OpenCode Diff

⚠️ Beta — this extension has been largely vibe coded using opencode itself: it works, but it is still experimental and may contain bugs. Test it on scratch projects before using it on critical work, and report any issues you run into.

Why this extension exists

To bring opencode into the Copilot workflow of VS Code: ask for a change in the chat, watch the assistant work, then review every change as a diff and decide to accept or reject it before it touches your code.

The core of the extension is the diff: instead of blindly applying what the assistant proposes, every modified file is presented in a review view where you control precisely what lands in your codebase — segment by segment, file by file.

Documentation

• Configuration — every setting and command.
• Model compatibility — how a model is recognized by opencode and how the fallback works.

More detailed documentation will progressively be added to the docs/ directory.

Overview

OpenCode Diff connects the opencode assistant to VS Code:

• Native chat — use the @opencode participant in the VS Code Chat view. The response, reasoning and tool calls (edit, bash, webfetch…) are streamed live into the conversation.
• Immediate diff — modified files are detected while the run is in progress and shown in the diff editor, with inline markers (additions/deletions) on the file.
• Controlled review — the Change Review view lists every modified file. Accept or reject each segment individually, each file, or all of them at once. Code is only actually applied when accepted.
• Built-in rollback — a snapshot of each file is kept before the run: reject a change (or cancel a run) to restore the original state of the file.
• Plan mode — ask for a plan (read-only plan mode): opencode proposes changes without applying them. An Implement with opencode button then re-runs the same opencode session in build mode, keeping the conversation context.
• Questions and permissions in the chat — opencode's questions and permission requests appear in the conversation and are answered with buttons, without ever leaving VS Code.
• opencode models — pick the model among the ones configured in opencode directly from the picker at the top of the chat.

Usage

Prerequisites

• VS Code 1.127 or newer.
• The opencode binary installed and reachable (found via PATH, ~/.opencode/bin/opencode, or the usual Homebrew paths):

  npm i -g opencode-ai        # or
  brew install sst/tap/opencode
  

• A model configured in opencode (see the opencode documentation).

Installation

1. Open the Extensions view (Ctrl/Cmd + Shift + X).
2. Install OpenCode Diff from the Marketplace (or from a .vsix file: … menu → Install from VSIX).
3. Reload the window (Developer: Reload Window).

Run a request

1. Open a folder in VS Code (File → Open Folder).
2. Open the Chat view (Ctrl/Cmd + Shift + I).
3. Type a request prefixed with @opencode, for example:

   @opencode add a login form

4. opencode runs the request. The response and tool calls are streamed into the chat.

Plan mode

1. In the chat mode bar, select Plan (or use the mode configured in opencodeDiff.mode).
2. Ask @opencode your request: opencode proposes a plan without modifying your files.
3. To implement it, click Implement with opencode in the response: the same opencode session restarts in build mode with the plan context preserved.

Reviewing and applying changes

When a run produces changes:

1. The Change Review view (OpenCode Diff activity) lists the modified files.
2. Open a file to see the diff editor; the changed segments are marked inline.
3. Accept or reject:
   • Segment: buttons in the diff editor title bar, or the OpenCode Diff: Accept/Reject Segment command.
   • File: buttons on the item in the view, or the OpenCode Diff: Accept/Reject File command.
   • All: Accept All / Reject All / Discard Review buttons in the view title bar.
4. An accepted change is applied to the file; a rejected change restores the original snippet from the snapshot.