Juggler

What is Juggler?

Juggler is an open-source, GUI-based workbench for AI coding agents, built by Julian Storer, the creator of the JUCE C++ framework and the Tracktion DAW. Instead of a scrolling terminal transcript, it represents each session as an editable, branching document: any point in a conversation can fork into a sub-thread, and every tool call, approval and raw context message stays inspectable. It runs as a native desktop app or a headless server reachable from a browser, driving Claude, OpenAI, Gemini, Ollama, OpenRouter or DeepSeek models through a swappable JavaScript plugin system.

What does Juggler do?

You point Juggler at a coding task and it opens a Miller-column workbench where the conversation with the LLM is a tree, not a log — you can navigate, duplicate, undo/redo, or branch a sub-thread from any earlier point, and inspect the raw tool calls, approvals and context JSON behind every step instead of trusting a flat transcript. Context items, LLM-loop strategies, slash commands and even the core read/write/bash tools are JavaScript plugins you can inspect, fork or replace. It ships as a single Go binary with a Wails-based desktop client (no Electron, no Node runtime) plus a headless server mode, and a session can be driven from multiple synced clients — desktop and browser, local or remote — at once via Yjs document sync. It launched on Hacker News on 2026-07-12 (Show HN, 278 points, 118 comments) and is still early: the creator himself calls it alpha-stage software that "will need to do some growing-up out in the real world," and commenters hit real early-days friction (an LLM-connection error on first run with DeepSeek, no ACP support yet for porting existing agent plugins).

Key features

• Branching session trees: Conversations are documents, not logs, any point can fork into a recursive sub-thread with its own undo/redo history.
• Full tool-call transparency: Tool calls, approvals, thread structure and the raw context JSON message are all inspectable in a Miller-column view.
• JavaScript plugin architecture: Context items, LLM-loop strategies, slash commands and the core read/write/bash tools are swappable plugins you can inspect, fork or replace.
• Model-agnostic: Drives Claude Code (CLI or SDK), OpenAI, Gemini, Ollama, OpenRouter and DeepSeek, with the provider list built to expand.
• Multi-client, local or remote: A single session syncs across any number of simultaneous clients, desktop app and browser, on one machine or over the network, via Yjs.

What are Juggler's use cases?

• Hands-on agent supervision: A developer who wants to inspect and steer every tool call an agent makes, rather than trust an opaque terminal transcript, works through Juggler’s tree view instead.
• Exploring alternate approaches: A developer branches a session at the point an agent went the wrong direction, tries a different instruction in the fork, and keeps both threads for comparison.
• Remote / long-running sessions: A developer starts a headless Juggler server on a remote machine and drives the same session from a browser client without keeping a terminal open.

What does Juggler integrate with?

• Claude Code (CLI or SDK)
• OpenAI, Gemini, Ollama, OpenRouter, DeepSeek
• JavaScript plugin API (context items, LLM strategies, slash commands, core tools)
• Yjs-synced multi-client sessions (desktop + browser)

Why use Juggler?

• Free, open-source (AGPLv3 app / Apache-2.0 extensions) with no signup, a single Go binary, no Electron, no hosted account required.
• A genuinely different session model, branching, editable trees instead of a linear transcript, that HN reviewers called a real, differentiated take on agent orchestration.
• Model-agnostic by design, so switching between Claude, GPT, Gemini, Ollama, OpenRouter or DeepSeek does not mean switching tools.
• Built by Julian Storer, a 30-year C++ toolmaker (JUCE, Tracktion, Cmajor) with a long track record of shipping developer tools that stick around.

Pros & cons

Juggler pricing

• Open sourceFree

See current pricing on juggler.studio ↗Compare Juggler alternatives →

Juggler review

Juggler is the most structurally different take on the AI-coding-agent UI to show up in this category recently: instead of a scrolling terminal log, your session is an editable, branching tree, and every tool call, approval and raw context message stays inspectable rather than hidden behind a chat bubble. That is a real, substantive difference from Cursor, Windsurf or Aider, not a cosmetic one, and it comes free, open-source and model-agnostic across Claude, GPT, Gemini, Ollama, OpenRouter and DeepSeek. The honest catch is timing: it shipped on Hacker News on 2026-07-12 and is alpha software by the creator’s own description — a launch-day tester hit an LLM-connection error immediately, there is no ACP support yet for developers coming from an existing plugin ecosystem, and the main app’s AGPLv3 license is a stronger copyleft commitment than most rivals carry. Pick Juggler if you want hands-on visibility into what your agent is doing and are willing to run early-stage software to get it; skip it for now if you need a mature, supported tool or depend on an ACP-based plugin setup.

A genuinely new idea in a crowded category, the branching session tree is real differentiation, not a reskinned terminal, but it shipped a week ago and is honestly alpha; expect rough edges.

Frequently asked questions