Add to Agent Context

A VS Code extension that sends the selected content directly to agent extensions, or simply copies a reference to that selection to the clipboard. See How selections are modelled for more details about what gets sent or copied when you have selections in an open editor or the file explorer.

See Demo for a demo video.

If you compile the extension directly from main, check out CHANGELOG.md for unreleased changes. Those are not documented in the README.

Installation

The extension is published on the Visual Studio Marketplace. In VS Code, open the Extensions view (Ctrl+Shift+X), search for Add to Agent Context or ozoniuss.add-to-agent-context, and click Install. Or install it from the command line:

code --install-extension ozoniuss.add-to-agent-context

You can also install it from a .vsix file:

1. Download the .vsix file from the latest release.

2. Install it from the command line:

   code --install-extension add-to-agent-context-<version>.vsix
   

   Or in VS Code, open the Command Palette (Ctrl+Shift+P), run Extensions: Install from VSIX... and pick the downloaded file.

Usage

The idea is similar to Cursor's Ctrl+L: select some code and send it straight to an agent's context, or copy a path:lines reference to paste anywhere. The latter is particularly useful if e.g. you prefer working with agents in the terminal.

In an editor:

• To send the selection to the agent you last sent to, press Ctrl+' (Cmd+' on macOS). If there is no last agent yet, it opens the picker instead. (addToAgentContext.sendSelectionToLastAgent)
• To choose which agent to send the selection to, or to copy a path:lines reference to the clipboard, press Ctrl+Shift+' (Cmd+Shift+' on macOS) and pick from the list. (addToAgentContext.sendSelectionToAgent)
• To do either with the mouse, select text by dragging. A popup appears next to the cursor with an Add to agent button for each available agent, in the order they appear in addToAgentContext.agents, and a Copy to clipboard button.

With nothing selected in the editor, the whole file is sent or copied. See Selections in the open editor for what gets sent when you select part of a line, several ranges, and so on.

In the explorer, with one or more files or folders selected:

• To send them to the agent you last sent to, press Ctrl+' (Cmd+' on macOS). If there is no last agent yet, or it can't receive files and folders, it opens the picker instead. (addToAgentContext.sendExplorerSelectionToLastAgent)
• To choose which agent to send them to, or to copy their paths to the clipboard, press Ctrl+Shift+' (Cmd+Shift+' on macOS) and pick from the list. Only agents that can receive files and folders are listed. (addToAgentContext.sendExplorerSelectionToAgent)

See Selections in the file explorer for which items are used when the keyboard cursor isn't on the selected ones.

If you just want to focus on the chat of the agent you last sent to, run Add to Agent Context: Open Last Agent Chat in Sidebar (addToAgentContext.openLastChatInSidebar). If you haven't sent to an agent yet, it asks which one to open. To choose the agent instead, run Add to Agent Context: Open Agent Chat in Sidebar... (addToAgentContext.openChatInSidebar).

The commands above were only tested when agents are opened in the sidebar.

Note that not all agents have a command that accepts a file URI. In particular, Claude Code can only mention the file open in the active editor, so by default it can't be sent files or folders from the explorer. I opened anthropics/claude-code#97535 asking for a command that adds a file or folder to the chat, like Codex's chatgpt.addFileToThread. In the meantime, there is an experimental workaround, off by default: set pasteExplorerPathsDirectly on the agent, and the extension pastes the paths into the agent's chat instead. For Claude Code, add this to settings.json:

"addToAgentContext.agents": {
    "claude": { "pasteExplorerPathsDirectly": true }
}

How the last agent is detected and known limitations

The last agent is simply the last one the extension sent to in this workspace. Any action that chose an agent, whether to send selections to it or to open its chat, will mark it as the last agent.

Switching to another agent's panel and working in it manually will not turn it into the last agent. This is mainly because VS Code does not have a reliable way to determine which panel of an extension was opened / focused last (or at least I haven't found one).

There are ways to work around this. For example, if you always keep your agents in the secondary side bar you can overwrite the keybindings to something like this, which is what I use (you could use cmd+' instead of ctrl+' on macOS):

    {
        "key": "ctrl+'",
        "command": "addToAgentContext.sendSelectionToLastAgent",
        "args": "claude",
        "when": "editorTextFocus && activeAuxiliary == workbench.view.extension.claude-sidebar-secondary"
    },
    {
        "key": "ctrl+'",
        "command": "addToAgentContext.sendSelectionToLastAgent",
        "args": "codex",
        "when": "editorTextFocus && activeAuxiliary == workbench.view.extension.codexSecondaryViewContainer"
    },
    {
        "key": "ctrl+'",
        "command": "addToAgentContext.sendExplorerSelectionToLastAgent",
        "args": "claude",
        "when": "filesExplorerFocus && !inputFocus && activeAuxiliary == workbench.view.extension.claude-sidebar-secondary"
    },
    {
        "key": "ctrl+'",
        "command": "addToAgentContext.sendExplorerSelectionToLastAgent",
        "args": "codex",
        "when": "filesExplorerFocus && !inputFocus && activeAuxiliary == workbench.view.extension.codexSecondaryViewContainer"
    },
    {
        "key": "ctrl+i",
        "command": "addToAgentContext.openLastChatInSidebar",
        "args": "claude",
        "when": "activeAuxiliary == workbench.view.extension.claude-sidebar-secondary"
    },
    {
        "key": "ctrl+i",
        "command": "addToAgentContext.openLastChatInSidebar",
        "args": "codex",
        "when": "activeAuxiliary == workbench.view.extension.codexSecondaryViewContainer"
    },

The first two entries apply in an editor, and the next two do the same in the explorer. If the agent whose panel is open can't receive files and folders, Ctrl+' in the explorer opens the picker instead. (e.g. Claude Code without pasteExplorerPathsDirectly)

Default agents

An agent is still listed in the picker when its extension isn't installed, but it is marked as unavailable.

