GitLab Duo AI models

Every GitLab Duo feature uses a default model. GitLab might update default models to optimize performance. Model changes come from the GitLab AI Gateway and take effect regardless of your GitLab version.

You can select a different model for a feature, which persists until you change it.

Default models

The following table lists the default model for each GitLab Duo feature.

Supported models

The following tables list the models you can select for each feature.

Code Suggestions

GitLab Duo Non-Agentic Chat

GitLab Duo for merge requests

Other GitLab Duo features

Select a model for a feature

You can select a model for a feature in a top-level group. The model that you select applies to that feature for all child groups and projects.

To set a model for an instance on GitLab Self-Managed or GitLab Dedicated, see model selection.

Prerequisites:

• You have the Owner role for the group.
• The group that you select models for is a top-level group.
• In GitLab 18.3 or later, if you belong to multiple GitLab Duo namespaces, you must assign a default namespace.

To select a model for a feature:

1. In the top bar, select Search or go to and find your group.
2. In the left sidebar, select Settings > GitLab Duo.
3. Under Model selection, select Manage models.
4. Find the feature you want to configure and select a model from the dropdown list.
5. Optional. To apply a model to multiple features in a section, from the Bulk update dropdown list, select a model. The model applies only to the features it is compatible with.
6. Optional. To switch all features in a section back to their default models, select Reset to default.

Selecting the right model

For many use cases, starting with a faster, more cost-effective model like Claude Haiku 4.5 or GPT-5.4 Mini can be the optimal approach. For this approach:

1. Select Claude Haiku 4.5 or GPT-5.4 Mini.
2. Test your use case thoroughly.
3. Evaluate if performance meets your requirements.
4. Upgrade only if necessary for specific capability gaps.

You can use this approach for the following:

• Exploratory or high-volume tasks
• Applications with strict latency requirements
• Cost-sensitive implementations

Troubleshooting

When selecting models other than the default, you might encounter the following issues.

Model is not available

If you are using the default GitLab model for a GitLab Duo AI-native feature, GitLab might change the default model to maintain optimal performance and reliability, without notifying you.

If you have selected a specific model for a GitLab Duo AI-native feature, and that model is not available, there is no automatic fallback. The feature that uses this model is unavailable.

No default GitLab Duo namespace

When using a GitLab Duo feature with a selected model, you might get an error that indicates that you need to set a default GitLab Duo namespace.

This issue occurs when you belong to multiple GitLab Duo namespaces or work on a project locally that does not have a GitLab remote configured.

To resolve this, set a default GitLab Duo namespace.