Customize GitLab Duo Agent Platform

You can customize the Agent Platform to match your workflow, coding standards, or project requirements.

Customization options

Method AI features1 Use cases Supported in
Use custom rules to provide instructions. - GitLab Duo Chat
- Agents
- Flows, excluding Code Review Flow		 - Apply personal preferences.
- Enforce team standards.		 - GitLab UI
- Editor extensions
- GitLab Duo CLI
Create an AGENTS.md file to provide instructions. - GitLab Duo Chat
- Flows, excluding Code Review Flow		 - Account for project-specific context.
- Organize a monorepo.
- Enforce directory-specific conventions.		 - GitLab UI
- Editor extensions
- GitLab Duo CLI
- Non-GitLab AI coding tools
Create MR review instructions to ensure consistent and specific code review standards in your project. - Code Review Flow Apply:
- Language-specific review rules.
- Security standards.
- Code quality requirements.
- File-specific guidelines.		 - GitLab UI
Create Agent Skills to provide skills. - GitLab Duo Chat
- Flows, excluding Code Review Flow		 - Provide shareable skills
- Add custom slash commands		 - GitLab UI
- Editor extensions
- GitLab Duo CLI
- Non-GitLab AI coding tools
Create workspace subagents to define specialized agents. - Developer Flow - Delegate focused tasks, like reviews or research, to specialized agents. - GitLab UI
- GitLab Duo CLI

Best practices

When you customize the Agent Platform, apply the following best practices:

  • Start with minimal, clear, and simple instructions, and add more as needed. Keep the instruction file as short as possible.

  • Make sure the instructions are specific and actionable. Provide examples as needed.

  • Choose the method that matches your use case.

  • Combine multiple methods to tailor and control how GitLab Duo behaves.

  • If you use multiple methods, consider the following file structure for your project:

    Project root directory
|─ AGENTS.md                         # Applies to multiple Duo features
|- skills/<skill-name>/
   |─ SKILL.md                       # Applies to multiple Duo features
|─ .agents/agents/
   |─ <subagent-name>.md             # Workspace subagents for the Developer Flow
|─ .gitlab/duo/
   |─ chat-rules.md                  # Custom Chat-specific rules
   |─ mr-review-instructions.yaml    # Custom code review standards
   |─ ...                            # Other configuration as needed

    You can include other configuration files in the .gitlab/duo/ folder, such as custom flow definitions, or an MCP server configuration file.

  • Document your choices in comments to explain why certain instructions exist.

  • Protect customization files with Code Owners to manage changes.

  1. Support varies by where you use these features. For more information, see the documentation for each customization method. ↩︎