jinfer

name	jinfer
description	Use jinfer to infer JSON schema from JSON files. Trigger when user wants to understand JSON structure, generate JSON Schema, or inspect the shape of JSON data.

jinfer — JSON Schema Inference

jinfer is a zero-dependency CLI tool and Python library that instantly infers structured schemas from any JSON file. It is installed on this machine and available as the jinfer command. Requires Python 3.10+. Installed via uv tool install jinfer.

When to use

Use jinfer when the user:

• Asks about the structure or shape of a JSON file
• Wants to generate a JSON Schema from sample data
• Needs to inspect or understand what fields and types exist in JSON data
• Has a JSON file and wants a quick overview of its contents
• Wants to validate or document the structure of JSON output

CLI usage

Basic tree view (pretty-printed schema summary):

jinfer <file.json>

Output as JSON Schema (draft-07):

jinfer <file.json> -f json

Limit traversal depth (useful for large or deeply nested files):

jinfer <file.json> -d 3

Pipe from stdin:

cat file.json | jinfer -

Save output to a file:

jinfer <file.json> -f json -o schema.json

Key flags

Flag	Short	Description
--format	-f	Output format: pretty (default) or json (JSON Schema draft-07)
--depth	-d	Limit schema inference depth to N levels
--output	-o	Write output to a file instead of stdout
--no-additional-properties		Set additionalProperties: false on all objects (JSON only)
--refs		Deduplicate repeated object shapes into $defs/$ref (JSON only)
--version	-v	Print the installed version

Python library usage

from jinfer import infer_schema, format_schema, generate_json_schema

# Infer schema from a Python object
schema = infer_schema(data)

# Pretty-print as a tree
print(format_schema(schema))

# Generate JSON Schema draft-07 dict
json_schema = generate_json_schema(schema)

Tips

• For large JSON files, use -d to limit depth first, then increase as needed.
• Use -f json when you need a machine-readable schema for validation or documentation.
• The tree format is best for quick human inspection of structure.
• When piping, use - as the filename to read from stdin.