Modo: Open-Source AI IDE with Spec-Driven Development and Agent Hooks

Modo is an open-source AI IDE built as an alternative to tools like Kiro, Cursor, and Windsurf. It's based on the Void editor (itself a fork of VS Code) and adds structured planning workflows on top of existing AI features like chat, inline edit (Cmd+K), autocomplete, multi-provider LLM support, tool use, and MCP integration.

Spec-Driven Development

Unlike typical prompt-to-code workflows, Modo implements a structured approach: prompt → requirements → design → tasks → code. Specs are stored in .modo/specs/<name>/ as three markdown files:

• requirements.md - user stories and acceptance criteria
• design.md - architecture, components, and data models
• tasks.md - checklist of implementation steps

Create specs with Cmd+Shift+S or by picking Spec mode in the session picker. Choose between feature or bugfix workflows, then requirements-first or design-first approaches. The agent fills each document, you review, then it executes tasks sequentially, marking them as it progresses.

Task Management Features

Open any tasks.md file to see clickable "▶ Run Task" buttons inline for each pending task. A "Run All Pending Tasks" button appears at the top. Running tasks show spinners, completed ones show checkmarks. The agent marks tasks as it works: - [ ] → - [~] → - [x].

Steering Files

Markdown documents in .modo/steering/ inject project rules into every AI interaction. They support three inclusion modes:

• always - every interaction
• fileMatch - when active file matches glob pattern
• manual - referenced via / commands in chat

Supports #[[file:path]] references to link OpenAPI specs, GraphQL schemas, or other project documentation.

Agent Hooks

JSON configs in .modo/hooks/ automate actions around the agent lifecycle. Example configuration:

{
  "name": "Lint on Save",
  "version": "1.0.0",
  "when": {
    "type": "fileEdited",
    "patterns": ["**/*.ts"]
  },
  "then": {
    "type": "runCommand",
    "command": "npx eslint --fix ${filePath}"
  }
}

Supports 10 event types: fileEdited, fileCreated, fileDeleted, promptSubmit, agentStop, preToolUse, postToolUse, preTaskExecution, postTaskExecution, userTriggered. Two action types: askAgent or runCommand. Pre-tool hooks can deny execution, with circular dependency detection built in.

Additional Features

Autopilot/Supervised toggle appears as a status bar pill, switching between autonomous agent actions and paused-for-approval mode. Wired directly to auto-approve settings for edits, terminal commands, and MCP tools. Supports parallel chat sessions as tabs, each with its own thread, context, and history.

This approach is useful for developers who want more structured AI-assisted coding with persistent task tracking and project-specific rule injection.