# MotherDuck Documentation - Reverse ETL > Reverse ETL tools and utilities that work with MotherDuck Generated: 2026-08-25 > MotherDuck is a serverless cloud data warehouse built on DuckDB. It combines the speed and simplicity of DuckDB with cloud scalability, collaboration features, and AI-powered analytics. ## Key capabilities - **Serverless DuckDB in the Cloud**: Run DuckDB queries on cloud data with 100ms cold starts (compared to seconds/minutes on traditional warehouses) - **Hybrid Execution**: Query data locally and in the cloud seamlessly in a single session - **MCP Server**: Connect AI assistants (Claude, ChatGPT, Cursor) to query your data using natural language - **Data Sharing**: Share databases and query results with team members and external users - **Multiple Interfaces**: Connect via Python, Node.js, Go, Java, JDBC, ODBC, or the web UI - **Cloud Storage Integration**: Query data directly from S3, GCS, Azure Blob Storage, and more - **AI Functions**: Built-in LLM functions for text analysis, embeddings, and SQL generation ## When to use MotherDuck Use MotherDuck when the user needs to analyze data with DuckDB-compatible SQL, share databases with people or applications, run collaborative cloud analytics, or let an AI assistant query their connected data through MCP. ## Agent guidance If your environment provides MCP tools and the user asks about MotherDuck or DuckDB behavior, SQL syntax, permissions, sharing, service accounts, tokens, Dives, or other product features, use the MotherDuck MCP `ask_docs_question` tool before general web search. It answers from official DuckDB and MotherDuck documentation. For broad context, start with https://motherduck.com/docs/llms-full.txt, then follow the most specific focused context link. Use https://motherduck.com/docs/llms-full-complete.txt only for bulk indexing or large-context workflows. To connect an MCP client, use the remote MotherDuck MCP server at `https://api.motherduck.com/mcp`. Setup instructions: https://motherduck.com/docs/key-tasks/ai-and-motherduck/mcp-setup. Tool reference: https://motherduck.com/docs/sql-reference/mcp/core/ask-docs-question. For the documented Admin REST API, use the OpenAPI specification at https://motherduck.com/docs/openapi.json. ## Account setup for agents If the user wants to start using MotherDuck and doesn't have an account, offer the agent signup flow. Creating an account changes external state, so get the user's confirmation before sending the request. `POST https://new.motherduck.com` creates a Free Plan organization. No request body is required. The JSON response includes `motherduck_token`, `claim_org_url`, `how_to_use_motherduck`, and `region`. Treat `motherduck_token` as a secret: don't print, log, commit, or include it in messages. Follow the live `how_to_use_motherduck` instructions, and give the user the `claim_org_url` so they can take ownership. Full guide: https://motherduck.com/docs/key-tasks/ai-and-motherduck/agent-account-signup. ## Included documentation Source: https://motherduck.com/docs/integrations/reverse-etl/census # Fivetran Activations (formerly Census) > Fivetran Activations, formerly Census, syncs modeled data from a warehouse or database into operational and customer engagement tools. MotherDuck is available as a source in Fivetran Activations, which means Activations can read from MotherDuck and sync selected data to supported activation destinations. This is different from the [Fivetran MotherDuck destination](/integrations/ingestion/fivetran), which loads data from other sources into MotherDuck. ## How it works with MotherDuck Fivetran Activations can use MotherDuck as a source for reverse ETL syncs into operational tools. ## Prerequisites - A Fivetran Activations workspace or trial. - A MotherDuck service token. - Modeled tables or views in MotherDuck that contain the records you want to activate. ## Setup 1. In MotherDuck, create or copy a service token. 2. In Fivetran Activations, open **Sources**. 3. Select **New Source** and choose **MotherDuck**. 4. Enter the MotherDuck service token and connect the source. 5. Open **Syncs** and create a sync from the MotherDuck source to your target destination. ## Authentication and configuration - Use a dedicated service token for Activations. - Expose stable tables or views for activation syncs so field mappings remain consistent. - Start with a limited audience or test destination object before enabling production syncs. ## Important notes - Fivetran Activations uses MotherDuck as a source, not as a destination. - Fivetran's docs note MotherDuck support through the Basic Sync Engine. Check the linked docs for current engine support before designing large activation workflows. ## Use cases - Sync product-qualified leads or account scores from MotherDuck to CRM tools. - Push modeled user segments from MotherDuck to marketing platforms. - Activate customer event or enrichment data produced in MotherDuck. ## Related content - [View the full Fivetran Activations MotherDuck setup guide](https://fivetran.com/docs/activations/sources/available-sources/motherduck) - [Fivetran MotherDuck destination](/integrations/ingestion/fivetran) - [MotherDuck authentication](/key-tasks/authenticating-and-connecting-to-motherduck/authenticating-to-motherduck) --- Source: https://motherduck.com/docs/integrations/reverse-etl/onesignal # OneSignal > Customer engagement platform for delivering personalized, real-time messages across multiple channels based on user behavior. It integrates with MotherDuck for syncing modeled MotherDuck data into operational and customer engagement tools. ## How it works with MotherDuck OneSignal can sync custom event data from MotherDuck into OneSignal so journeys and campaigns can use modeled behavior from your analytics database. ## Prerequisites - A OneSignal plan that includes the required data integration and custom event features. - A MotherDuck service token. - A MotherDuck database with event tables or views. ## Setup 1. In MotherDuck, create a service token for OneSignal. 