Custom MCP Server on Databricks Apps

# Example - custom MCP server on Databricks Apps This example shows how to create and launch a custom agent on Databricks Apps. Please note that this example doesn't use any Databricks SDK, and is independent of the `mcp` package in the root dir of this repo. ## Prerequisites - Databricks CLI installed and configured - `uv` ## Local development - run `uv` sync: ```bash uv sync ``` - start the server locally. Changes will trigger a reload: ```bash uv run custom-server ``` This will start the server on http://localhost:8000 ## Deploying a custom MCP server on Databricks Apps There are two ways to deploy the server on Databricks Apps: using the `databricks apps` CLI or using the `databricks bundle` CLI. Depending on your preference, you can choose either method. Both approaches require first configuring Databricks authentication: ```bash export DATABRICKS_CONFIG_PROFILE=<your-profile-name> # e.g. custom-mcp-server databricks auth login --profile "$DATABRICKS_CONFIG_PROFILE" ``` ### Using `databricks apps` CLI To deploy the server using the `databricks apps` CLI, follow these steps: Create a Databricks app to host your MCP server: ```bash databricks apps create mcp-custom-server ``` Upload the source code to Databricks and deploy the app: ```bash DATABRICKS_USERNAME=$(databricks current-user me | jq -r .userName) databricks sync . "/Users/$DATABRICKS_USERNAME/my-mcp-server" databricks apps deploy mcp-custom-server --source-code-path "/Workspace/Users/$DATABRICKS_USERNAME/my-mcp-server" ``` ### Using `databricks bundle` CLI To deploy the server using the `databricks bundle` CLI, follow these steps [//]: # (TODO: would be nice to also be able to use the same uv command to auto-install dependencies and run the app) Update the `app.yaml` file in this directory to use the following command: ```yaml command: ["uvicorn", "custom_server.app:app"] ``` - In this directory, run the following command to deploy and run the MCP server on Databricks Apps: ```bash uv build --wheel databricks bundle deploy databricks bundle run custom-mcp-server ``` ## Connecting to the MCP server [//]: # (TODO: once official Databricks docs for using MCP servers in agents are live, replace this with a link) [//]: # (to that section) To connect to the MCP server, use the `Streamable HTTP` transport with the following URL: ``` https://your-app-url.usually.ends.with.databricksapps.com/mcp/ ``` For authentication, you can use the `Bearer` token from your Databricks profile. You can get the token by running the following command: ```bash databricks auth token -p <name-of-your-profile> ``` Please note that the URL should end with `/mcp/` (including the trailing slash), as this is required for the server to work correctly.