Built-in Functions

This reference is designed for both human developers and AI coding agents. Every entry includes complete syntax that can be used directly in queries.

83 built-in functions across 9 categories: Aggregation (11), String (23), Math (17), Type Conversion (5), Graph Introspection (6), Node Metadata (5), Map and List (4), Date/Time (4), Utility (4), and Predicates (4).

Aggregation (11)#

Aggregation functions operate across rows in a result set. Use with or without GROUP BY (via WITH).

Function	Syntax	Description	Return Type	Since
`count`	`count(expr)`	Number of non-null values	Integer	0.4.0
`count(DISTINCT)`	`count(DISTINCT expr)`	Number of distinct non-null values	Integer	0.4.0
`sum`	`sum(expr)`	Sum of numeric values	Float	0.4.0
`avg`	`avg(expr)`	Arithmetic mean	Float	0.4.0
`min`	`min(expr)`	Minimum value	Same as input	0.4.0
`max`	`max(expr)`	Maximum value	Same as input	0.4.0
`collect`	`collect(expr)`	Collect values into a list	List	0.4.0
`percentile`	`percentile(expr, p)`	Percentile value (p between 0.0 and 1.0)	Float	4.0.0
`stdev`	`stdev(expr)`	Sample standard deviation	Float	4.0.0
`variance`	`variance(expr)`	Sample variance	Float	4.0.0
`median`	`median(expr)`	Median (50th percentile)	Float	4.0.0

MATCH (n:Person)
RETURN count(n) AS total, avg(n.age) AS avgAge, percentile(n.score, 0.95) AS p95

MATCH (n:Person)
WITH n.department AS dept, collect(n.name) AS members, stdev(n.salary) AS salaryStdev
RETURN dept, members, salaryStdev

String (23)#

Function	Syntax	Description	Return Type	Since
`toLower`	`toLower(s)`	Convert to lowercase	String	0.17.0
`toUpper`	`toUpper(s)`	Convert to uppercase	String	0.17.0
`trim`	`trim(s)`	Strip leading and trailing whitespace	String	0.17.0
`ltrim`	`ltrim(s)`	Strip leading whitespace	String	4.0.0
`rtrim`	`rtrim(s)`	Strip trailing whitespace	String	4.0.0
`substring`	`substring(s, start, len)`	Extract substring from start position	String	0.17.0
`left`	`left(s, n)`	First n characters	String	0.17.0
`right`	`right(s, n)`	Last n characters	String	0.17.0
`head`	`head(expr)`	First element of a list or comma-separated string	Same as element	3.0.0
`last`	`last(expr)`	Last element of a list or comma-separated string	Same as element	3.0.0
`replace`	`replace(s, find, rep)`	Replace all occurrences of find with rep	String	0.17.0
`split`	`split(s, delim)`	Split string by delimiter into list	List	0.17.0
`reverse`	`reverse(s)`	Reverse a string or comma-separated list	String	0.17.0
`sort`	`sort(expr)`	Alphabetically sort comma-separated string values	String	4.0.0
`repeat`	`repeat(s, n)`	Repeat string n times	String	4.0.0
`lpad`	`lpad(s, width, char)`	Left-pad string to width with char	String	4.0.0
`rpad`	`rpad(s, width, char)`	Right-pad string to width with char	String	4.0.0
`contains`	`contains(s, sub)`	True if string contains substring	Boolean	4.0.0
`startsWith`	`startsWith(s, prefix)`	True if string starts with prefix	Boolean	4.0.0
`endsWith`	`endsWith(s, suffix)`	True if string ends with suffix	Boolean	4.0.0
`indexOf`	`indexOf(s, sub)`	Position of substring, -1 if not found	Integer	4.0.0
`size`	`size(s)`	Length of string or list	Integer	0.10.0
`toString`	`toString(expr)`	Convert any value to string representation	String	0.10.0

MATCH (n:Person)
RETURN toLower(n.name) AS lower, left(n.name, 3) AS initials, size(n.name) AS len

MATCH (n:Person)
WHERE startsWith(n.email, 'admin')
RETURN n.name, replace(n.email, '@old.com', '@new.com') AS newEmail

MATCH (n:Person)
RETURN lpad(toString(n.id), 6, '0') AS paddedId, repeat('*', n.rating) AS stars

