Ensure the agent binary (claude, npx codex, etc.) is installed on the remote machine and available on its PATH.

MCP Server Integration

MCP servers are passed directly as CLI args to agent runtimes. Select which MCP servers to attach per agent during the setup wizard.

[[mcp_servers]]
name = "playwright"
args = ["npx", "@playwright/mcp@latest"]

[[mcp_servers]]
name = "browser-use"
args = ["uvx", "browser-use-mcp"]

When an agent is created with Playwright attached, OpenSquirrel appends the MCP args to the agent's launch command automatically.

Persistent Sessions

Agent state survives app restarts:

• Transcripts and scroll positions stored in ~/.opensquirrel/state.json
• Pending (unsent) prompts are preserved
• Interrupted multi-turn sessions (Claude Code persistent mode) can be resumed

To manually clear state:

rm ~/.opensquirrel/state.json

Transcript Search

Cmd-F opens a search overlay that queries across all agent transcripts simultaneously. Results are highlighted inline in each pane. Press Escape to dismiss.

Themes

Available themes: midnight, charcoal, gruvbox, solarized-dark, light, solarized-light, ops, monokai-pro

Change via Cmd-K → Command Palette → "Theme: ..." or set in config.toml:

[settings]
theme = "gruvbox"

Running the Test Suite

cargo test

Tests in tests/state_tests.rs cover: pane navigation, scroll behavior, theme switching, transcript search, agent lifecycle (spawn, kill, resume).

Common Patterns

Start a 4-agent parallel session

1. cargo build --release && ./target/release/opensquirrel
2. Cmd-N → Claude (Opus) on local machine, no MCP  [coordinator]
3. Cmd-N → Claude (Sonnet) on local machine         [worker: backend]
4. Cmd-N → Codex on local machine                   [worker: frontend]
5. Cmd-N → OpenCode on local machine                [worker: tests]

Agents auto-arrange into a 2×2 grid. Focus coordinator pane and send a high-level task.

Target a remote GPU machine

1. Add machine to ~/.opensquirrel/config.toml
2. Cmd-N → select runtime → select machine: "gpu-server"
3. Agent runs inside tmux on the remote host

Attach a browser automation MCP server

1. Ensure [[mcp_servers]] entry exists in config.toml
2. Cmd-N → setup wizard → step "MCP Servers" → check "playwright"
3. Agent launched with Playwright MCP wired in

Compact context to reduce token usage

Cmd-K → "Compact Context" — summarizes current transcript in-place for the focused agent, reducing context window usage while preserving key decisions.

Troubleshooting

Agent binary not found (claude, npx, codex not on PATH)

• Run ./target/release/opensquirrel directly instead of via .app bundle
• Or set full paths in config.toml: binary = "/usr/local/bin/claude"

Remote SSH agent not connecting

• Test SSH manually: ssh -i ~/.ssh/id_ed25519 [email protected]
• Ensure tmux is installed on the remote host
• Verify agent CLI is on the remote machine's PATH

State file corruption after crash

rm ~/.opensquirrel/state.json
# OpenSquirrel will create a fresh state on next launch

Metal/GPU errors on startup

• Requires macOS with Metal support (macOS 10.14+, any Apple Silicon or Intel Mac with discrete/integrated GPU)
• OpenSquirrel does not support Linux or Windows

Build failures

rustup update stable
cargo clean
cargo build --release

Agents not receiving prompts in persistent mode

• Claude Code persistent mode uses stdin; ensure --dangerously-skip-permissions is set in config so it doesn't pause for approval prompts mid-session

Environment Variables

OpenSquirrel itself does not read API keys — those are consumed by the agent CLIs it launches. Ensure these are set in your shell environment before launching the binary:

export ANTHROPIC_API_KEY=$ANTHROPIC_API_KEY        # for Claude Code
export OPENAI_API_KEY=$OPENAI_API_KEY              # for Codex
# Cursor Agent uses its own auth; log in via cursor CLI first