Modifiers

Modifiers let you transform Input Variables directly inside Flow nodes and schemas. The syntax is inspired by Shopify's Liquid. Chain filters with | and pass arguments using : and commas.

Example

{
  "title": "{$input.title | strip | upcase}",
  "summary": "{$input.description | strip_newlines | truncatewords: 20}",
  "tags": "{$input.tags | sort_natural | join: ', '}",
  "slug": "{$input.title | handleize}",
  "price": "{$input.price | divided_by: 100 | round: 2}",
  "fallback": "{$input.optional | default: 'N/A'}"
}

Supported modifiers

Many mirror Liquid’s behavior; key differences are noted below.

Strings

• upcase, downcase
• capitalize
• titlecase
• strip, lstrip, rstrip, strip_newlines
• replace: search, replacement
• replace_first: search, replacement
• replace_last: search, replacement
• remove: search, remove_first: search
• replace_regex: pattern, replacement (regex global)
• truncate: length[, ellipsis] (default length 50, ellipsis "...")
• truncatewords: words[, ellipsis] (default 15, ellipsis "...")
• slice: start[, length] (negative start supported; strings and arrays)
• split: separator
• camelcase
• escape, escape_once (HTML)
• url_encode, url_decode
• strip_html
• newline_to_br
• handle, handleize (slugify with accent removal)
• append: value, prepend: value
• toString, toNumber, toBoolean

Arrays / collections

• reverse (non‑mutating; works on strings too)
• first, last
• uniq
• concat: otherArrayOrValue (non-arrays treated as single-element arrays; nil becomes empty)
• map: key
• where: key[, value] (truthy filter when value omitted; loose string comparison when provided)
• sort[, key]
• sort_natural[, key] (locale-aware, numeric)
• compact (removes null/undefined; keeps false and 0)
• join: separator
• sample (returns a random element from an array)
• parse_json (parses a JSON string into an object/array)
• join: separator
• sample (returns a random element from an array)
• parse_json (parses a JSON string into an object/array)
• group_by: key (groups array of objects by key, returns [{ name, items }])

Numbers / math

• plus: n, minus: n
• times: n (decimal‑safe)
• divided_by: n (guarded, decimal‑aware; returns number)
• modulo: n
• round[: digits] (default 0; improved rounding stability)
• ceil, floor, abs
• at_least: n, at_most: n

Dates

• date: format — strftime-style formatting. Supported tokens include:
  • Basic: %Y %y %m %d %H %I %M %S %p %a %A %b %B %%
  • Advanced: %z (timezone offset), %j (day of year), %s (epoch seconds)

JSON / encoding

• json, jsonify

Control / other

• size (string/array/object length)
• default: value[, allow_false] — when allow_false is 'true', false is considered present; otherwise false is treated as empty
• pluralize: singular, plural

Usage tips

• Chain left to right: {$input.title | strip | upcase}.
• Arguments: {$input.tagline | truncate: 50, '...'}; {$input.tags | join: ', '}.
• Multiple placeholders in a string: missing values become empty strings; a single placeholder that resolves to undefined removes the field.
• reverse is non‑mutating; original arrays aren’t changed.

Examples

String formatting

{
  "headline": "{$input.title | strip | capitalize}",
  "handle": "{$input.title | handleize}",
  "summary": "{$input.body | strip_newlines | truncatewords: 30}",
  "safe_html": "{$input.html | escape_once}",
  "no_tags": "{$input.html | strip_html}",
  "mask_last4": "{$input.code | slice: -4}"
}

Arrays / collections

{
  "first_tag": "{$input.tags | first}",
  "sorted": "{$input.tags | sort_natural | join: ', '}",
  "unique": "{$input.tags | uniq | join: ', '}",
  "pluck_ids": "{$input.items | map: 'id' | compact | join: ','}",
  "filtered_active_count": "{$input.items | where: 'active', true | size}",
  "concat_value": "{$input.tags | concat: 'featured' | join: ', '}"
}

Math / control

{
  "price": "{$input.cents | divided_by: 100 | round: 2}",
  "safe_name": "{$input.name | default: 'Untitled'}",
  "false_ok": "{$input.flag | default: 'fallback', true}",
  "bounded": "{$input.score | at_least: 0 | at_most: 100}"
}

