OPEN-SOURCE AGENT WORKSPACE

Build with agents that can act.

Run useful AI work across the Web UI, desktop app, command line, browser tools, and durable project sessions.

Open the guideView on GitHub

Interactive launchernpx @hydraharness/harness

Web UI in scriptsnpx @hydraharness/harness web

Desktop appnpx @hydraharness/harness@latest desktop

Hydra is an open-source agent workspace for running useful AI work across the Web UI, desktop app, and command line.

Give an agent a workspace, a model, and the permissions it needs. Hydra keeps the session, tools, approvals, and extensions in one plugin-based runtime.

Start with the Web UI · Use the desktop app · Configure a model · Read the architecture

Run Hydra ​

From npm ​

Run the npm package without cloning or building this repository:

npx @hydraharness/harness

The first interactive run installs the hydra command through npm. After that, run hydra from your workspace; the installation reference covers PATH, updates, and removal.

The interactive launcher offers Web, Headless, and Desktop. Desktop opens the Electron app with its embedded browser, terminals, and workspace files; see the desktop guide. For scripts, CI, or redirected input, use npx @hydraharness/harness web or npx @hydraharness/harness --profile headless "<task>"; the Web UI starts at http://127.0.0.1:3080, and --no-open prevents the browser from opening automatically.

From source ​

git clone https://github.com/MaiHongPhong2010/Hydra-Harness.git
cd Hydra-Harness
pnpm install
pnpm run build
pnpm hydra web

To open the desktop app after building, run:

pnpm run desktop

The desktop guide covers npm installation and source builds.

For one headless task, run:

pnpm hydra --profile headless "summarize this repository"

What Hydra can do ​

Build and operate agents ​

• Run the same agent runtime through the Web UI, desktop app, CLI, ACP, JSON-RPC, or Python SDK.
• Choose a workspace, model provider, permission policy, and profile for each task.
• Start, resume, fork, query, title, and inspect durable sessions.
• Stream model responses with token usage, context management, compaction, and system-prompt assembly.

Work directly in projects ​

• Read, write, review, diff, and undo files with workspace ownership and file locking.
• Run Bash, PowerShell, subprocesses, persistent PTY terminals, background jobs, and code-runtime tasks.
• Navigate code with language servers and compose project-specific skills.
• Use plans, goals, todos, human commands, and user questions to keep long tasks understandable.

Use the browser and the web ​

• Open and control browser pages from the desktop browser integration.
• Navigate, click, type, select, scroll, upload, inspect pages, and capture screenshots.
• Search and fetch web content through the web capability.
• Keep browser actions behind host permissions and the configured interaction policy.

Keep context across work ​

• Reconstruct model-visible work from the durable session event log.
• Resume after interruptions and fork a session when a task needs a separate direction.
• Compact long conversations while preserving the active task context.
• Store workspace, settings, credentials, page memory, and spill data through their owning plugins.

Coordinate work ​

• Delegate work to subagents and collect their results in the parent session.
• Run workflows, scheduled reminders, and background jobs from the same capability system.
• Expose Hydra through the Web server, ACP automation server, JSON-RPC, TypeScript clients, and the Python SDK.
• Build repeatable profile bundles for Web, headless, and custom deployments.

Control access and execution ​

• Require approvals for sensitive actions and select reusable permission presets.
• Apply sandbox and process policies to shells, subprocesses, files, and browser actions.
• Keep credentials in the credential capability instead of browser state or prompts.
• Fail closed when configuration, capability ownership, or durable data is invalid.

Extend the runtime ​

Every product feature is a plugin. Add or replace model providers, tools, services, storage, UI modules, skills, workflows, hooks, and capability providers through Cordis composition and profile patches.

Create your first plugin · Build a tool · Configure a plugin · Package and install it

Choose a starting point ​

First task ​

1. Open Settings → Models and configure a provider.
2. Select Choose workspace and add a project directory.
3. Start a session and ask: “Summarize this repository and identify its main packages.”

Hydra is a developer preview. APIs, configuration, and stored data can change while the foundation is being built.