Lucy

An AI coding agent for VS Code that works with any OpenAI-compatible model provider (OpenAI, Anthropic, Google Gemini, Groq, OpenRouter, Mistral, DeepSeek, xAI, Ollama, or your own gateway). Zero external dependencies — runs on VS Code's bundled Node runtime.

Features

• Agent chat with tools: read/list/search files, write files, run commands.
• Ask mode: read-only Q&A over your codebase.
• Multiple providers: connect several OpenAI-compatible endpoints; models appear in the picker grouped by provider.
• Inline diff apply: file writes open a diff you approve/reject (no blind writes).
• Inline edit (Cmd+I / Ctrl+I): select code in the editor and describe a change; it's rewritten in place.
• Autocomplete: inline tab completions as you type (opt-in in Settings).
• Codebase indexing + @codebase: semantic search over your repo using embeddings.
• Rich @ context: Files, Folder, Code symbol, Problems (diagnostics), Git diff, Current selection, Codebase.
• Slash commands: /edit, /explain, /test, /comment, /fix, /review, /commit.
• Multiple chat tabs with history and persistence across reloads.
• MCP tool support: launch MCP servers and use their tools from the agent.
• Custom rules: auto-loads .lucy/rules.md, AGENTS.md, and other common project rule files.
• Friendly model names + auto-detect of the models your API key can use.

Setup

1. Open the Lucy view in the Activity Bar.
2. Click the gear → set your Base URL (e.g. https://api.openai.com/v1) and paste your sk-... API key → Save Key.
3. (Optional) Add more providers under Other AI providers.
4. Pick a model in the composer and start chatting.

Usage

• Chat / agent: type a request, pick Agent or Ask, press Enter.
• Context: click @ to attach files, folders, symbols, problems, git diff, selection, or a codebase search.
• Inline edit: select code → Cmd+I (Ctrl+I on Windows/Linux) → describe the change.
• Open chat: Cmd+Shift+L (Ctrl+Shift+L on Windows/Linux).
• Stop: click Stop in the composer, or run Lucy: Stop.
• Codebase search: run Lucy: Index Codebase once (command palette), then use @codebase or the agent's search_codebase tool.
• Slash commands: start a message with /test, /fix, /commit, etc.
• History: the clock icon in the view title reopens past/closed chats.

Settings

All under lucy.* (Settings UI in the gear panel):

• baseUrl, model, models, mode, providers, activeModel
• maxIterations, maxFileChars
• autoApproveReads / autoApproveWrites / autoApproveCommands
• autocomplete.enabled, autocompleteModel
• embeddingModel, indexMaxFiles
• effort, contextBudget
• rulesFile
• mcpServers — e.g. [{ "name": "fs", "command": "npx", "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path"] }]. Lucy speaks official MCP Content-Length framing.

Security

• API keys are stored in VS Code SecretStorage (OS keychain), never in plain files.
• File reads, writes, and directory listings are confined to the open workspace (including .. and absolute-path attempts). read_file also refuses .env / key files.
• File writes, shell commands, MCP tools, and subagent spawns require approval by default (toggle auto-approve at your own risk).
• Codebase indexing skips .env / key material and honors .gitignore, .cursorignore, and .lucyignore.
• @git context runs git via execFile (no shell). A short denylist blocks a few obviously destructive commands (rm -rf /, mkfs, dd if=).

License

MIT. See LICENSE.