Math (17)#

Function	Syntax	Description	Return Type	Since
`abs`	`abs(expr)`	Absolute value	Float	4.0.0
`round`	`round(expr)`	Round to nearest integer	Float	4.0.0
`ceil`	`ceil(expr)`	Ceiling (round up)	Float	4.0.0
`floor`	`floor(expr)`	Floor (round down)	Float	4.0.0
`sqrt`	`sqrt(expr)`	Square root	Float	4.0.0
`sign`	`sign(expr)`	Signum: -1, 0, or 1	Float	4.0.0
`exp`	`exp(expr)`	e raised to the power of the value	Float	4.0.0
`log`	`log(expr)`	Natural logarithm (ln)	Float	4.0.0
`log10`	`log10(expr)`	Base-10 logarithm	Float	10.0.0
`log2`	`log2(expr)`	Base-2 logarithm	Float	10.0.0
`power`	`power(base, exp)`	Raise base to exponent	Float	4.0.0
`sin`	`sin(expr)`	Sine (radians)	Float	4.0.0
`cos`	`cos(expr)`	Cosine (radians)	Float	4.0.0
`tan`	`tan(expr)`	Tangent (radians)	Float	4.0.0
`atan2`	`atan2(y, x)`	Arctangent of y/x (radians)	Float	4.0.0
`pi`	`pi()`	Pi constant (3.14159...)	Float	4.0.0
`e`	`e()`	Euler's number (2.71828...)	Float	4.0.0

MATCH (n:Sensor)
RETURN n.name, abs(n.reading) AS magnitude, round(n.value * 100) / 100 AS rounded

MATCH (n:Point)
RETURN atan2(n.y, n.x) AS angle, sqrt(power(n.x, 2) + power(n.y, 2)) AS distance

Type Conversion (5)#

Function	Syntax	Description	Return Type	Since
`toString`	`toString(expr)`	Convert to string	String	0.10.0
`toInteger`	`toInteger(expr)`	Convert to integer	Integer	0.10.0
`toFloat`	`toFloat(expr)`	Convert to float	Float	0.10.0
`toBoolean`	`toBoolean(expr)`	Convert to boolean	Boolean	4.0.0
`coalesce`	`coalesce(a, b, ...)`	First non-null value	Same as first non-null	0.10.0

MATCH (n:Person)
RETURN toInteger(n.ageStr) AS age, coalesce(n.nickname, n.name) AS displayName

Graph Introspection (6)#

Function	Syntax	Description	Return Type	Since
`id`	`id(n)`	Internal node or relationship ID	Integer	0.8.0
`labels`	`labels(n)`	List of labels on a node	List<String>	0.8.0
`type`	`type(r)`	Relationship type string	String	0.8.0
`degree`	`degree(n)`	Total degree (in + out)	Integer	3.0.0
`inDegree`	`inDegree(n)`	Incoming relationship count	Integer	3.0.0
`outDegree`	`outDegree(n)`	Outgoing relationship count	Integer	3.0.0

MATCH (n:Person)
RETURN n.name, degree(n) AS connections, inDegree(n) AS followers, outDegree(n) AS following
ORDER BY degree(n) DESC

Node Metadata (5)#

ArcFlow world-model metadata functions for provenance and trust scoring.

Function	Syntax	Description	Return Type	Since
`confidence`	`confidence(n)`	World-model confidence score (0.0-1.0)	Float	4.0.0
`observationClass`	`observationClass(n)`	Observation class: observed, inferred, or predicted	String	4.0.0
`authorityPlane`	`authorityPlane(n)`	Authority plane: semantic or scene	String	4.0.0
`clockDomain`	`clockDomain(n)`	Temporal clock domain name	String	4.0.0
`observationSource`	`observationSource(n)`	Source identity (sensor, model, user)	String	4.0.0

MATCH (n:Observation)
WHERE confidence(n) > 0.8 AND observationClass(n) = 'observed'
RETURN n.name, confidence(n) AS conf, authorityPlane(n) AS plane

Map and List (4)#

Function	Syntax	Description	Return Type	Since
`properties`	`properties(n)`	Full property map as string	String	4.0.0
`keys`	`keys(n)`	List of property key names	List<String>	3.0.0
`range`	`range(start, end)`	Generate integer sequence [start..=end]	List<Integer>	4.0.0
`mapProjection`	`n {.name, .age}`	Return only named properties as a map	Map	4.0.0

MATCH (n:Person)
RETURN keys(n) AS propKeys, properties(n) AS allProps

MATCH (n:Person)
RETURN n {.name, .age} AS profile

UNWIND range(1, 10) AS i
RETURN i

Date/Time (4)#

All date/time functions are non-deterministic (they return the current time).

