Custom Agents
Custom Agents let you create specialized AI assistants tailored to specific tasks. Define custom instructions, choose which tools the agent can use, and build focused assistants for your workflows.
Overview
Unlike the built-in modes (Agent, Plan, Browser), Custom Agents are fully configurable:
| Feature | Built-in Modes | Custom Agents |
|---|---|---|
| System prompt | Fixed | You define it |
| Available tools | Predetermined | You select them |
| Visual styling | Standard colors | Choose from 11 colors |
| Purpose | General use | Your specific workflows |
Why Create Custom Agents?
Focused Assistance
Create agents specialized for code review, documentation, testing, or any specific task
Safety Guardrails
Limit tool access—create a "reviewer" that can read but not write code
Consistent Behavior
Define prompts that ensure the AI follows your team's standards
Workflow Optimization
Build agents that match how you actually work
Creating a Custom Agent
Open Agent Settings
Go to Settings → Agents tab.
Click "New Agent"
Click the New Agent button to open the creation form.
Configure your agent
Fill in the agent details:
Name — A descriptive name (e.g., "Code Reviewer", "Doc Writer")
Color — Choose from 11 colors for visual identification
System Prompt — Instructions that define the agent's behavior and expertise
Tools — Select which tools this agent can use
Save and use
Click Save Agent. Your new agent appears in the Mode Selector dropdown under "Custom Agents".
Configuring Tools
Select which capabilities your agent has access to:
File Operations
- Read Files — View file contents
- Write File — Create or overwrite files
- Edit File — Make targeted changes to files
Search & Navigation
- Scan Folder — List directory contents
- File Tree — Display project structure
- Search Files — Full-text search
- Grep Files — Regex pattern search
System
- Terminal — Execute shell commands
- MCP Tools — Access Model Context Protocol integrations
Interaction
- Ask User Question — Prompt for user input
Browser
- Browser — Full browser automation (17 sub-tools)
Less is more. Restricting tools helps agents stay focused and prevents unintended actions.
Writing Effective System Prompts
The system prompt defines your agent's personality and behavior. Here's how to write effective prompts:
Be Specific About Role
You are a senior security engineer specializing in code review. Focus on identifying vulnerabilities, insecure patterns, and potential attack vectors.
Define Expectations
Always explain your findings clearly. Provide specific line numbers and suggest concrete fixes. Prioritize issues by severity: Critical, High, Medium, Low.
Set Constraints
Do not modify any files directly. Only provide recommendations and explanations. Ask clarifying questions if the scope is unclear.
Include Domain Knowledge
Follow OWASP Top 10 guidelines. Check for SQL injection, XSS, CSRF, and authentication bypasses. Consider the principle of least privilege.
Example Agents
Code Reviewer
| Setting | Value |
|---|---|
| Name | Code Reviewer |
| Color | Red |
| Tools | Read Files, Grep Files, Search Files |
| Prompt | "You are a strict code reviewer focused on security, performance, and best practices. Analyze code for bugs, vulnerabilities, and improvement opportunities. Never modify files—only provide feedback and suggestions." |
Documentation Writer
| Setting | Value |
|---|---|
| Name | Doc Writer |
| Color | Blue |
| Tools | Read Files, Write File, Edit File, Search Files |
| Prompt | "You are a technical documentation specialist. Create clear, comprehensive documentation with examples. Follow the existing documentation style in this project. Include code examples where helpful." |
Bug Investigator
| Setting | Value |
|---|---|
| Name | Bug Hunter |
| Color | Orange |
| Tools | Read Files, Grep Files, Search Files, Terminal |
| Prompt | "You are a debugging expert. Analyze code to find root causes of bugs. Use search tools extensively to trace issues across the codebase. Provide detailed explanations of what's causing the problem and how to fix it." |
Test Writer
| Setting | Value |
|---|---|
| Name | Test Writer |
| Color | Green |
| Tools | Read Files, Write File, Edit File, Terminal |
| Prompt | "You are a testing specialist. Write comprehensive unit and integration tests. Follow the existing test patterns in this project. Ensure good coverage of edge cases and error conditions. Run tests after writing them." |
Managing Agents
Edit an Agent
- Go to Settings → Agents
- Find the agent you want to modify
- Click the Edit icon
- Make your changes
- Click Save Changes
Delete an Agent
- Go to Settings → Agents
- Find the agent to delete
- Click the Delete icon
- Confirm deletion
Temporarily Disable
Toggle the Active switch to hide an agent from the Mode Selector without deleting it.
Search Agents
Use the search bar in the Agents tab to find agents by name.
Using Custom Agents
Once created, your agents appear in the Mode Selector:
- Click the Mode Selector in the input area
- Scroll to Custom Agents section
- Click your agent to activate it
- The agent's color appears in the mode indicator
- Start chatting—the agent uses your custom prompt and tools
Best Practices
Start Narrow, Expand Later
Begin with minimal tools and add more only if needed. It's easier to add capabilities than to restrict them.
Test Your Prompts
Try your agent on various tasks to ensure the prompt produces the behavior you want.
Use Descriptive Names
Names like "Security Reviewer" or "API Doc Writer" make it clear what each agent does.
Document Your Agents
Keep notes on what each agent is for, especially if you have many.
Related
- Agent Mode — The default general-purpose mode
- Plan Mode — For strategic planning
- Browser Mode — For web automation