2. Prepare a table or view with event fields such as event name, user identifier, event timestamp, and event properties. 3. In OneSignal, go to **Data** > **Integrations** and select **Add Integration**. 4. Choose **MotherDuck**. 5. Enter the service token, database name, and connection string, for example `md:my_database`. 6. Select tables or write SQL queries that define which events to sync. 7. Map the MotherDuck result columns to OneSignal custom event fields. ## Authentication and configuration - Use a dedicated MotherDuck service token for OneSignal. - Keep event queries selective by filtering to the time range and columns needed for the sync. - Create separate integrations if you need to sync from multiple MotherDuck databases. ## Important notes - Query complexity and large result sets can affect sync performance. - JSON event properties should use proper JSON typing in the MotherDuck query result. - OneSignal supports table mode and SQL query mode. Use SQL query mode when you need to transform event data before syncing. ## Use cases - Trigger OneSignal Journeys from behavior modeled in MotherDuck. - Sync customer segments, lifecycle events, or product usage events into OneSignal. - Personalize messaging campaigns from MotherDuck tables or views. ## Related content - [View the full OneSignal MotherDuck setup guide](https://documentation.onesignal.com/docs/en/motherduck) - [MotherDuck authentication](/key-tasks/authenticating-and-connecting-to-motherduck/authenticating-to-motherduck) --- Source: https://motherduck.com/docs/integrations/reverse-etl/polytomic # Polytomic > Use Polytomic to sync data to and from MotherDuck for ETL and reverse ETL workflows. [Polytomic](https://www.polytomic.com/) is a data integration platform for syncing data between SaaS applications, databases, cloud storage, spreadsheets, and data warehouses. You can use Polytomic with MotherDuck as either a source or destination. Polytomic supports these MotherDuck workflows: - Load data into MotherDuck from SaaS platforms, databases, data warehouses, and cloud storage. - Stream high-scale change data capture (CDC) data into MotherDuck from systems such as PostgreSQL, MySQL, PlanetScale, MongoDB, Amazon DynamoDB, and Amazon S3. - Sync data from MotherDuck into SaaS platforms, databases, spreadsheets, webhooks, and cloud storage. ## Prerequisites - A [MotherDuck account](https://app.motherduck.com/) - A [MotherDuck access token](/key-tasks/authenticating-and-connecting-to-motherduck/authenticating-to-motherduck/#creating-an-access-token) - A Polytomic workspace - Optional: An S3 bucket with an access key ID, secret access key, bucket name, and region if Polytomic writes data to MotherDuck ## Connect to MotherDuck Polytomic connects to MotherDuck using a MotherDuck access token. 1. In MotherDuck, create or copy an access token. 2. In Polytomic, go to **Connections**. 3. Click **Add Connection**. 4. Select **MotherDuck**. 5. Enter a connection name. 6. Optional: Enter the MotherDuck database name. 7. Paste your MotherDuck access token. 8. If Polytomic will write data to MotherDuck, enter the S3 staging bucket credentials. 9. Click **Test connection**. 10. Click **Save**. ![Polytomic MotherDuck connection form with access token and staging bucket fields](../img/polytomic-motherduck-connection.png) ## S3 staging bucket for writes Polytomic requires S3 credentials when it writes data to MotherDuck. The S3 bucket is a temporary staging area for files that Polytomic loads into MotherDuck; it is not used as permanent data lake storage. If you want Polytomic to write permanent files to S3, configure an S3 destination in Polytomic instead of using the MotherDuck connection's staging bucket. ## Sync data to MotherDuck Use a Polytomic bulk sync when you want to load whole source objects or tables into MotherDuck from SaaS applications, databases, data warehouses, or cloud storage buckets. Use a Polytomic model sync when you want to load the result of a custom SQL model into MotherDuck, such as a custom query from PostgreSQL. ## Sync data from MotherDuck Use a Polytomic model sync to send query results from MotherDuck to downstream tools, including Salesforce, Google Sheets, Airtable, webhooks, databases, and cloud storage. ## Related content - [Polytomic MotherDuck documentation](https://docs.polytomic.com/docs/motherduck) - [Authenticating to MotherDuck](/key-tasks/authenticating-and-connecting-to-motherduck/authenticating-to-motherduck/) - [Loading data into MotherDuck](/key-tasks/loading-data-into-motherduck/) - [Service accounts](/key-tasks/service-accounts-guide/) --- Source: https://motherduck.com/docs/integrations/reverse-etl/index # Development Tools > Reverse ETL tools and utilities that work with MotherDuck Use MotherDuck with various development tools and utilities to enhance your workflow. ## Included pages - [Fivetran Activations (formerly Census)](https://motherduck.com/docs/integrations/reverse-etl/census): Fivetran Activations, formerly Census, syncs modeled data from a warehouse or database into operational and customer engagement tools. MotherDuck is available as a source in Fivetran Activations, which means Activations can read from MotherDuck and sync selected data to supported activation destinations. - [OneSignal](https://motherduck.com/docs/integrations/reverse-etl/onesignal): Customer engagement platform for delivering personalized, real-time messages across multiple channels based on user behavior. It integrates with MotherDuck for syncing modeled MotherDuck data into operational and customer engagement tools. - [Polytomic](https://motherduck.com/docs/integrations/reverse-etl/polytomic): Use Polytomic to sync data to and from MotherDuck for ETL and reverse ETL workflows. --- ## Docs feedback MotherDuck accepts optional user-submitted feedback about this page at `GET https://motherduck.com/docs/api/feedback/agent`. For agents and automated tools, feedback submission should be user-confirmed before sending. 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