Cosine — AI Coding Agent for VS Code

Your autonomous coding agent, running locally in VS Code via WebAssembly. Ask Cosine to build features, fix bugs, refactor code, or research topics — it reads your files, runs commands, and proposes changes, all from a chat sidebar.

Features

• 💬 AI Chat Sidebar — Conversational coding assistant embedded in the VS Code sidebar with streaming responses
• ⚡ WASM-Powered Agent — Runs the full Cosine agent locally via WebAssembly — no external process or daemon required
• 📂 File Operations — Reads, writes, creates, and renames files directly in your workspace
• 🖥️ Terminal Access — Executes terminal commands in the background to build, test, and inspect your project
• 🌐 Web Search & Browser — Searches the web and browses pages to gather context for your tasks
• 🗺️ Plan Mode — Step-by-step planning before the agent makes any changes
• 🤖 Multiple AI Models — Switch between different AI models from the toolbar
• 📜 Session History — Resume previous conversations or start new ones at any time
• 📎 File Attachments — Attach source files and images to your messages for additional context
• 🔀 Diff View — Review agent-proposed edits in VS Code's native diff editor before accepting
• 🐝 Subagents — Orchestrate multiple specialized agents (explore, web research, general) in Swarm mode for complex tasks

Getting Started

Install

1. Search for Cosine in the VS Code Extensions Marketplace and click Install, or install from the command line:

   code --install-extension Cosine.cosine-vscode
   

2. Reload VS Code when prompted.

Authenticate

Cosine reads credentials from ~/.cosine/auth.json. If you don't have an account yet:

1. Open the Cosine sidebar (click the Cosine icon in the Activity Bar).
2. Follow the login flow to sign in or create an account.

Your session token is stored locally and used for AI inference requests.

Usage

1. Open the sidebar — Click the Cosine icon in the Activity Bar, or run the command Cosine: Show Chat Page from the Command Palette (Ctrl+Shift+P / Cmd+Shift+P).
2. Type a message — Describe what you want: "Add input validation to the signup form", "Why is this test failing?", or "Refactor the auth module to use middleware".
3. Review changes — The agent reads your workspace, runs commands, and proposes file edits. Review diffs in VS Code's built-in diff editor and accept or reject each change.
4. Iterate — Continue the conversation to refine the result, ask follow-up questions, or start a new session.

Requirements

• VS Code 1.105.0 or later
• Internet connection — required for AI model inference

Extension Settings

This extension contributes the following commands:

Known Issues

No known issues at this time. If you encounter a problem, please open an issue (see Feedback below).

Release Notes

See CHANGELOG.md for a full list of changes by version.

Feedback

Found a bug or have a feature request? Open an issue on the GitHub repository.

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