JetBrains Plugin User Guide

Sypha for JetBrains brings high-performance agentic AI coding into IntelliJ IDEA, WebStorm, PyCharm, and the broader JetBrains ecosystem. It integrates deeply with the IDE to support intelligent code generation, project-aware assistance, and autonomous debugging workflows.

Key Capabilities

• IDE Integration: Leverages native JetBrains indexing for stronger project awareness.
• Cross-IDE Consistency: Delivers a consistent AI-assisted experience across all JetBrains products.
• Autonomous Agents: Provides specialised modes for planning, execution, and debugging.

Installation

1. Open Settings (Ctrl+Alt+S / ⌘,).
2. Navigate to Plugins.
3. Search the Marketplace for Sypha.
4. Click Install.
5. Restart the IDE to complete setup.

Alternatively, install directly from the JetBrains Marketplace.

Login and Authentication

1. Open the Sypha tool window (View → Tool Windows → Sypha).
2. Click Login.
3. Complete the browser-based sign-in flow.
4. Confirm the redirect to link the IDE to your account.

Initial Setup

1. Open Sypha Settings via the gear icon in the Sypha tool window.
2. Select your preferred Model Provider (Sypha is recommended for the standard managed experience; Custom Provider for custom model configurations).
3. Choose a high-capability model such as Claude 4.5 Sonnet.

Modes and Usage

Switch modes using the mode dropdown or slash commands. The mode controls which tools are available and how autonomously Sypha operates.

Using Context Effectively with @

To improve precision, Sypha allows you to point directly to the files, folders, or issues that matter. Type @ in the chat input to open a context picker.

Available Targets

• @file — target a specific file, for example @FastAPIUserService.ts
• @folder — target a directory, for example @src/services
• @problems — reference current workspace issues and errors

Example Prompts

Explain @FastAPIUserService.ts
Refactor @controllers/userController
Find bugs in @entire project

Why This Matters

• Improves response accuracy.
• Reduces hallucinations and irrelevant output.
• Helps Sypha focus exactly where you need it.

Power Features

Enhance Prompt

The Enhance Prompt feature transforms vague requests into clearer, more detailed specifications. Use it when a request feels too vague or when responses are weak or incomplete.

Example:

• Before: Fix this
• After: Fix null pointer issue in @src/services/fastapi/FastAPIUserService.ts and add proper error handling

YOLO Mode

YOLO Mode enables Sypha to take action without step-by-step confirmation. It can edit multiple files and execute commands automatically.

Use with caution:

• Best used on branches where changes can be reviewed or reverted easily.
• Avoid using it on sensitive production systems without strong safeguards.

See Auto-Approving Actions for full details on enabling YOLO Mode.

Terminal Automation

Sypha can automatically run terminal commands such as tests, builds, and package installations. Command results are fed back into the assistant to validate changes or continue troubleshooting.

Examples:

Run tests and fix failures
Install missing dependencies

See Terminal Automation for full details.

Browser Mode

Browser Mode allows Sypha to fetch information from the internet. Useful for documentation lookup, API research, and searching for solutions to uncommon errors.

Headless Browser Mode

Headless Browser Mode is a more advanced web interaction capability that allows Sypha to work with page elements directly — useful for end-to-end testing, verifying UI changes, and interacting with internal tools in a browser-like workflow.

Codebase Indexing

Indexing builds a local representation of your codebase by mapping symbols and their relationships, enabling faster and more accurate contextual understanding.

How to trigger indexing:

1. In the chat interface, click the left arrow button to expand the toolbar.
2. Select the DB option to open indexing settings.
3. Configure your embedding provider and vector store.
4. Click Start Indexing to begin.

Supported Embedding Providers: Ollama (local), OpenRouter, OpenAI, Amazon Bedrock, Mistral AI, Google Gemini, Vercel AI Gateway.

Supported Vector Databases: LanceDB (local setup), Qdrant (via Docker or WSL).

See Codebase Indexing for full configuration details.

Settings and Preferences

MCP Setup

Sypha can connect to external tools through the Model Context Protocol (MCP).

1. Open the MCP tab in Settings.
2. Install integrations from the Marketplace (Apify, Atlassian, AWS, and hundreds more).
3. Add Custom MCPs for private or internal tools when needed.

See MCP Overview for full configuration details.

Recommended Workflow

1. Install the plugin and sign in through the browser flow.
2. Select your provider and model in Settings.
3. Index the workspace using the DB button.
4. Start in Chat or Strategist mode for understanding and planning.
5. Move to Developer mode for implementation.
6. Use Debugger mode when failures appear.
7. Add @ context to keep requests focused and efficient.

Best Practices

• Use @ context for precise, lower-noise prompting.
• Use Enhance Prompt when task wording is weak or incomplete.
• Avoid YOLO Mode for critical production work unless changes can be safely reviewed and reverted.
• Review terminal activity carefully when enabling command automation.

Troubleshooting

For common issues with the JetBrains plugin — including JCEF rendering, authentication via JetBrains Toolbox, and Node.js requirements — see the JetBrains Troubleshooting Guide.