jgravelle/jdatamunch-mcp
View on GitHub ↗Token-efficient MCP server for tabular data retrieval. Index CSV/Excel files, query rows, aggregate — 99%+ token savings vs raw file reads.
81 ★19 forksPythonUpdated 18d ago
What you need to know
Local-first MCP server that answers questions about CSV, Excel, Parquet, and JSONL files by profiling a dataset once and running column profiles, filtered rows, aggregations, and joins server-side, so a million-row file costs thousands of tokens instead of millions.
Install
claude mcp add jdatamunch -- uvx jdatamunch-mcp claude mcp add jdatamunch -- uvx --from "jdatamunch-mcp[excel,parquet]" jdatamunch-mcp uv tool install jdatamunch-mcp pipx install jdatamunch-mcp
Usage
- •No separate indexing command: ask the agent to index a file and it calls index_local, returning the dataset name, row/column counts, and detected types.
- •Orient with describe_dataset / describe_column, then query without loading rows via get_rows, aggregate, or run_sql.
- •Work across datasets with suggest_joins, suggest_keys, and join_datasets; index CSVs/Excel/Parquet/JSONL straight from GitHub with index_repo.
- •Requires Python 3.10+ and any MCP-compatible client; Excel and Parquet need the matching optional extras.
Key features
- ✓39 tools covering orientation, server-side query, data quality (get_dataset_health, get_data_hotspots), schema-drift checks, and semantic search.
- ✓Aggregations and filters execute against stored data rather than being simulated in the model.
- ✓Sampled statistics report error bounds (roughly 2% standard error) instead of presenting estimates as exact.
- ✓Local-first with opt-out anonymous savings counter; no data, column names, file paths, or PII uploaded.
- ✓Implements the jMRI retrieval spec with token accounting shared across the jMunch suite.
Best for
Analysts and coding agents that need to explore large tabular datasets (CSV/Excel/Parquet/JSONL) without dumping rows into the context window.
Caveats
- ⚠Free for personal use; commercial use requires a paid one-time license (from $39) sold by jMunch LLC.
- ⚠Token savings scale with file size — negligible on small spreadsheets.
- ⚠Excel and Parquet support require optional extras that pull extra dependencies.
- ⚠Does not read code or prose; those belong to the sibling jcodemunch-mcp and jdocmunch-mcp servers.
- ⚠Default describe_column is not labeled offloadable when index freshness is unknown.
Platforms: LocalClients: Claude Code · Claude Desktop · Cursor · Windsurf
Reviewed 2026-08-18
Topics
claudeclaude-codecodexcopilotcsvcursordata-analysisdata-explorationdeveloper-toolsexcelgemini-clillmmcpmcp-servermodel-context-protocolspreadsheetsqltabular-datatoken-optimizationwindsurf
- Stars
- 81★
- Forks
- 19
- Language
- Python
- License
- NOASSERTION
- Created
- 2026-03-25
- Last push
- 2026-08-17