> ## Documentation Index > Fetch the complete documentation index at: https://docs.streamnative.io/llms.txt > Use this file to discover all available pages before exploring further. # Open Catalog for Iceberg on GCP This guide describes how to prepare a Snowflake Open Catalog (Polaris) for use with StreamNative Ursa as an Iceberg catalog on Google Cloud Platform (GCP). > **Important:** Polaris does not support reading buckets from a different region. The StreamNative Ursa cluster, the GCS bucket, and the Polaris catalog must all reside in the **same region**. ## Prerequisites * A Snowflake standard account * A GCP project with permissions to create GCS buckets and IAM roles * Access to the Snowflake Open Catalog feature ## 1. Create a Snowflake Open Catalog Account The Snowflake Open Catalog console requires a dedicated **Open Catalog** account. From the standard Snowflake console, navigate to **Admin -> Accounts** and use the toggle to **Create Snowflake Open Catalog Account**.

Configure the account with: * **Cloud:** GCP * **Region:** the region in which your GCS bucket resides * **Edition:** any Account configuration

Provide an admin username and password. Account credentials

After creation, click the **Account URL** to sign in to the Open Catalog console. Account created

## 2. Create the Polaris Catalog In the Snowflake Open Catalog console, create a new catalog. Create catalog

Configure the catalog with: * **External:** disabled * **Storage provider:** GCS * **Default base location:** the GCS path used by the Ursa cluster (`gs:///`) Catalog configuration

Open the catalog details and record the **GCP\_SERVICE\_ACCOUNT** value. Polaris uses this service account to access GCS, so it must be granted permission on the bucket. Catalog GCP service account

## 3. Grant Bucket Permissions to the Polaris Service Account ### 3.1 Create a Custom IAM Role In the GCP console, navigate to **IAM & Admin -> Roles -> Create role** and add the following permissions: * `storage.buckets.get` * `storage.objects.create` * `storage.objects.delete` * `storage.objects.get` * `storage.objects.list`

### 3.2 Assign the Role to the Polaris Service Account Open the bucket, navigate to **PERMISSIONS -> View BY PRINCIPALS -> GRANT ACCESS**. Grant bucket access

Add the **GCP\_SERVICE\_ACCOUNT** from step 3, choose the role created in step 4.1, and click **SAVE**. Save access

## 4. Create a Connection (Service Principal) In the Open Catalog console, create a new connection that StreamNative Ursa will use to authenticate. Create connection

Configure with: * **Name:** any name * **Create new principal role:** enabled * **Principal Role Name:** any name Connection configuration

After creation, record the **Client ID** and **Client Secret** -- the secret cannot be retrieved later. Connection credentials

## 5. Create a Catalog Role and Grant Privileges Navigate to **Catalogs -> \[your catalog] -> Roles -> + Catalog Role** and create a role with the following privileges: * `NAMESPACE_CREATE` * `NAMESPACE_LIST` * `NAMESPACE_READ_PROPERTIES` * `NAMESPACE_WRITE_PROPERTIES` * `TABLE_LIST` * `TABLE_CREATE` * `TABLE_WRITE_DATA` * `TABLE_READ_DATA` * `TABLE_READ_PROPERTIES` * `TABLE_WRITE_PROPERTIES` Create catalog role

Click **Grant to Principals Role** and grant the catalog role to the principal role created in step 5. Grant to principal role

For background on the relationship between catalogs, catalog roles, principal roles, and principals, see the [Polaris Quick Start](https://polaris.io/#section/Quick-Start/Defining-a-Catalog). ## Catalog Information Summary When the steps above are complete, collect the following values for the StreamNative Ursa compaction service: | Value | Description | | -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `iceberg.uri` | Polaris REST endpoint (e.g., `https://..gcp.snowflakecomputing.com/polaris/api/catalog`). The format follows the URL of your Polaris console. | | `iceberg.warehouse` | The Polaris catalog name created in step 3 | | `iceberg.credential` | `:` from step 5 | | `iceberg.scope` | `PRINCIPAL_ROLE:ALL` | For the next steps, see [Configure Lakehouse Catalogs](../../../configure-lakehouse-catalogs).