What is GitLab Duo?
GitLab Duo is the umbrella name for the AI capabilities in GitLab. Rather than living in a separate tool, its features appear where developers already work: in code editors through extensions for Visual Studio Code, JetBrains IDEs and other editors, and in GitLab’s web interface on issues, merge requests, pipelines and vulnerability reports. Because GitLab keeps planning data, code, CI/CD results and security findings in one system, Duo can draw on that shared context when it answers a question or takes action.
The first generation of Duo, introduced in 2023, focused on assistance. It offered code suggestions that complete or generate code, a chat assistant, explanations of code and vulnerabilities, summaries of discussions, root cause analysis for failed CI/CD jobs and suggested fixes for security findings. With GitLab 18.0 in May 2025, code suggestions and chat became part of Premium and Ultimate subscriptions at no extra charge. GitLab states that it does not train generative AI models on customers’ private data.
The Duo Agent Platform, generally available since GitLab 18.8 in January 2026, moves the product toward agents. Agentic Chat can create and edit files as well as issues and merge requests; foundational agents specialize in planning, CI/CD, data analysis and security triage; and flows chain agents together for multi-step jobs such as turning an issue into a merge request or fixing a broken pipeline. Teams can publish custom agents in an AI Catalog, connect outside services through the Model Context Protocol, choose among supported language models and, on GitLab Self-Managed, use self-hosted models. Agent usage is billed through GitLab Credits.
Key features of GitLab Duo
- 01
Code Suggestions
Suggestions in supported IDEs complete the current line or generate whole functions from natural-language comments, covering widely used languages such as Python, Java, JavaScript, Go and C++.
- 02
Agentic Chat
A chat assistant in the GitLab interface and in IDEs answers questions about a project and can create or edit files, issues and merge requests using context from the repository and related work.
- 03
Foundational agents
Prebuilt agents handle specific jobs, including a Planner Agent for organizing work, a CI Expert Agent for building and debugging pipelines and a Security Analyst Agent for triaging vulnerabilities.
- 04
Flows
Flows chain agents into automated sequences, such as turning an issue into a merge request, fixing a failed CI/CD pipeline or reviewing code, and can be triggered by GitLab events such as mentions.
- 05
AI code review
Duo reviews merge requests and leaves comments on potential bugs, security problems and style issues, so human reviewers can spend more of their time on design and logic.
- 06
Vulnerability explanation and fixes
For findings from GitLab’s security scanners, Duo explains what a vulnerability means and how it could be exploited, and it can open a merge request with a proposed fix.
- 07
Model choice and self-hosting
Organizations can choose which supported large language models power agents, flows and chat, and GitLab Self-Managed customers can run approved models on their own infrastructure.
- 08
AI Catalog and MCP
An AI Catalog lets teams publish and share custom agents and flows, while Model Context Protocol support connects agents to external services and lets MCP-compatible tools reach GitLab data.
Who uses GitLab Duo?
- Developers use code suggestions and chat in their IDE to write, explain and refactor code without leaving the editor.
- Platform engineering teams use CI/CD agents and flows to diagnose failing pipelines and convert existing build configurations to GitLab CI/CD.
- Application security teams triage scanner findings with vulnerability explanations and let Duo draft merge requests that fix common issues.
- Engineering managers use the Planner Agent to break down large pieces of work, summarize issue discussions and check the status of projects.
- Regulated organizations run Duo with self-hosted models on GitLab Self-Managed so that source code and prompts stay inside their own environment.
History of GitLab Duo
GitLab introduced the GitLab Duo name in June 2023, grouping AI features it had been developing across the product, from code suggestions to vulnerability explanations. Code Suggestions became generally available in GitLab 16.7 in December 2023, and the company sold its AI assistants through per-user add-ons called Duo Pro and Duo Enterprise while it expanded chat and other features.
With GitLab 18.0 in May 2025, code suggestions and chat were included in Premium and Ultimate subscriptions. The Duo Agent Platform, previewed during 2025, reached general availability with GitLab 18.8 on January 15, 2026, alongside GitLab Credits, a usage-based pricing model for AI. Its agents and flows shifted GitLab Duo from answering developers’ questions toward carrying out multi-step tasks across planning, coding, testing and security, and the platform can also run external coding agents such as Anthropic’s Claude Code and OpenAI’s Codex CLI inside GitLab.
- 2023
GitLab introduces the GitLab Duo name for its AI features in June.
- 2023
Duo Code Suggestions becomes generally available in GitLab 16.7 in December.
- 2025
GitLab 18.0 includes Duo code suggestions and chat in Premium and Ultimate subscriptions.
- 2026
The Duo Agent Platform becomes generally available in GitLab 18.8, with usage-based GitLab Credits.
GitLab Duo pricing
Pricing modelUsage-based
Premium and Ultimate plans include monthly GitLab Credits per user for agent features; further usage, and access from the Free tier, is paid for with purchased credits.
Prices change often. Check the official GitLab Duo website for current plans.
GitLab Duo alternatives
Well-known alternativesGitHub Copilot, Cursor, Claude Code, Gemini Code Assist and Tabnine
GitLab Duo: frequently asked questions
Who makes GitLab Duo?
GitLab Duo is made by GitLab Inc., the Nasdaq-listed company behind the GitLab DevSecOps platform. GitLab introduced the Duo brand in 2023 for AI features built directly into its product, and under CEO Bill Staples the company has centered its AI strategy on the Duo Agent Platform.
What is GitLab Duo used for?
GitLab Duo is used to bring AI into software development work inside GitLab. Developers use it to generate and explain code and to review merge requests, platform teams use agents to fix CI/CD pipelines, and security teams use it to explain and remediate vulnerabilities found by GitLab’s scanners.
Is GitLab Duo free?
Not entirely. Premium and Ultimate subscriptions include a monthly allowance of GitLab Credits per user for Duo Agent Platform features, and usage beyond that allowance is paid for with additional credits. Customers on the Free tier can use agent features only by buying credits, and trials are available.
When was GitLab Duo released?
GitLab introduced GitLab Duo in June 2023, and its Code Suggestions feature became generally available in December 2023. The agent-based Duo Agent Platform reached general availability on January 15, 2026, with the GitLab 18.8 release.
Which AI models does GitLab Duo use?
GitLab Duo runs on large language models from third-party AI providers, and customers can choose among supported models for agents, flows and chat. Self-managed customers can also connect approved self-hosted models. GitLab says it does not train generative AI models on customers’ private data.
What is the GitLab Duo Agent Platform?
The GitLab Duo Agent Platform is the agent-based part of GitLab Duo, generally available since January 2026. It provides Agentic Chat, specialized agents for planning, CI/CD and security, flows that chain agents into multi-step automations, and an AI Catalog for custom agents, all using context from GitLab projects.
Sources
- GitLab Announces the General Availability of GitLab Duo Agent Platform about.gitlab.com
- GitLab Duo Agent Platform, GitLab about.gitlab.com
- GitLab Duo Agent Platform documentation docs.gitlab.com
- Meet GitLab Duo, the suite of AI capabilities powering your workflows about.gitlab.com
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