feat: Add traces, scores, datasets, and sessions tools

[JaviMaligno]

Summary

I've built an extended MCP server that adds 22 tools beyond prompts. I'd like to contribute these to the official MCP server.

Tools Implemented

Category	Tools	Count
Traces	listTraces, getTrace, deleteTrace	3
Observations	listObservations, getObservation	2
Scores	createScore, listScores, getScore, deleteScore	4
Score Configs	createScoreConfig, listScoreConfigs, getScoreConfig	3
Datasets	createDataset, listDatasets, getDataset, createDatasetItem, listDatasetItems, getDatasetItem, deleteDatasetItem, createDatasetRunItem, listDatasetRuns, getDatasetRun	10
Sessions	listSessions, getSession	2

Technical Details

• TypeScript with Zod validation for all inputs
• 59 unit tests + 18 integration tests passing
• Compatible with self-hosted and cloud Langfuse
• Follows the feature module registry pattern from your blog post
• Uses the \ namespace from the JS SDK

Repository

https://github.com/JaviMaligno/langfuse-mcp-server

Related Discussion

I also commented in langfuse/langfuse#5646 where the team mentioned being open for contributions.

Questions

1. What's the preferred approach for contributing these tools?
2. Should I adapt the code to match your existing structure?
3. Any specific conventions or patterns I should follow?

Happy to submit a PR adapting the code to your conventions! 🚀