Customizing agents

Agents are configured in settings.json under addToAgentContext.agents:

"addToAgentContext.agents": {
    // add a new agent
    "my-agent": {
        "label": "My Agent",
        "extensionId": "someone.my-agent",
        "command": "myAgent.addSelection",
        "fileCommand": "myAgent.addFile",
        "openChatInSidebarCommand": "myAgent.openSidebar"
    },
    // change one field of a built-in agent, leaving the other ones set to default
    "claude": { "label": "Claude" },
    // remove a built-in agent
    "codex": null
}

Default keybindings

The extension comes with these default keybindings.

On Windows and Linux:

{
    "key": "ctrl+'",
    "command": "addToAgentContext.sendSelectionToLastAgent",
    "when": "editorTextFocus"
},
{
    "key": "ctrl+shift+'",
    "command": "addToAgentContext.sendSelectionToAgent",
    "when": "editorTextFocus"
},
{
    "key": "ctrl+'",
    "command": "addToAgentContext.sendExplorerSelectionToLastAgent",
    "when": "filesExplorerFocus && !inputFocus"
},
{
    "key": "ctrl+shift+'",
    "command": "addToAgentContext.sendExplorerSelectionToAgent",
    "when": "filesExplorerFocus && !inputFocus"
}

On macOS:

{
    "key": "cmd+'",
    "command": "addToAgentContext.sendSelectionToLastAgent",
    "when": "editorTextFocus"
},
{
    "key": "cmd+shift+'",
    "command": "addToAgentContext.sendSelectionToAgent",
    "when": "editorTextFocus"
},
{
    "key": "cmd+'",
    "command": "addToAgentContext.sendExplorerSelectionToLastAgent",
    "when": "filesExplorerFocus && !inputFocus"
},
{
    "key": "cmd+shift+'",
    "command": "addToAgentContext.sendExplorerSelectionToAgent",
    "when": "filesExplorerFocus && !inputFocus"
}

Suggested additional keybindings

{
    "key": "ctrl+i",
    "command": "addToAgentContext.openLastChatInSidebar"
},
{
    "key": "ctrl+shift+i",
    "command": "addToAgentContext.openChatInSidebar"
}

Demo

Unfortunately my Fedora screen recorder does not show the mouse pointer for whatever reason. Still, I hope it's clear enough what the mouse does in each videos to understand how the extension works.

Use with keyboard shortcuts:

https://github.com/user-attachments/assets/239e6b06-a1f4-4708-ada0-205dfe9552ba

Use with mouse:

https://github.com/user-attachments/assets/389899de-4577-46f1-9c24-c3c9f1a6df84

How selections are modelled

The extension defines "selection" slightly differently from how VSCode defines an editor selection. Its meaning depends on whether you want to add code snippets from an open editor or from the file explorer.

Selections in the open editor

In this case, a selection will be represented as a file path, followed by line references at the end of the path.

The smallest unit of an editor selection is a line reference. Every VSCode selection in the editor is turned into the range of lines it covers, and those ranges are what gets copied or sent to an agent. Here are some examples:

Note that the order in which you created selections doesn't matter. The line number references at the end will always be written in ascending order.

There are various ways to create selections, especially with keyboard shortcuts. For a simple way to test how this works, you can make multiple selections by holding alt and making selections with the mouse.

Selections in the file explorer

In this case, a selection will be represented as one or more absolute paths of files or folders, without any line references.

The smallest unit of an explorer selection is a file or folder. VSCode tracks two things in the explorer: the selected items, shown with a filled highlight, and the focused item, shown with an outline (this typically appears when moving with the keyboard through the explorer content). The extension follows the same rule as VSCode's built-in Copy Path to decide which of them it uses. Here are some examples:

The extension does not items focused when hovering with the mouse.

Note that with a single selected item, moving the keyboard cursor away from it makes the extension use the focused item instead. With two or more selected items, the selection is always used, wherever the keyboard cursor is. To be honest, I find this behavior weird. See below for the two cases:

One item selected	Two items selected

There are various ways to select multiple items. For a simple way to test how this works, you can hold ctrl (cmd on macOS) and click items with the mouse, or hold shift and move with the arrow keys to select a range.

Troubleshooting and known issues

Code context isn't sent to Claude Code or Codex (applies to secondary side bar)

There may be a bug with how the widget is dispalyed on the sidebar. Try resetting the location of the agent's chat.

Code context isn't sent to Codex extension

The command "Codex: Add to Codex Thread" does not seem to work for some files (e.g. VS Code's keybindings.json file). It's not clear yet for which kind of files it doesn't work. If you can't send snippets to Codex, also check if the problem is with the extension's native command.

Contributing

See CONTRIBUTING.md for how to run the extension locally and how to submit changes.

Related issues

• https://github.com/microsoft/vscode/issues/339786 and https://github.com/microsoft/vscode/issues/316820 for being able to read from file explorer via an API.