Unable to Assign Cosmos DB Built-in Data Contributor Role to Azure Function

Question

Unable to Assign Cosmos DB Built-in Data Contributor Role to Azure Function

Sourav Kisku 0

In Azure Cosmos DB, there is difficulty in assigning the role of Cosmos DB Built-in Data Contributor to an Azure Function. The option to assign this role is not visible. What steps can be taken to resolve this issue?

Saraswathi Devadula 10,855 Reputation points Microsoft External Staff Moderator

2025-08-11T04:50:43.8666667+00:00

Hello Sourav Kisku

Just checking in to see if the below answer provided by @Marcin Policht helped.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

1 answer

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Saraswathi Devadula 10,855 Reputation points Microsoft External Staff Moderator

2025-08-11T04:50:43.8666667+00:00

Hello Sourav Kisku

Just checking in to see if the below answer provided by @Marcin Policht helped.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Answer 1

Try the following:

Enable the managed identity for the Function App

Go to your Azure Function in the portal.
Identity → System assigned → Status: On → Save.
This creates a principal in Entra ID that you can grant the Cosmos DB role to.
If you’re using a User-assigned managed identity, make sure it exists and is attached to the Function App.

Assign the role at the correct scope

Navigate to your Cosmos DB account in the Azure portal.
Access control (IAM) → Add role assignment.
In Role, search for Cosmos DB Built-in Data Contributor.
Assign access to → Managed identity → Select your Function App.

Confirm the API type supports RBAC

RBAC roles like Built-in Data Contributor are supported for SQL API, Mongo API (vCore), and certain other APIs, but not all features in all API types support it.
For unsupported APIs, you’ll need to use keys instead of RBAC.

If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

hth

Marcin

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Unable to Assign Cosmos DB Built-in Data Contributor Role to Azure Function

1 answer

Your answer