Add experimental Apps MCP server #3913
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13 failing tests:
Top 30 slowest tests (at least 2 minutes):
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lennartkats-db
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Nov 16, 2025
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Mostly non-blocking comments, want to get this in ASAP, please review
experimental/apps-mcp/cmd/check.go
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Non-blocking: this overlaps with check.go in https://github.com/databricks/cli/pull/3907/files?w=1#diff-eb58ee8a5e70c59bc4f77b27698bc7405dffb45d28ca064438c8f8a8a0f57ff6
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| The server communicates via stdio using the Model Context Protocol.`, | ||
| Example: ` # Start MCP server with required warehouse | ||
| databricks experimental apps-mcp --warehouse-id abc123 |
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Non-blocking: we should apply the "default warehouse" logic from https://github.com/databricks/cli/pull/3907/files?w=1#diff-5af5f7c0874402273882f7e0c97c9bc7a0471ad92771d90ef23c415da090f09aR74 here. That same logic, discussed with the default warehouse team, is also applied in many other client-side tools. We'll get a proper API for it in the future.
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I think we should pull in the complete getting started logic from your PR
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| // Define flags | ||
| cmd.Flags().StringVar(&warehouseID, "warehouse-id", "", "Databricks SQL Warehouse ID") | ||
| cmd.Flags().BoolVar(&allowDeployment, "allow-deployment", false, "Enable deployment tools") |
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Non-blocking: I don't think we want to keep this concept. And it seems odd to default to false?
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| // JSON-RPC 2.0 error codes as defined in the specification. | ||
| const ( |
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Non-blocking note: this is good! we have an equivalent in server.go here https://github.com/databricks/cli/pull/3907/files?w=1#diff-3ee229a3a2abf9ff54e7405e515634100baecd96c94852f8985c156189a14524R49
| return t.writer.WriteEntry(entry) | ||
| } | ||
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| func (t *Tracker) RecordToolCall(toolName string, args any, result *mcpsdk.CallToolResult, err error) { |
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Non-blocking: this is something we should also have for a CLI-based approach!
experimental/apps-mcp/lib/templates/trpc/client/components.json
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Nov 17, 2025
| } | ||
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| cmd.AddCommand(aitools.New()) | ||
| cmd.AddCommand(mcp.NewMcpCmd()) |
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The aitools package should also nest a cmd package.
experimental/apps-mcp/cmd/check.go
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| databricks experimental apps-mcp check | ||
| # Check with specific profile | ||
| databricks experimental apps-mcp check --profile production`, |
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Is this a tool call or for real users?
We have databricks auth describe that does the same.
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I think this was a carry-over from rust. I'll remove it
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- github.com/databricks/databricks-sdk-go v0.90.0 (updated) - Dependencies will be fully populated when code is copied For parity-40 (Phase 2: Code Structure Migration)
Copied all library code with original structure: - Utilities (pathutil, fileutil, version, errors) - Templates (code + embedded) - Sandbox (interface + local + dagger) - Session and trajectory - Providers (databricks, io, workspace, deployment) - MCP server Import paths still reference old package. Will fix in next phase. For parity-40 (Phase 2: Code Structure Migration)
Changed all imports: - github.com/databricks/go-mcp/pkg → github.com/databricks/cli/libs/mcp - github.com/appdotbuild/go-mcp/pkg → github.com/databricks/cli/libs/mcp - github.com/databricks/go-mcp/internal → github.com/databricks/cli/internal/mcp Added MCP dependencies: - github.com/modelcontextprotocol/go-sdk v1.1.0 - github.com/zeebo/blake3 v0.2.4 - dagger.io/dagger v0.19.6 Build still fails due to missing config/logging integration. For parity-40 (Phase 2: Code Structure Migration)
Created libs/mcp/config.go with MCP configuration types. Removed dependency on pkg/config (which used Viper). Configuration will be populated from command flags in Phase 3. Updated all imports: - config.Config → mcp.Config - config.IoConfig → mcp.IoConfig - config.ValidationConfig → mcp.ValidationConfig - config.DaggerConfig → mcp.DaggerConfig Build still fails due to missing logging integration. For parity-40 (Phase 2: Code Structure Migration)
- Fixed registry.go to use context instead of logger - Fixed trajectory.go to alias mcp SDK import - Removed logger fields from provider structs - Started replacing logger calls with log package Still TODO: - Fix provider init functions - Fix mcp SDK import aliasing in all providers - Complete logger call replacements - Fix ctx variable name conflicts For parity-40 (Phase 2: Code Structure Migration)
- Aliased mcp SDK imports to avoid package conflicts (mcpsdk) - Removed logger parameters from all providers - Added context parameters for logging throughout - All providers now use libs/log package - Renamed server package correctly - Fixed trajectory tracker to use context Build succeeds: go build ./libs/mcp/... For parity-40 (Phase 2: Code Structure Migration)
