Built-in Transforms

Built-in transforms are implemented in Go and registered when Prelude Collector starts. They are available to every data model without any additional configuration. After this first mention, the rest of this page refers to Prelude Collector as "the collector".

The Name column is the string you put in the transforms list of a field mapping. Every function takes a single value and returns a single value.

---

strings

General-purpose string operations.

Name	Input	Output	Description	Example
trim_whitespace	string	string	Removes leading and trailing whitespace.	" hello " → "hello"
lowercase	string	string	Converts to lowercase.	"HELLO" → "hello"
uppercase	string	string	Converts to uppercase.	"hello" → "HELLO"
hex_to_int	string	int64	Parses a hex string (with or without 0x prefix) to an integer.	"0x1f" → 31
int_to_hex	numeric	string	Formats an integer as a lowercase hex string with 0x prefix.	31 → "0x1f"
base64_decode	string	string	Decodes a Base64-encoded string.	"aGVsbG8=" → "hello"
truncate_256	string	string	Truncates a string to 256 characters; non-strings pass through unchanged.	a 300-char string → its first 256 chars

---

time

Timestamp and duration conversions.

Name	Input	Output	Description	Example
unix_to_iso	numeric / string	string	Converts a Unix timestamp (seconds since epoch) to RFC 3339 / ISO 8601.	1700000000 → "2023-11-14T22:13:20Z"
unix_ms_to_iso	numeric / string	string	Converts a Unix timestamp in milliseconds to RFC 3339 / ISO 8601.	1700000000000 → "2023-11-14T22:13:20Z"
seconds_to_duration	numeric / string	string	Converts a duration in seconds to a human-readable string.	90061 → "1d 1h 1m 1s"

---

ip

IP address and subnet operations.

Name	Input	Output	Description	Example
ip_with_prefix	numeric / 4-byte bytes / dotted-quad string	string	Converts a packed 32-bit IPv4 address to dotted-quad notation. Accepts any signed/unsigned integer width, a 4-byte bytes value, or a string that is either dotted-quad text or 4 raw bytes.	0xC0000201 → "192.0.2.1"
ip_with_netmask	numeric / 4-byte bytes / string	string	Converts a packed 32-bit subnet mask to prefix-length notation. Accepts the same input shapes as ip_with_prefix.	0xFFFFFF00 → "/24"
netmask_to_prefix	string	int	Converts a dotted-quad subnet mask to an integer prefix length.	"255.255.255.0" → 24
ipv6_compress	string	string	Parses an IPv6 address and returns its compressed form.	"2001:0db8:0000:0000:0000:0000:0000:0001" → "2001:db8::1"
ipv6_expand	string	string	Parses an IPv6 address and returns its fully expanded form (8 groups of 4 hex).	"2001:db8::1" → "2001:0db8:0000:0000:0000:0000:0000:0001"
mac_to_eui48	string	string	Normalises any MAC format (:, -, or Cisco .) to lowercase EUI-48 notation.	"AABB.CCDD.EEFF" → "aa:bb:cc:dd:ee:ff"

---

bgp

BGP-specific format conversions.

Name	Input	Output	Description	Example
as_plain	string / numeric	string / numeric	Converts an ASN from asdot+ notation ("X.Y") to plain decimal. Integer inputs and plain-decimal strings (no dot) pass through unchanged.	"1.0" → "65536"
as_dot	numeric / string	string	Converts an ASN integer to asdot+ notation.	65536 → "1.0"
bgp_community	numeric / string	string	Formats a uint32 as a BGP standard community string HI:LO.	131072 → "2:0"
bgp_ext_community	numeric / string	string	Formats a uint64 as a BGP extended community string TYPE:HI:LO.	0x0002000100000064 → "2:1:100"

---

snmp

SNMP-specific type conversions.

