Agent Platform 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, unless otherwise noted.

For some features, you can select a different model, which persists until you change it.

Default models

This table lists the default model for each feature in the Agent Platform.

Supported models

This table lists the models you can select for features in the Agent Platform.

Model availability can vary by subscription and trial status. For information about model availability during trials, see GitLab Duo Agent Platform trials.

Select a model for a feature

You can select a model to be the default 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.

Select a model for Agentic Chat

To select a model for Agentic Chat:

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. Go to the GitLab Duo Agentic Chat section.

5. From the Default model dropdown list, select a model. This model is pinned by default and cannot be changed by users unless you selected the GitLab default model. In that case, all GitLab-managed models are available to users.

6. Optional. To restrict Agentic Chat to specific models:

   1. Under the Default model dropdown list, select Configure.

   2. In the Available models: Agentic Chat dialog, select the Restrict to specific models checkbox.

   3. Select the models you want Agentic Chat to use. To select every model, select the Select all models checkbox. To clear all selected models, select Clear all models.

      The default model is always available to users and cannot be cleared. To save your changes, you must select at least one model in addition to the default model.

   4. Select Save.

   To restrict Agentic Chat to specific models, you must select a GitLab-managed model as the default model.

The restriction also applies to external agents that use GitLab-managed credentials. It also applies to third-party tools, such as OpenCode, that use a GitLab AI Gateway token. If one of these agents or tools requests a model that is not in the list, the request fails with an HTTP 403 error. Add the models that these agents use to the list. Some agents use more than one model. For example, Claude Code also uses a smaller model for background tasks.

Select a model for other agentic features

To select a model for other agentic features:

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 under GitLab Duo Agent Platform.
5. Select a model from the dropdown list to set as the default model.
6. 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.
7. Optional. To switch all features in a section back to their default models, select Reset to default.

To specify a model for the GitLab Duo CLI, see select a model.

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 without notifying the user to maintain optimal performance and reliability.

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.

Frontier models are not available during a trial

If you are using a GitLab Duo Agent Platform trial, you cannot use some frontier models because they are not included in trials.

To resolve this, either:

• Buy GitLab Credits.
• Select another available model.

For more information, see GitLab Duo Agent Platform trials.

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.

Model selection for Agentic Chat in IDEs does not work

When selecting a model for Agentic Chat in your IDE, you might find that model selection does not work.

To resolve this:

1. Check that the connection type for your IDE is set to WebSocket.
2. Ask your network administrator to make sure WebSocket traffic to your GitLab instance is allowed.