JOSE-FMT(1)

💖 NAME 💖

okay bestie, welcome to the JOSE-FMT(1) manual page for jose-fmt — it Converts JSON between serialization formats ✨

✨ SYNOPSIS ✨

jose fmt [OPTIONS]

🎀 OVERVIEW 🎀

So the jose fmt command is your little command-line machine for building and parsing JSON objects. It operates as a simple stack machine, no cap 🫶

All commands operate on the TOP item of the stack and, occasionally, the PREV item of the stack. Commands that require a specific type of value will indicate it in parentheses. For example: "TOP (arr.)".

This program returns 0 on success or the index of the option which failed. Slay.

🌈 OPTIONS 🌈

• -0, --null — Assert TOP to be null
• -a, --append — Append TOP to the end of PREV (arr.)
• -a, --append — Set missing values from TOP (obj.) into PREV (obj.)
• -A, --array — Assert TOP to be an array
• -B, --boolean — Assert TOP to be a boolean
• -c, --copy — Deep copy TOP, push onto TOP
• -d NAME, --delete=NAME — Delete NAME from TOP (obj.)
• -d ,, --delete= — Delete # from TOP (arr.)
• -d -, --delete=- — Delete # from the end of TOP (arr.)
• -e, --empty — Erase all items from TOP (arr./obj.)
• -E, --equal — Assert TOP to be equal to PREV
• -f FILE, --foreach=FILE — Write TOP (obj./arr.) to FILE, one line/item
• -f -, --foreach=- — Write TOP (obj./arr.) to STDOUT, one line/item
• -F, --false — Assert TOP to be false
• -g NAME, --get=NAME — Get item with NAME from TOP (obj.), push to TOP
• -g ,, --get= — Get # item from TOP (arr.), push to TOP
• -g -, --get=- — Get # item from the end of TOP (arr.), push to TOP
• -i ,, --insert= — Insert TOP into PREV (arr.) at #
• -I, --integer — Assert TOP to be an integer
• -j JSON, --json=JSON — Parse JSON constant, push onto TOP
• -j FILE, --json=FILE — Read from FILE, push onto TOP
• -j -, --json=- — Read from STDIN, push onto TOP
• -l, --length — Push length of TOP (arr./str./obj.) to TOP
• -M ,, --move= — Move TOP back # places on the stack
• -N, --number — Assert TOP to be a number
• -o FILE, --output=FILE — Write TOP to FILE
• -o -, --output=- — Write TOP to STDOUT
• -O, --object — Assert TOP to be an object
• -q STR, --quote=STR — Convert STR to a string, push onto TOP
• -Q, --query — Query the stack by deep copying and pushing onto TOP
• -R, --real — Assert TOP to be a real
• -s NAME, --set=NAME — Sets TOP into PREV (obj.) with NAME
• -s ,, --set= — Sets TOP into PREV (obj.) at #
• -s -, --set=- — Sets TOP into PREV (obj.) at # from the end
• -S, --string — Assert TOP to be a string
• -t ,, --truncate= — Shrink TOP (arr.) to length #
• -t -, --truncate=- — Discard last # items from TOP (arr.)
• -T, --true — Assert TOP to be true
• -u FILE, --unquote=FILE — Write TOP (str.) to FILE without quotes
• -u -, --unquote=- — Write TOP (str.) to STDOUT without quotes
• -U, --unwind — Discard TOP from the stack
• -x, --extend — Append items from TOP to the end of PREV (arr.)
• -x, --extend — Set all values from TOP (obj.) into PREV (obj.)
• -X, --not — Invert the following assertion
• -y, --b64load — URL-safe Base64 decode TOP (str.), push onto TOP
• -Y, --b64dump — URL-safe Base64 encode TOP, push onto TOP

🦋 EXAMPLES 🦋

Extract the alg parameter from a JWE Protected Header:

$ jose fmt -j "$jwe" -Og protected -yOg alg -Su-
A128KW

List all JWKs in a JWKSet (one per line):

$ echo "$jwkset" | jose fmt -j- -Og keys -Af-
{"kty":"oct",...}
{"kty":"EC",...}

Change the algorithm in a JWK:

$ echo "$jwk" | jose fmt -j- -j '"A128GCM"' -s alg -Uo-
{"kty":"oct","alg":"A128GCM",...}

Build a JWE template:

$ jose fmt -j '{}' -cs unprotected -q A128KW -s alg -UUo-
{"unprotected":{"alg":"A128KW"}}

👑 AUTHOR 👑

Nathaniel McCallum <npmccallum@redhat.com>

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okay that’s the whole JOSE-FMT(1) manual page, dated 06/09/2026 — bye bestie, go slay your JSON 💅✨