Name	Input	Output	Description	Example
timeticks_to_seconds	numeric	float64	Converts SNMP TimeTicks (1/100 seconds) to seconds.	36000 → 360.0
timeticks_to_uptime	numeric	string	Converts SNMP TimeTicks to a human-readable uptime string.	360000 → "0d 1h 0m 0s"
octetstring_to_hex	bytes / string	string	Converts raw bytes to a colon-separated lowercase hex string.	\xaa\xbb → "aa:bb"
octetstring_to_mac	bytes / string (6 bytes)	string	Converts a 6-byte octet string to a MAC address.	\xaa\xbb\xcc\xdd\xee\xff → "aa:bb:cc:dd:ee:ff"
strip_null_bytes	string	string	Removes null bytes (\x00) from a string.	"hello\x00" → "hello"
oid_last_segment	string	string	Returns everything after the last dot in an OID string.	"1.3.6.1.2.1.1.5.0" → "0"

---

units

Numeric unit conversions. All functions accept any numeric type or a numeric string.

Name	Input	Output	Description	Example
speed_to_human	numeric	string	Converts a raw bps value to a human-readable string with SI suffix.	1000000000 → "1G", 1000 → "1K"
mul_8	numeric	float64	Multiplies by 8 — bytes-to-bits conversion.	125000000 → 1000000000.0
to_mbps	numeric	float64	Divides by 1,000,000 — converts bps to Mbps.	1000000000 → 1000.0
to_gbps	numeric	float64	Divides by 1,000,000,000 — converts bps to Gbps.	1000000000 → 1.0
bytes_to_mb	numeric	float64	Converts bytes to megabytes (÷ 1,048,576).	1048576 → 1.0
bytes_to_gb	numeric	float64	Converts bytes to gigabytes (÷ 1,073,741,824).	1073741824 → 1.0
div_10	numeric	float64	Divides by 10.	100 → 10.0
div_100	numeric	float64	Divides by 100.	100 → 1.0
div_1000	numeric	float64	Divides by 1000 — milli-units to units.	1000 → 1.0
celsius_to_fahrenheit	numeric	float64	Converts Celsius to Fahrenheit.	100 → 212.0

---

enum

Maps integer MIB codes to human-readable string names. All functions accept any numeric type or a numeric string.

Interface (IF-MIB)

Name	Input	Output	Description	Mapping
if_admin_status	numeric	string	Maps IF-MIB ifAdminStatus integer to name.	1=up, 2=down, 3=testing
if_oper_status	numeric	string	Maps IF-MIB ifOperStatus integer to name.	1=up, 2=down, 3=testing, 4=unknown, 5=dormant, 6=notPresent, 7=lowerLayerDown

BGP (RFC 4271)

Name	Input	Output	Description	Mapping
bgp_state	numeric	string	Maps the BGP FSM state integer to its name.	1=Idle, 2=Connect, 3=Active, 4=OpenSent, 5=OpenConfirm, 6=Established

IS-IS (ISIS-MIB)

Name	Input	Output	Description	Mapping
isis_adj_state	numeric	string	Maps ISIS-MIB isisISAdjState to name.	1=down, 2=initializing, 3=up

OSPF (OSPF-MIB)

Name	Input	Output	Description	Mapping
ospf_neighbor_state	numeric	string	Maps OSPF-MIB ospfNbrState to name.	1=Down, 2=Attempt, 3=Init, 4=2-Way, 5=ExStart, 6=Exchange, 7=Loading, 8=Full

---

Quick reference

Module	Transform names
strings	trim_whitespace, lowercase, uppercase, hex_to_int, int_to_hex, base64_decode, truncate_256
time	unix_to_iso, unix_ms_to_iso, seconds_to_duration
ip	ip_with_prefix, ip_with_netmask, netmask_to_prefix, ipv6_compress, ipv6_expand, mac_to_eui48
bgp	as_plain, as_dot, bgp_community, bgp_ext_community
snmp	timeticks_to_seconds, timeticks_to_uptime, octetstring_to_hex, octetstring_to_mac, strip_null_bytes, oid_last_segment
units	speed_to_human, mul_8, to_mbps, to_gbps, bytes_to_mb, bytes_to_gb, div_10, div_100, div_1000, celsius_to_fahrenheit
enum	if_admin_status, if_oper_status, bgp_state, isis_adj_state, ospf_neighbor_state

See also

• Transforms overview
• Custom transforms
• Fields & Mappings
• API reference