This renames the command from `databricks experimental mcp` to `databricks experimental apps-mcp` to better reflect its purpose as an Apps-focused MCP server. Changes: - Rename folder: experimental/mcp → experimental/apps-mcp - Update command name: mcp → apps-mcp - Update all import paths across Go files - Update documentation and examples in README - Update acceptance test folder structure 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
Replace the custom version package in apps-mcp with the top-level build.GetInfo() to ensure version consistency across the CLI. Changes: - Remove experimental/apps-mcp/lib/version directory - Update server.go to import github.com/databricks/cli/internal/build - Use build.GetInfo().Version instead of custom version package - Update MCP server name to "databricks-apps-mcp" 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
Replaced github.com/modelcontextprotocol/go-sdk with a minimal local implementation in experimental/apps-mcp/lib/mcp/ that provides all the functionality needed for the apps-mcp command. Changes: - Created experimental/apps-mcp/lib/mcp/ package with: - types.go: Core MCP types (Implementation, Tool, Content, etc.) - protocol.go: JSON-RPC and MCP protocol types - transport.go: STDIO transport for line-delimited JSON - server.go: MCP server with tool registration and request handling - tool.go: Typed tool handler with automatic schema generation - Updated all providers to use local MCP SDK: - lib/providers/databricks/provider.go - lib/providers/deployment/provider.go - lib/providers/io/provider.go - lib/providers/workspace/provider.go - lib/server/server.go - lib/session/engine_guide.go - lib/trajectory/tracker.go - Removed github.com/modelcontextprotocol/go-sdk from go.mod - Kept github.com/google/jsonschema-go for schema generation All tests pass and linter shows 0 issues. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
Removes the github.com/zeebo/blake3 external dependency and uses the standard library crypto/sha256 instead for computing file checksums in the MCP apps state management. Benefits: - Reduces binary size by ~955 KB (1.72%) - Eliminates external dependency - Uses stable standard library API Both hash implementations follow the same hash.Hash interface, making this a drop-in replacement. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
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Replace the custom databricks.Client wrapper with direct use of the workspace client from context (cmdctx.WorkspaceClient), following the pattern used in the rest of the CLI codebase. Changes: - Remove lib/providers/databricks/client.go - Convert all Client methods to standalone functions that accept context and config parameters - Update provider to get workspace client from context instead of storing a custom client instance - Update deployment provider to pass config instead of client This makes the code consistent with other parts of the CLI and eliminates unnecessary abstraction. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
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This commit removes all Dagger-related code, configuration, and documentation from the codebase. The Dagger sandbox implementation has been replaced with a minimal stub that returns "not implemented" errors. Changes: - Removed Dagger sandbox implementation (dagger.go, dagger_test.go, metrics.go) - Created stub implementation that registers with sandbox factory - Removed `databricks experimental apps-mcp check` command - Removed `--use-dagger` and `--docker-image` CLI flags - Removed DaggerConfig and related fields from ValidationConfig - Simplified validation logic to only use local sandbox - Updated README to remove all Dagger/containerization mentions - Removed dagger.io/dagger dependency from go.mod - Updated doc comments to reflect stub-only status 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
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pietern
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Nov 18, 2025
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Please update the go.mod entries before merging.
Now that it is a single dep it can be included in the main list.
go.mod
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| google.golang.org/api v0.249.0 // indirect | ||
| google.golang.org/genproto/googleapis/rpc v0.0.0-20250922171735-9219d122eba9 // indirect | ||
| google.golang.org/grpc v1.75.1 // indirect | ||
| google.golang.org/grpc v1.76.0 // indirect |
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The other bumps are unrelated, please revert (will come in separately).
| UpdateTime string `json:"update_time"` | ||
| Updater string `json:"updater"` | ||
| URL string `json:"url"` | ||
| } |
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For later PR, these structs duplicate the SDK structs. Why?
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This was an artefact from the port. The Rust version had a vibe-coded SDK. I'll strip that code.
pietern
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Nov 18, 2025
cmd/cmd.go
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| "github.com/databricks/cli/cmd/sync" | ||
| "github.com/databricks/cli/cmd/version" | ||
| "github.com/databricks/cli/cmd/workspace" | ||
| ssh "github.com/databricks/cli/experimental/ssh/cmd" |
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Changes
This PR adds the MCP for building Databricks apps as a new command
databricks experimental mcp.The code is a direct port of the https://github.com/appdotbuild/agent rust code base.
Why
Tests