Function	Syntax	Description	Return Type	Since
`timestamp`	`timestamp()`	Current Unix timestamp in milliseconds	Integer	4.0.0
`date`	`date()`	Current date as ISO string (YYYY-MM-DD)	String	4.0.0
`time`	`time()`	Current time as ISO string (HH:MM:SS.mmm)	String	4.0.0
`datetime`	`datetime()`	Current datetime as ISO string (YYYY-MM-DDTHH:MM:SS.mmm)	String	4.0.0

CREATE (e:Event {name: 'deploy', createdAt: timestamp(), date: date()})
RETURN e

Utility (4)#

Function	Syntax	Description	Return Type	Since
`randomUUID`	`randomUUID()`	Generate a UUID v4 string	String	4.0.0
`hash`	`hash(expr)`	Deterministic FNV-1a 64-bit hash as hex string	String	4.0.0
`toJson`	`toJson(n)`	Serialize all node properties to JSON string	String	4.0.0
`size`	`size(expr)`	Length of string or list	Integer	0.10.0

CREATE (n:Record {id: randomUUID(), fingerprint: hash(n.data)})
RETURN n

MATCH (n:Person)
RETURN toJson(n) AS json

Predicates (4)#

Predicate expressions used in WHERE clauses and RETURN.

Predicate	Syntax	Description	Return Type	Since
`exists`	`exists(n.prop)`	True if property exists	Boolean	0.6.0
`IS NULL`	`n.prop IS NULL`	True if property is null or missing	Boolean	0.15.0
`IS NOT NULL`	`n.prop IS NOT NULL`	True if property exists and is not null	Boolean	0.15.0
`IN`	`expr IN [list]`	True if value is in the list	Boolean	0.20.0

MATCH (n:Person)
WHERE exists(n.email) AND n.role IN ['admin', 'editor']
RETURN n.name

MATCH (n:Person)
WHERE n.deletedAt IS NULL
RETURN n.name

Path Functions (3)#

Functions for operating on path values bound with MATCH p = ....

Function	Syntax	Description	Return Type
`nodes`	`nodes(path)`	Ordered list of nodes along the path	List<Node>
`relationships`	`relationships(path)`	Ordered list of relationships along the path	List<Rel>
`length`	`length(path)`	Number of relationships in the path	Integer

MATCH p = (a:Person {name: 'Alice'})-[*..5]->(b:Person {name: 'Dave'})
RETURN length(p) AS hops, [n IN nodes(p) | n.name] AS names

List Operations#

List subscript and slice#

-- Access by index (0-based)
RETURN n.tags[0]          -- first element
RETURN n.tags[$idx]       -- dynamic index via parameter
 
-- Slice
RETURN n.tags[1..3]       -- elements at index 1 and 2
RETURN n.tags[..3]        -- first 3 elements
RETURN n.tags[-2..]       -- last 2 elements

List comprehension#

-- [variable IN list WHERE filter | transform]
MATCH (n:Person)
RETURN [x IN n.scores WHERE x > 80 | x * 1.1] AS bonus_scores
 
-- filter only
RETURN [x IN n.tags WHERE x <> 'archived'] AS active_tags
 
-- transform only
RETURN [x IN range(1, 10) | x * x] AS squares

List quantifiers#

WHERE ALL(x IN n.scores WHERE x > 60)     -- all elements match
WHERE ANY(x IN n.tags WHERE x = 'urgent') -- at least one matches
WHERE NONE(x IN n.tags WHERE x = 'spam')  -- none match

Built-in Functions

This reference is designed for both human developers and AI coding agents. Every entry includes complete syntax that can be used directly in queries.

Aggregation (11)#

Aggregation functions operate across rows in a result set. Use with or without GROUP BY (via WITH).

