jq

Apps & Automation

Use when working with the jq command-line JSON processor — filters, builtins, operators, path expressions, assignments, variables, functions, regex, format strings, dates, modules, invocation flags, and exit codes. Triggers on: "jq", "jq filter", "jq program", "jq query", "jq language", "jq manual", "jq builtin", "jq regex", "jq module", "jq reduce", "jq foreach", "jq select", "jq walk", "jq recurse", "jq map", "jq inputs", "jq slurp", "jq --arg", "jq --argjson", "jq --null-input", "jq --raw-output", "jq @base64", "jq @csv", "jq @sh", "jq @uri", "jq tojson", "jq fromjson", "jq todate", "jq fromdate", "jq strptime", "jq strftime", "jq now", "jq $ENV", "jq env", "jq getpath", "jq setpath", "jq del", "jq paths", "jq sort", "jq group_by", "jq sub", "jq gsub", "jq test", "jq match", "jq with_entries", "jq map_values", "jq modulemeta", "jq import", "jq input", "jq --stream", "jq --exit-status", "jq --compact-output", "jq //", "jq destructuring", "jq label", "jq break", "jq try", "jq catch", "jq INDEX", "jq JOIN".

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jq — Command-line JSON Processor In-Depth Reference

Comprehensive reference for the jq language and CLI — filters, builtin functions, operators, path expressions, assignments, variables, functions, regex, format strings, dates, modules, and invocation. Covers jq 1.7. Source: https://jqlang.github.io/jq/manual/.

Data Flow

Input (stdin / files / --null-input)
  → JSON parser (stream of whitespace-separated values)
    → filter program (pipeline of filters, one input → zero or more outputs)
      → output formatter (--compact-output, --raw-output, --tab, --indent, --sort-keys)
        → stdout (newline-separated JSON texts)

A jq program is a single filter expression. Every filter takes one input and produces zero or more outputs. Filters compose with | (pipe), , (comma), and operators. Multiple outputs from one stage are fed one-by-one into the next — this is the generator model at the heart of jq.

Sub-Resources

Load the reference that matches your task. When in doubt, load multiple references.

