Windows setup for Agent Chat

Agent Chat runs in the Obsidian desktop app. On Windows, start with opencode unless you already use Claude Code or Codex.

1. Install opencode with Copilot

1. Open Settings → Copilot → Basic → Agents.
2. Open the opencode tab.
3. Select Download opencode. Copilot downloads and manages the Windows executable outside your vault.
4. When the status shows Ready, choose a Default model and set Default backend to opencode.

The managed installation does not require a PowerShell command or PATH changes.

If opencode is already installed, select I already have it. Copilot checks common Windows locations. If it cannot find your copy, open Configure, choose My own binary, then select Auto-detect or enter the absolute path to opencode.exe and select Apply.

If Copilot reports that your opencode version is unsupported, update opencode and run detection again.

2. Connect Claude Code

The Claude backend uses the Claude Code installation and account already on your computer.

1. Open Settings → Copilot → Basic → Agents → Claude and select Configure.
2. If Claude Code is installed, select Auto-detect under Claude Code binary.
3. If it is not installed, copy the current Install it command from the dialog and run it in PowerShell.
4. Return to Configure Claude and select Auto-detect again. If detection still fails, enter the absolute path to claude.exe and select Apply.
5. If the dialog shows Sign in, select it and complete the browser login.

You can also start the Claude Code login from PowerShell:

claude auth login --claudeai

Copilot uses Claude Code's credentials. Do not add an Anthropic API key to this dialog. If Copilot reports that the installed version is unsupported, update Claude Code and detect it again.

3. Connect Codex

The Codex backend needs @agentclientprotocol/codex-acp 0.0.45 or newer. The package includes a compatible Codex CLI; the older @zed-industries/codex-acp adapter is not supported.

1. Open Settings → Copilot → Basic → Agents → Codex and select Configure.
2. Copy the Install it command from the dialog and run it in PowerShell. The first command removes the unsupported Zed npm package because both packages create the same global codex-acp command; the second installs the supported adapter.

npm uninstall -g @zed-industries/codex-acp; npm install -g @agentclientprotocol/codex-acp

3. Return to Configure Codex and select Auto-detect under codex-acp adapter.
4. If detection fails, enter the expanded absolute path to the package entry, such as C:\Users\<your-user-name>\AppData\Roaming\npm\node_modules\@agentclientprotocol\codex-acp\dist\index.js, and select Apply. Replace <your-user-name> with your Windows user folder; the path field does not expand %APPDATA%.
5. Sign in through the installed adapter:

codex-acp cli login

Configure the package's dist\index.js, not codex.exe, codex-acp.cmd, or a legacy codex-acp.exe. Copilot launches the JavaScript entry point with the Node.js installation that provided npm and uses the bundled Codex CLI's login. If Node was installed while Obsidian was open, restart Obsidian before Auto-detect. Leave Environment variables empty unless you intentionally need an override.

Share Skills across agents

Open Settings → Copilot → Skills and toggle the opencode, Claude, or Codex icons for each Skill. Copilot keeps one shared copy and creates folder links into .opencode/skills/, .claude/skills/, and .agents/skills/.

Windows may block creation of these links. Enable Windows Settings → Privacy & security → For developers → Developer Mode, or run Obsidian with administrator access, then toggle the affected agent off and on in the Skills tab.

If a sync service replaces a folder link and a Skill disappears from an agent, toggle that agent off and on again to recreate the link.

Open Agent Chat

Select the Agent Chat ribbon icon or run Open Copilot Agent Chat Window from the command palette. Choose an installed agent and select Start chat.

For models, effort, permissions, Projects, and multi-agent answers, see Agent Chat.