Data Convert

Convert tabular data files between formats.

Cowork note: If relative paths don't resolve, call mcp__qsv__qsv_get_working_dir and mcp__qsv__qsv_set_working_dir to sync the working directory.

Supported Conversions

Input Formats (auto-detected)

• CSV (.csv), TSV (.tsv/.tab), SSV (.ssv)
• Excel (.xlsx, .xls, .xlsm, .xlsb)
• OpenDocument (.ods)
• JSONL/NDJSON (.jsonl, .ndjson)
• Snappy-compressed variants (.csv.sz, etc.)

Output Formats

Steps

1. Index: Run mcp__qsv__qsv_index on the file for fast random access in subsequent steps.

2. Detect source format: Run mcp__qsv__qsv_sniff to identify the input format, delimiter, and encoding.

3. Convert: Use the appropriate command based on the target format:

   • To CSV (from Excel/JSONL): The MCP server handles this automatically when you pass non-CSV files to any qsv tool. Use mcp__qsv__qsv_command with excel for explicit control over sheet selection.

   • To TSV: Use mcp__qsv__qsv_command with command: "fmt", options: {"out-delimiter": "\t"}.

   • To JSONL: Use mcp__qsv__qsv_command with command: "tojsonl".

   • To Parquet (single file): Use mcp__qsv__qsv_to_parquet (core tool) — auto-generates stats cache and Polars schema for optimal type inference.

   • To Parquet (batch): Use mcp__qsv__qsv_command with command: "to", subcommand: "parquet", destination: "output_dir" for batch conversion with explicit compression control.

   • To XLSX: Use mcp__qsv__qsv_command with command: "to", subcommand: "xlsx", destination: "output.xlsx".

   • To ODS: Use mcp__qsv__qsv_command with command: "to", subcommand: "ods", destination: "output.ods".

   • To SQLite: Use mcp__qsv__qsv_command with command: "to", subcommand: "sqlite", destination: "output.db".

   • To PostgreSQL: Use mcp__qsv__qsv_command with command: "to", subcommand: "postgres", destination: "connection_string".

   • To Data Package: Use mcp__qsv__qsv_command with command: "to", subcommand: "datapackage", destination: "output.json".

4. Verify output: Run mcp__qsv__qsv_count on the output (if CSV-based) to confirm row count matches input.

Notes

• Excel conversion: Use --sheet to specify which sheet to convert (default: first sheet)
• JSONL output respects data types from stats cache - run stats --stats-jsonl first for better type inference
• Parquet conversion preserves data types efficiently and produces smaller files
• For CSV -> CSV reformatting (change delimiter, quoting), use fmt command
• Large Excel files may take longer to convert - the MCP server handles this transparently
• When converting multiple sheets from Excel, run excel with --sheet for each sheet