jinspect 0.4.1

jinspect

A command-line tool that infers the schema of JSON files by sampling their contents. Useful for quickly understanding the shape of large or unfamiliar JSON datasets without reading them manually. Accepts a file path or piped input from stdin.

Given a JSON file or piped JSON, jinspect will tell you:

• What fields exist and their types
• Which fields are optional (with presence counts)
• Array length ranges
• Sample values for leaf fields
• Interactively build jq queries from the inferred schema

Install

dotnet tool install -g jinspect

Or clone and build from source:

dotnet build

Development

This project uses Task as a task runner. Install it with winget install Task.Task, brew install go-task, or see taskfile.dev/installation.

task          # list available tasks
task build    # build the project
task test     # run all tests
task bench    # run benchmarks
task pack     # create NuGet package
task publish  # test, pack, and publish to NuGet (requires NUGET_API_KEY)
task release  # create a GitHub release from the version in the csproj

Usage

jinspect [FILE] [options]

When FILE is omitted, jinspect reads JSON from stdin.

Options:

Examples:

# Inspect a file directly
jinspect data/orders.json

# Sample more elements from a large array
jinspect huge-dataset.json -s 500

# Limit depth for deeply nested structures
jinspect config.json -d 3

# Fuzzy-match a filename
jinspect orders -f

# Pipe JSON from another command
curl -s https://api.example.com/data | jinspect

# Pipe with options
cat data.json | jinspect -s 100 -d 5

Interactive jq query builder

Use --query to navigate the inferred schema and select fields. jinspect outputs a ready-to-run jq command.

# Build a jq query interactively
jinspect data.json -q

# Run the generated query directly
$(jinspect data.json -q)

# Combine with fuzzy matching
$(jinspect orders -fq)

The interactive tree supports:

• ↑↓ / jk to navigate
• → / Enter to expand nodes
• ← to collapse
• Space to toggle field selection
• a to select all, n to clear
• Esc / q to confirm and output the jq command

All UI output goes to stderr, so only the jq command reaches stdout — making it safe for piping and subshells.

Note: -q is not available when reading from stdin, since the interactive UI requires terminal input.

License

MIT