Function	Syntax	Description	Return Type	Since
`count`	`count(expr)`	Number of non-null values	Integer	0.4.0
`count(DISTINCT)`	`count(DISTINCT expr)`	Number of distinct non-null values	Integer	0.4.0
`sum`	`sum(expr)`	Sum of numeric values	Float	0.4.0
`avg`	`avg(expr)`	Arithmetic mean	Float	0.4.0
`min`	`min(expr)`	Minimum value	Same as input	0.4.0
`max`	`max(expr)`	Maximum value	Same as input	0.4.0
`collect`	`collect(expr)`	Collect values into a list	List	0.4.0
`percentile`	`percentile(expr, p)`	Percentile value (p between 0.0 and 1.0)	Float	4.0.0
`stdev`	`stdev(expr)`	Sample standard deviation	Float	4.0.0
`variance`	`variance(expr)`	Sample variance	Float	4.0.0
`median`	`median(expr)`	Median (50th percentile)	Float	4.0.0

MATCH (n:Person)
RETURN count(n) AS total, avg(n.age) AS avgAge, percentile(n.score, 0.95) AS p95

MATCH (n:Person)
WITH n.department AS dept, collect(n.name) AS members, stdev(n.salary) AS salaryStdev
RETURN dept, members, salaryStdev

String (23)#

Function	Syntax	Description	Return Type	Since
`toLower`	`toLower(s)`	Convert to lowercase	String	0.17.0
`toUpper`	`toUpper(s)`	Convert to uppercase	String	0.17.0
`trim`	`trim(s)`	Strip leading and trailing whitespace	String	0.17.0
`ltrim`	`ltrim(s)`	Strip leading whitespace	String	4.0.0
`rtrim`	`rtrim(s)`	Strip trailing whitespace	String	4.0.0
`substring`	`substring(s, start, len)`	Extract substring from start position	String	0.17.0
`left`	`left(s, n)`	First n characters	String	0.17.0
`right`	`right(s, n)`	Last n characters	String	0.17.0
`head`	`head(expr)`	First element of a list or comma-separated string	Same as element	3.0.0
`last`	`last(expr)`	Last element of a list or comma-separated string	Same as element	3.0.0
`replace`	`replace(s, find, rep)`	Replace all occurrences of find with rep	String	0.17.0
`split`	`split(s, delim)`	Split string by delimiter into list	List	0.17.0
`reverse`	`reverse(s)`	Reverse a string or comma-separated list	String	0.17.0
`sort`	`sort(expr)`	Alphabetically sort comma-separated string values	String	4.0.0
`repeat`	`repeat(s, n)`	Repeat string n times	String	4.0.0
`lpad`	`lpad(s, width, char)`	Left-pad string to width with char	String	4.0.0
`rpad`	`rpad(s, width, char)`	Right-pad string to width with char	String	4.0.0
`contains`	`contains(s, sub)`	True if string contains substring	Boolean	4.0.0
`startsWith`	`startsWith(s, prefix)`	True if string starts with prefix	Boolean	4.0.0
`endsWith`	`endsWith(s, suffix)`	True if string ends with suffix	Boolean	4.0.0
`indexOf`	`indexOf(s, sub)`	Position of substring, -1 if not found	Integer	4.0.0
`size`	`size(s)`	Length of string or list	Integer	0.10.0
`toString`	`toString(expr)`	Convert any value to string representation	String	0.10.0

MATCH (n:Person)
RETURN toLower(n.name) AS lower, left(n.name, 3) AS initials, size(n.name) AS len

MATCH (n:Person)
WHERE startsWith(n.email, 'admin')
RETURN n.name, replace(n.email, '@old.com', '@new.com') AS newEmail

MATCH (n:Person)
RETURN lpad(toString(n.id), 6, '0') AS paddedId, repeat('*', n.rating) AS stars