Keywords	Reference
invocation, command line, flags, options, --null-input, -n, --raw-input, -R, --slurp, -s, --compact-output, -c, --raw-output, -r, --raw-output0, --join-output, -j, --ascii-output, -a, --sort-keys, -S, --color-output, -C, --monochrome-output, -M, --tab, --indent, --unbuffered, --stream, --stream-errors, --seq, --from-file, -f, -L, --library-path, --arg, --argjson, --slurpfile, --rawfile, --args, --jsonargs, --exit-status, -e, --binary, -b, --version, -V, --build-configuration, --help, -h, --run-tests, --, exit status, exit code, JQ_COLORS, NO_COLOR, $ENV, env, $ARGS, shell quoting, stdin, files	references/cli.md
filter, identity, ., .foo, .foo.bar, .foo?, optional, object index, .["foo"], array index, .[0], negative index, slice, .[2:4], .[:3], .[-2:], value iterator, .[], .[]?, comma, pipe,	, parenthesis, recursive descent, .., basic filter
type, value, number, string, boolean, null, array, object, array construction, [], object construction, {}, shortcut syntax, {user, title}, key expression, variable key, {$foo}, IEEE754, double precision, number literal, precision	references/types.md
addition, +, subtraction, -, multiplication, *, division, /, modulo, %, abs, length, utf8bytelength, arithmetic, array concatenation, string concatenation, object merge, null addition, comparison, ==, !=, >, >=, <=, <, and, or, not, truthiness, alternative operator, //, default value, sort order	references/operators.md
builtin, function, keys, keys_unsorted, has, in, map, map_values, pick, select, arrays, objects, iterables, booleans, numbers, normals, finites, strings, nulls, values, scalars, empty, error, halt, halt_error, $loc, paths, add, any, all, flatten, range, floor, sqrt, tonumber, tostring, type, infinite, nan, isnan, isinfinite, isfinite, isnormal, sort, sort_by, group_by, min, max, min_by, max_by, unique, unique_by, reverse, contains, indices, index, rindex, inside, startswith, endswith, combinations, ltrimstr, rtrimstr, explode, implode, split, join, ascii_downcase, ascii_upcase, while, repeat, until, recurse, walk, transpose, bsearch, builtins, getpath, setpath, delpaths, to_entries, from_entries, with_entries, path, del	references/builtins.md
conditional, if, then, else, elif, end, try, catch, ?, error suppression, optional operator, reduce, foreach, label, break, breaking out, control structure, generators, iterator, tail call, recursion	references/control.md
variable, binding, as, $name, destructuring, pattern, ?//, alternative, def, function definition, function argument, scoping, lexical scope, filter argument, callback, value argument, addvalue, isempty, limit, skip, first, last, nth	references/variables-functions.md
path, path expression, path(f), getpath, setpath, delpaths, del, pick, assignment, =, update assignment,	=, arithmetic update, +=, -=, *=, /=, %=, //=, complex assignment, LHS, RHS, immutable, deep copy, posts, comments
string, interpolation, (exp), tojson, fromjson, tostring, tonumber, length, utf8bytelength, split, join, ltrimstr, rtrimstr, startswith, endswith, explode, implode, ascii_downcase, ascii_upcase, ascii, test, match, capture, scan, sub, gsub, splits	references/strings.md
regex, regular expression, Oniguruma, Perl NG, test, match, capture, scan, split, splits, sub, gsub, flags, g, i, m, n, p, s, l, x, named group, capturing group, offset, length	references/regex.md
format string, @text, @json, @html, @uri, @csv, @tsv, @sh, @base64, @base64d, escaping, percent-encoding, CSV, TSV, shell escaping, HTML entity, string interpolation, @foo	references/formats.md
date, time, fromdate, todate, fromdateiso8601, todateiso8601, now, strptime, strftime, strflocaltime, mktime, gmtime, localtime, broken down time, Unix epoch, ISO 8601, UTC, timezone	references/dates.md
module, import, include, module directive, modulemeta, .jq, search path, -L, $ORIGIN, ~, metadata, deps, defs, I/O, input, inputs, input_filename, input_line_number, debug, stderr, INDEX, JOIN, IN, SQL, $ENV, env, $JQ_BUILD_CONFIGURATION	references/modules.md

Quick Guide

How do I invoke jq and what do the flags do? → references/cli.md
How do I write a basic filter (., .foo, .[], |)? → references/filters.md
What types does jq support and how do I construct arrays/objects? → references/types.md
How do arithmetic, comparison, and boolean operators work? → references/operators.md
What builtin functions are available (map, select, add, sort, etc.)? → references/builtins.md
How do if/try/reduce/foreach and label/break work? → references/control.md
How do I bind variables (as $x) and define functions (def)? → references/variables-functions.md
How do path expressions and assignment operators (=, |=, +=) work? → references/paths-assignment.md
What string functions exist (split, join, interpolation, etc.)? → references/strings.md
How do jq regular expressions work (test, match, sub, gsub, flags)? → references/regex.md
What are the @foo format strings and how do they escape? → references/formats.md
How do I parse and format dates in jq? → references/dates.md
How do modules, I/O builtins, and SQL-style operators work? → references/modules.md
How do I pass variables from the command line (--arg, --argjson)? → references/cli.md
What exit codes does jq use? → references/cli.md
How do I read input from files or use --null-input? → references/cli.md
How do I configure output formatting (compact, raw, tab, indent)? → references/cli.md
How does --stream mode work? → references/cli.md
How do I debug a jq program (debug, stderr)? → references/modules.md
What is the // alternative operator? → references/operators.md
How does destructuring with ?// work? → references/variables-functions.md
How do I break out of a reduce or foreach? → references/control.md

Cross-Project References

For carapace-specific jq integration (the jq completer in completers/common/jq_completer/), see the carapace-dev skill → references/action.md. The completer itself only covers CLI flags and file/directory arguments — it does not complete the jq filter language.
For shell quoting rules that affect how jq programs are passed on the command line, see the bash, zsh, or fish skills as appropriate for the target shell.