CLI Reference
Complete reference for every FineType command — flags, defaults, and examples.
FineType ships as a single binary with five commands. Together they form a pipeline from raw text to typed, validated, query-ready tables.
Commands
| Command | Description |
|---|---|
infer | Classify a single value or batch of values into semantic types |
profile | Profile a CSV file — detect the semantic type of every column |
validate | Validate CSV or Parquet against a JSON Schema — and optionally materialise a typed DuckDB table |
taxonomy | Browse and filter the type taxonomy — and export per-type JSON Schemas |
mcp | Start the MCP server, exposing type inference to AI agents over stdio |
The pipeline
The commands map to a natural workflow:
- Explore — use
inferto classify individual values and build intuition about your data. - Discover — use
profileto scan an entire CSV and see what FineType detects in every column. - Capture the contract — export a JSON Schema: per type with
taxonomy "<glob>" -o json-schema, or for a whole file withprofile -f data.csv -o json-schema(add--statsfor observed-data constraints). - Validate & materialise — use
validate data.csv schema.json --db out.db --table ordersto gate the data and cast it into a typed DuckDB table in a single pass.
You don't have to use every step. profile alone gives you a quick answer; validate with --db/--table takes you from CSV to a typed, validated table in one command. The pipeline is there when you need rigour.
Getting started
If you're new to FineType, start with the Quick Start guide for a hands-on walkthrough covering installation, profiling, and schema export.
Output formats
Every command that produces output supports multiple formats via the -o / --output flag:
| Format | Flag value | Use case |
|---|---|---|
| Plain text | plain | Human-readable terminal output (default) |
| JSON | json | Programmatic consumption, piping to jq |
| CSV | csv | Spreadsheets, further analysis |
| Markdown | markdown | Documentation, reports |
| Arrow | arrow | High-performance IPC, streaming to DuckDB |
| JSON Schema | json-schema | Machine-readable type contracts (profile, taxonomy) |