Is custom field creation supported in Microsoft Planner via Microsoft Graph API?

Hi Arockia Jeyson

Unfortunately, Microsoft Planner does not support creating or managing custom task fields through the Microsoft Graph API. The Planner endpoints in Microsoft Graph only expose predefined properties for basic (classic) Planner plans. Custom fields, as well as other advanced capabilities (such as dependencies and resource management), are part of Planner Premium.

Moreover, at this time, Microsoft has not published any roadmap or official announcement indicating that custom field support for Planner will be added to Microsoft Graph.

If your scenario requires programmatic access to custom fields, the supported approach is to use Planner Premium with Dataverse. Planner Premium data (including custom fields) is stored in Microsoft Dataverse, and Microsoft supports accessing and managing this data through the Dataverse Web API rather than Microsoft Graph.

You can read here for more information: https://learn.microsoft.com/en-us/power-apps/developer/data-platform/webapi/overview

Hope my answer will help you, for any further concern, kindly let me know in the comment section.

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Custom field creation for Microsoft Planner tasks is not supported via the Microsoft Graph API.

The Planner Graph API currently exposes only the predefined task properties and operations such as:

• Listing plans and tasks
• Listing a user’s tasks
• Creating, updating, and deleting tasks

These are documented in the Planner tasks and plans API overview, which does not include any mechanism for defining or managing custom fields on tasks.

The available operations include, for example:

• GET /groups/{id}/planner/plans – list plans for a group
• GET /planner/plans/{id}/tasks – list tasks in a plan
• GET /me/planner/tasks – list tasks assigned to the current user
• POST /planner/tasks – create a task
• PATCH /planner/tasks/{task-id} – update a task
• DELETE /planner/tasks/{id} – delete a task

No supported workaround for true custom fields on Planner tasks via Graph is documented in the provided material. For visibility into future capabilities, the Microsoft 365 roadmap is the documented source for upcoming Planner features.

References:

• Planner tasks and plans API overview
• Microsoft Planner service description
• Frequently asked questions about Microsoft Planner