Dates

{
  "short": "{$input.date | date: '%Y-%m-%d'}",
  "with_tz": "{$input.date | date: '%Y-%m-%d %H:%M %z'}",
  "doy": "{$input.date | date: '%j'}",
  "epoch": "{$input.date | date: '%s'}"
}

Additional examples

{
  "parsed": "{$input.json_string | parse_json | json}",
  "random_tag": "{$input.tags | sample}",
  "grouped": "{$input.items | group_by: 'category' | json}",
  "capitalized": "{$input.title | capitalize}",
  "titlecased": "{$input.title | titlecase}",
  "regex_replace": "{$input.text | replace_regex: '\\d+', '[num]'}",
  "keep_false": "{$input.flag | default: 'fallback', 'true'}"
}

Comprehensive examples (one example per filter, ordered to match the lists above)

{
  "upcase": "{$input.name | upcase}",
  "downcase": "{$input.name | downcase}",
  "capitalize": "{$input.title | capitalize}",
  "titlecase": "{$input.title | titlecase}",
  "strip": "{$input.raw | strip}",
  "lstrip": "{$input.raw | lstrip}",
  "rstrip": "{$input.raw | rstrip}",
  "strip_newlines": "{$input.longtext | strip_newlines}",
  "replace": "{$input.greeting | replace: 'Hello', 'Hi' }",
  "replace_first": "{$input.greeting | replace_first: 'o', '0' }",
  "replace_last": "{$input.path | replace_last: '/', '' }",
  "remove": "{$input.body | remove: '<br>' }",
  "remove_first": "{$input.body | remove_first: '<br>' }",
  "replace_regex": "{$input.text | replace_regex: '\\d+', '[num]' }",
  "truncate": "{$input.summary | truncate: 30 }",
  "truncatewords": "{$input.summary | truncatewords: 5 }",
  "slice": "{$input.code | slice: -4 }",
  "split": "{$input.csv | split: ',' }",
  "camelcase": "{$input.phrase | camelcase }",
  "escape": "{$input.html | escape }",
  "escape_once": "{$input.html | escape_once }",
  "url_encode": "{$input.url | url_encode }",
  "url_decode": "{$input.encoded | url_decode }",
  "strip_html": "{$input.html | strip_html }",
  "newline_to_br": "{$input.notes | newline_to_br }",
  "handleize": "{$input.title | handleize }",
  "append": "{$input.name | append: ' Jr.' }",
  "prepend": "{$input.name | prepend: 'Dr. ' }",
  "toString": "{$input.num | toString }",
  "toNumber": "{$input.str_num | toNumber }",
  "toBoolean": "{$input.flag | toBoolean }",

  "reverse": "{$input.items | reverse }",
  "first": "{$input.items | first }",
  "last": "{$input.items | last }",
  "uniq": "{$input.tags | uniq }",
  "concat": "{$input.tags | concat: 'featured' }",
  "map": "{$input.products | map: 'id' }",
  "where": "{$input.products | where: 'available', true }",
  "sort": "{$input.list | sort }",
  "sort_natural": "{$input.list | sort_natural }",
  "compact": "{$input.maybe | compact }",
  "join": "{$input.items | join: ', ' }",
  "sample": "{$input.tags | sample }",
  "parse_json": "{$input.json_text | parse_json }",
  "group_by": "{$input.items | group_by: 'category' }",

  "plus": "{$input.price | plus: 5 }",
  "minus": "{$input.price | minus: 2 }",
  "times": "{$input.qty | times: 2 }",
  "divided_by": "{$input.amount | divided_by: 100 }",
  "modulo": "{$input.count | modulo: 10 }",
  "round": "{$input.value | round: 2 }",
  "ceil": "{$input.value | ceil }",
  "floor": "{$input.value | floor }",
  "abs": "{$input.delta | abs }",
  "at_least": "{$input.score | at_least: 0 }",
  "at_most": "{$input.score | at_most: 100 }",

  "date": "{$input.date | date: '%Y-%m-%d' }",

  "json": "{$input.obj | json }",
  "jsonify": "{$input.obj | jsonify }",

  "size": "{$input.items | size }",
  "default": "{$input.whatever | default: 'fallback' }",
  "pluralize": "{$input.count | pluralize: 'item', 'items' }"
}