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Quick Start

jpx is a command-line JSON processor with 400+ built-in functions. Pipe JSON in, get transformed JSON out.

Five things to know to start using it:

1. Get a field

echo '{"name": "Alice", "city": "NYC"}' | jpx 'name'
# "Alice"

Nested fields use dots:

echo '{"user": {"name": "Alice"}}' | jpx 'user.name'
# "Alice"

2. Get all items from an array

Use [*] to get every element:

echo '[{"name": "Alice"}, {"name": "Bob"}]' | jpx '[*].name'
# ["Alice", "Bob"]

3. Filter an array

Use [?condition] to filter:

echo '[{"name": "Alice", "age": 30}, {"name": "Bob", "age": 25}]' | jpx '[?age > `28`]'
# [{"name": "Alice", "age": 30}]

Note: literal values use backticks (`28`).

4. Call a function

jpx has 400+ functions. Pass data with @ (current value):

echo '[3, 1, 4, 1, 5]' | jpx 'sort(@)'
# [1, 1, 3, 4, 5]

echo '[3, 1, 4, 1, 5]' | jpx 'unique(@)'
# [3, 1, 4, 5]

echo '{"name": "hello"}' | jpx 'upper(name)'
# "HELLO"

5. Chain with pipes

Combine operations with |:

echo '[{"n": "Alice"}, {"n": "Bob"}, {"n": "Alice"}]' | jpx '[*].n | unique(@) | sort(@)'
# ["Alice", "Bob"]

That’s it. You can do a lot with just these five patterns.

Finding Functions

Don’t memorize 400 functions. Search for what you need:

jpx --search unique
jpx --describe unique

Next Steps