Qsv data-convert

Convert between CSV, TSV, Excel, JSONL, Parquet, and other tabular formats

install

source · Clone the upstream repo

git clone https://github.com/dathere/qsv

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/dathere/qsv "$T" && mkdir -p ~/.claude/skills && cp -r "$T/.claude/skills/skills/data-convert" ~/.claude/skills/dathere-qsv-data-convert && rm -rf "$T"

manifest: .claude/skills/skills/data-convert/SKILL.md

source content

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

Format	Command	Extension
CSV	`select` (identity) or `fmt`	`.csv`
TSV	`fmt --out-delimiter '\t'`	`.tsv`
JSONL	`tojsonl`	`.jsonl`
JSON	`slice --json`	`.json`
Parquet	`mcp__qsv__qsv_to_parquet` (core tool)	`.parquet`
XLSX	`to xlsx` (via `mcp__qsv__qsv_command` )	`.xlsx`
ODS	`to ods` (via `mcp__qsv__qsv_command` )	`.ods`
SQLite	`to sqlite` (via `mcp__qsv__qsv_command` )	`.db`
PostgreSQL	`to postgres` (via `mcp__qsv__qsv_command` )	N/A
Data Package	`to datapackage` (via `mcp__qsv__qsv_command` )	`.json`

Steps

Index: Run
```
mcp__qsv__qsv_index
```
on the file for fast random access in subsequent steps.
Detect source format: Run
```
mcp__qsv__qsv_sniff
```
to identify the input format, delimiter, and encoding.

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"

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