Math (17)#

Function	Syntax	Description	Return Type	Since
`abs`	`abs(expr)`	Absolute value	Float	4.0.0
`round`	`round(expr)`	Round to nearest integer	Float	4.0.0
`ceil`	`ceil(expr)`	Ceiling (round up)	Float	4.0.0
`floor`	`floor(expr)`	Floor (round down)	Float	4.0.0
`sqrt`	`sqrt(expr)`	Square root	Float	4.0.0
`sign`	`sign(expr)`	Signum: -1, 0, or 1	Float	4.0.0
`exp`	`exp(expr)`	e raised to the power of the value	Float	4.0.0
`log`	`log(expr)`	Natural logarithm (ln)	Float	4.0.0
`log10`	`log10(expr)`	Base-10 logarithm	Float	10.0.0
`log2`	`log2(expr)`	Base-2 logarithm	Float	10.0.0
`power`	`power(base, exp)`	Raise base to exponent	Float	4.0.0
`sin`	`sin(expr)`	Sine (radians)	Float	4.0.0
`cos`	`cos(expr)`	Cosine (radians)	Float	4.0.0
`tan`	`tan(expr)`	Tangent (radians)	Float	4.0.0
`atan2`	`atan2(y, x)`	Arctangent of y/x (radians)	Float	4.0.0
`pi`	`pi()`	Pi constant (3.14159...)	Float	4.0.0
`e`	`e()`	Euler's number (2.71828...)	Float	4.0.0

MATCH (n:Sensor)
RETURN n.name, abs(n.reading) AS magnitude, round(n.value * 100) / 100 AS rounded

MATCH (n:Point)
RETURN atan2(n.y, n.x) AS angle, sqrt(power(n.x, 2) + power(n.y, 2)) AS distance

Type Conversion (5)#

Function	Syntax	Description	Return Type	Since
`toString`	`toString(expr)`	Convert to string	String	0.10.0
`toInteger`	`toInteger(expr)`	Convert to integer	Integer	0.10.0
`toFloat`	`toFloat(expr)`	Convert to float	Float	0.10.0
`toBoolean`	`toBoolean(expr)`	Convert to boolean	Boolean	4.0.0
`coalesce`	`coalesce(a, b, ...)`	First non-null value	Same as first non-null	0.10.0

MATCH (n:Person)
RETURN toInteger(n.ageStr) AS age, coalesce(n.nickname, n.name) AS displayName

Graph Introspection (6)#

Function	Syntax	Description	Return Type	Since
`id`	`id(n)`	Internal node or relationship ID	Integer	0.8.0
`labels`	`labels(n)`	List of labels on a node	List<String>	0.8.0
`type`	`type(r)`	Relationship type string	String	0.8.0
`degree`	`degree(n)`	Total degree (in + out)	Integer	3.0.0
`inDegree`	`inDegree(n)`	Incoming relationship count	Integer	3.0.0
`outDegree`	`outDegree(n)`	Outgoing relationship count	Integer	3.0.0

MATCH (n:Person)
RETURN n.name, degree(n) AS connections, inDegree(n) AS followers, outDegree(n) AS following
ORDER BY degree(n) DESC

Node Metadata (5)#

ArcFlow world-model metadata functions for provenance and trust scoring.

Function	Syntax	Description	Return Type	Since
`confidence`	`confidence(n)`	World-model confidence score (0.0-1.0)	Float	4.0.0
`observationClass`	`observationClass(n)`	Observation class: observed, inferred, or predicted	String	4.0.0
`authorityPlane`	`authorityPlane(n)`	Authority plane: semantic or scene	String	4.0.0
`clockDomain`	`clockDomain(n)`	Temporal clock domain name	String	4.0.0
`observationSource`	`observationSource(n)`	Source identity (sensor, model, user)	String	4.0.0

MATCH (n:Observation)
WHERE confidence(n) > 0.8 AND observationClass(n) = 'observed'
RETURN n.name, confidence(n) AS conf, authorityPlane(n) AS plane

Map and List (4)#

Function	Syntax	Description	Return Type	Since
`properties`	`properties(n)`	Full property map as string	String	4.0.0
`keys`	`keys(n)`	List of property key names	List<String>	3.0.0
`range`	`range(start, end)`	Generate integer sequence [start..=end]	List<Integer>	4.0.0
`mapProjection`	`n {.name, .age}`	Return only named properties as a map	Map	4.0.0

MATCH (n:Person)
RETURN keys(n) AS propKeys, properties(n) AS allProps

MATCH (n:Person)
RETURN n {.name, .age} AS profile

UNWIND range(1, 10) AS i
RETURN i

Date/Time (4)#

All date/time functions are non-deterministic (they return the current time).

