FLEX Function Reference - FalkorDB Docs

FLEX is FalkorDB’s open source community UDF package, available at github.com/FalkorDB/flex.
It contains a variety of useful functionality, including:

String and set similarity metrics for fuzzy matching and comparison
Date and time manipulation, formatting, and parsing
Low-level bitwise operations on integers

We welcome contributions to extend this library with additional functionality. The following sections document all FLEX (FalkorDB Library for Extensions) functions.

Function Categories

Similarity Functions (`flex.sim.*`)

Set similarity metrics for fuzzy matching and comparison.

Function	Description
sim.jaccard	Calculate Jaccard similarity coefficient between sets

Text Functions (`flex.text.*`)

String manipulation, formatting, case conversion utilities, and string similarity metrics.

Function	Description
text.capitalize	Capitalize the first character of a string
text.decapitalize	Lowercase the first character of a string
text.swapCase	Swap the case of all characters in a string
text.camelCase	Convert string to camelCase format
text.upperCamelCase	Convert string to UpperCamelCase (PascalCase)
text.snakeCase	Convert string to snake_case format
text.format	Format string with placeholder substitution
text.indexOf	Find first occurrence of substring
text.indexesOf	Find all occurrences of substring
text.join	Join array elements with delimiter
text.lpad	Pad string on the left to target length
text.rpad	Pad string on the right to target length
text.regexGroups	Extract regex matches and capture groups
text.repeat	Repeat string multiple times
text.replace	Replace text using regex pattern
text.jaroWinkler	Compute Jaro-Winkler similarity for short strings
text.levenshtein	Compute Levenshtein edit distance between strings

Collection Functions (`flex.coll.*`)

Operations on lists and arrays including set operations and transformations.

Function	Description
coll.zip	Combine two lists element-by-element into pairs
coll.union	Combine lists and return unique elements
coll.intersection	Find common elements between lists
coll.shuffle	Randomly shuffle list elements
coll.frequencies	Count frequency of each element in list

Map Functions (`flex.map.*`)

Map/object manipulation for property management and transformation.

Function	Description
map.merge	Shallow merge multiple maps
map.fromPairs	Convert list of key-value pairs to map
map.submap	Extract subset of keys from map
map.removeKey	Remove single key from map
map.removeKeys	Remove multiple keys from map

JSON Functions (`flex.json.*`)

JSON serialization and parsing utilities.

Function	Description
json.toJson	Serialize value to JSON string
json.fromJsonMap	Parse JSON string to map
json.fromJsonList	Parse JSON string to list

Date Functions (`flex.date.*`)

Date and time manipulation, formatting, and parsing.

Function	Description
date.format	Format date/time with pattern and timezone
date.parse	Parse date/time string with optional pattern
date.truncate	Truncate date to specific unit (day, month, etc.)
date.toTimeZone	Convert date to timezone offset

Bitwise Functions (`flex.bitwise.*`)

Low-level bitwise operations on integers.

Function	Description
bitwise.and	Bitwise AND operation
bitwise.or	Bitwise OR operation
bitwise.xor	Bitwise XOR (exclusive OR) operation
bitwise.not	Bitwise NOT (one’s complement) operation
bitwise.shiftLeft	Left bit shift operation
bitwise.shiftRight	Right bit shift with sign extension

Common Use Cases

Data Cleaning and Normalization

text.camelCase, text.snakeCase - Normalize field names
text.replace - Remove or sanitize unwanted characters
coll.union - Deduplicate lists

Fuzzy Matching and Search

text.levenshtein - Find similar strings with edit distance
text.jaroWinkler - Match names and short strings
sim.jaccard - Compare sets and tag similarity

Data Aggregation and Analysis

date.truncate - Group by time periods
coll.frequencies - Count occurrences
map.submap - Select relevant fields

API and Data Exchange

json.toJson, json.fromJsonMap - JSON serialization
map.removeKeys - Filter sensitive data
text.format - Build formatted messages

Permission and Flag Management

bitwise.and, bitwise.or - Check and set permission flags
bitwise.xor - Toggle flags

Frequently Asked Questions

What is the FLEX library?

FLEX (FalkorDB Library for Extensions) is FalkorDB’s open-source community UDF package. It provides ready-to-use functions for text manipulation, date/time handling, JSON processing, collections, maps, bitwise operations, and similarity metrics.

How do I call FLEX functions in Cypher?

FLEX functions use the namespace pattern flex.<category>.<function>(). For example: flex.text.camelCase('hello world') or flex.sim.jaccard(list1, list2).

Do I need to install FLEX separately?

Yes. FLEX is available at github.com/FalkorDB/flex and must be loaded into your FalkorDB instance as a UDF library before use.

Can I contribute new functions to FLEX?

Yes! FLEX is open source and welcomes community contributions. Visit the FLEX GitHub repository to submit new functions or improvements.

​Function Categories

​Similarity Functions (flex.sim.*)

​Text Functions (flex.text.*)

​Collection Functions (flex.coll.*)

​Map Functions (flex.map.*)

​JSON Functions (flex.json.*)

​Date Functions (flex.date.*)

​Bitwise Functions (flex.bitwise.*)

​Common Use Cases

​Data Cleaning and Normalization

​Fuzzy Matching and Search

​Data Aggregation and Analysis

​API and Data Exchange

​Permission and Flag Management

​Frequently Asked Questions