Function	Syntax	Description	Return Type	Since
`timestamp`	`timestamp()`	Current Unix timestamp in milliseconds	Integer	4.0.0
`date`	`date()`	Current date as ISO string (YYYY-MM-DD)	String	4.0.0
`time`	`time()`	Current time as ISO string (HH:MM:SS.mmm)	String	4.0.0
`datetime`	`datetime()`	Current datetime as ISO string (YYYY-MM-DDTHH:MM:SS.mmm)	String	4.0.0

CREATE (e:Event {name: 'deploy', createdAt: timestamp(), date: date()})
RETURN e

Utility (4)#

Function	Syntax	Description	Return Type	Since
`randomUUID`	`randomUUID()`	Generate a UUID v4 string	String	4.0.0
`hash`	`hash(expr)`	Deterministic FNV-1a 64-bit hash as hex string	String	4.0.0
`toJson`	`toJson(n)`	Serialize all node properties to JSON string	String	4.0.0
`size`	`size(expr)`	Length of string or list	Integer	0.10.0

CREATE (n:Record {id: randomUUID(), fingerprint: hash(n.data)})
RETURN n

MATCH (n:Person)
RETURN toJson(n) AS json

Predicates (4)#

Predicate expressions used in WHERE clauses and RETURN.

Predicate	Syntax	Description	Return Type	Since
`exists`	`exists(n.prop)`	True if property exists	Boolean	0.6.0
`IS NULL`	`n.prop IS NULL`	True if property is null or missing	Boolean	0.15.0
`IS NOT NULL`	`n.prop IS NOT NULL`	True if property exists and is not null	Boolean	0.15.0
`IN`	`expr IN [list]`	True if value is in the list	Boolean	0.20.0

MATCH (n:Person)
WHERE exists(n.email) AND n.role IN ['admin', 'editor']
RETURN n.name

MATCH (n:Person)
WHERE n.deletedAt IS NULL
RETURN n.name

Path Functions (3)#

Functions for operating on path values bound with MATCH p = ....

Function	Syntax	Description	Return Type
`nodes`	`nodes(path)`	Ordered list of nodes along the path	List<Node>
`relationships`	`relationships(path)`	Ordered list of relationships along the path	List<Rel>
`length`	`length(path)`	Number of relationships in the path	Integer

MATCH p = (a:Person {name: 'Alice'})-[*..5]->(b:Person {name: 'Dave'})
RETURN length(p) AS hops, [n IN nodes(p) | n.name] AS names

List Operations#

List subscript and slice#

-- Access by index (0-based)
RETURN n.tags[0]          -- first element
RETURN n.tags[$idx]       -- dynamic index via parameter
 
-- Slice
RETURN n.tags[1..3]       -- elements at index 1 and 2
RETURN n.tags[..3]        -- first 3 elements
RETURN n.tags[-2..]       -- last 2 elements

List comprehension#

-- [variable IN list WHERE filter | transform]
MATCH (n:Person)
RETURN [x IN n.scores WHERE x > 80 | x * 1.1] AS bonus_scores
 
-- filter only
RETURN [x IN n.tags WHERE x <> 'archived'] AS active_tags
 
-- transform only
RETURN [x IN range(1, 10) | x * x] AS squares

List quantifiers#

WHERE ALL(x IN n.scores WHERE x > 60)     -- all elements match
WHERE ANY(x IN n.tags WHERE x = 'urgent') -- at least one matches
WHERE NONE(x IN n.tags WHERE x = 'spam')  -- none match

Built-in Functions

Aggregation (11)#

String (23)#

Math (17)#

Type Conversion (5)#

Graph Introspection (6)#

Node Metadata (5)#

Map and List (4)#

Date/Time (4)#

Utility (4)#

Predicates (4)#

Path Functions (3)#

List Operations#

List subscript and slice#

List comprehension#

List quantifiers#

See Also#

Built-in Functions

Aggregation (11)#

String (23)#

Math (17)#

Type Conversion (5)#

Graph Introspection (6)#

Node Metadata (5)#

Map and List (4)#

Date/Time (4)#

Utility (4)#

Predicates (4)#

Path Functions (3)#

List Operations#

List subscript and slice#

List comprehension#

List quantifiers#

See Also#