Generate IDs

The CLI provides commands to generate IDs using all supported generators. Each generator has specific options for customization.

Basic Usage

Generate a single ID using shorthand syntax:

uniku uuid    # UUID v4 (default)
uniku ulid    # ULID
uniku nanoid  # Nanoid
uniku cuid    # CUID2
uniku ksuid   # KSUID

Or use the explicit generate command:

uniku generate uuid
uniku generate ulid

UUID Generation

Generate UUIDs (version 4 or 7):

# UUID v4 (random, default)
uniku uuid
# => 550e8400-e29b-41d4-a716-446655440000

# UUID v7 (time-ordered)
uniku uuid --version 7
# => 018e5e5c-7c8a-7000-8000-000000000000

UUID Options

--version

4 | 7

default:"4"

UUID version to generate. Alias: -v

4 — Random UUID (RFC 4122)
7 — Time-ordered UUID with millisecond precision (RFC 9562)

uniku uuid --version 7

--lowercase

boolean

default:"false"

Output in lowercase instead of uppercase. Alias: -l

uniku uuid --lowercase
# => 550e8400-e29b-41d4-a716-446655440000

--count

number

default:"1"

Number of UUIDs to generate. Alias: -n

uniku uuid --count 5

uniku uuid --count 3
550e8400-e29b-41d4-a716-446655440000
6ba7b810-9dad-11d1-80b4-00c04fd430c8
7c9e6679-7425-40de-944b-e07fc1f90ae7

UUID v7 embeds a timestamp and is sortable, making it ideal for database primary keys and distributed systems.

ULID Generation

Generate Universally Unique Lexicographically Sortable Identifiers:

# Standard ULID
uniku ulid
# => 01HW9T2W9W9YJ3JZ1H4P4M2T8Q

# Monotonically increasing ULIDs
uniku ulid --monotonic --count 3

ULID Options

--monotonic

boolean

default:"false"

Generate monotonically increasing ULIDs with the same timestamp

uniku ulid --monotonic --count 5

Guarantees that each successive ULID is lexicographically greater, even if generated within the same millisecond.

--timestamp

string

Unix timestamp in milliseconds or "now"

uniku ulid --timestamp 1704067200000
uniku ulid --timestamp now

--lowercase

boolean

default:"false"

Output in lowercase. Alias: -l

uniku ulid --lowercase
# => 01hw9t2w9w9yj3jz1h4p4m2t8q

uniku ulid --count 3
01HW9T2W9W9YJ3JZ1H4P4M2T8Q
01HW9T2W9XABCDEFGHIJKLMNOP
01HW9T2W9YZYXWVUTSRQPONMLK

Use --monotonic when generating multiple ULIDs in rapid succession to guarantee sort order.

Nanoid Generation

Generate compact, URL-safe unique identifiers:

# Default 21-character Nanoid
uniku nanoid
# => V1StGXR8_Z5jdHi6B-myT

# Custom size
uniku nanoid --size 12
# => V1StGXR8_Z5j

Nanoid Options

--size

number

default:"21"

Length of the generated ID (1-256). Alias: -s

uniku nanoid --size 32

--alphabet

string

Custom alphabet or preset name. Alias: -aPresets:

hex — Hexadecimal (0-9, a-f)
numeric — Numbers only (0-9)
alpha — Letters only (a-z, A-Z)

Custom alphabet:

uniku nanoid --alphabet "0123456789ABCDEF"

uniku nanoid --count 3
V1StGXR8_Z5jdHi6B-myT
K3fG9mN2pQwE7rY8sX6cH
L9jT4vR2xD8aW5nB3kM6p

Shorter IDs have higher collision probability. Use at least 21 characters for production systems.

CUID2 Generation

Generate collision-resistant, secure identifiers:

# Default 24-character CUID2
uniku cuid
# => clhw9t2w9w9yj3jz1h4p4m2t

# Custom length
uniku cuid --length 16

CUID2 Options

--length

number

default:"24"

Length of the generated ID (2-32). Alias: -l

uniku cuid --length 32

uniku cuid --count 3
clhw9t2w9w9yj3jz1h4p4m2t
clhw9t2w9xabcdefghijklmn
clhw9t2w9yzyxwvutsrqponm

CUID2 is designed to be collision-resistant even without coordination. It’s ideal for distributed systems where UUIDs feel too long.

KSUID Generation

Generate K-Sortable Unique Identifiers:

# Standard KSUID
uniku ksuid
# => 2HbcvN9VFGzP8jR5mK3QxW4d

# Custom timestamp
uniku ksuid --timestamp 1704067200

KSUID Options

--timestamp

string

Unix timestamp in seconds or "now"

uniku ksuid --timestamp 1704067200
uniku ksuid --timestamp now

uniku ksuid --count 3
2HbcvN9VFGzP8jR5mK3QxW4d
2HbcvN9VFH1Q9kS6nL4RyX5e
2HbcvN9VFH2R0lT7oM5SzY6f

KSUIDs encode timestamps with second precision (vs. millisecond for ULIDs), making them slightly more compact.

JSON Output

All generation commands support --json for structured output:

uniku uuid --count 3 --json

[
  {"id":"550e8400-e29b-41d4-a716-446655440000"},
  {"id":"6ba7b810-9dad-11d1-80b4-00c04fd430c8"},
  {"id":"7c9e6679-7425-40de-944b-e07fc1f90ae7"}
]

This is useful for scripting and programmatic consumption:

# Extract IDs using jq
uniku uuid --count 5 --json | jq -r '.[].id'

# Store in a variable
ID=$(uniku uuid --json | jq -r '.id')
echo "Generated ID: $ID"

Comparison Table

Generator	Default Length	Time-Ordered	Monotonic	URL-Safe
UUID v4	36 chars	No	No	No
UUID v7	36 chars	Yes (ms)	Yes	No
ULID	26 chars	Yes (ms)	Optional	Yes
Nanoid	21 chars	No	No	Yes
CUID2	24 chars	No	No	Yes
KSUID	27 chars	Yes (sec)	Yes	Yes

CLI Tool

Generate IDs

Basic Usage

UUID Generation

UUID Options

ULID Generation

ULID Options

Nanoid Generation

Nanoid Options

CUID2 Generation

CUID2 Options

KSUID Generation

KSUID Options

JSON Output

Comparison Table

Next Steps

Validate IDs

Inspect IDs

Build docs developers (and LLMs) love

CLI Tool

​Basic Usage

​UUID Generation

​UUID Options

​ULID Generation

​ULID Options

​Nanoid Generation

​Nanoid Options

​CUID2 Generation

​CUID2 Options

​KSUID Generation

​KSUID Options

​JSON Output

​Comparison Table

​Next Steps

Validate IDs

Inspect IDs

Build docs developers (and LLMs) love

Basic Usage

UUID Generation

UUID Options

ULID Generation

ULID Options

Nanoid Generation

Nanoid Options

CUID2 Generation

CUID2 Options

KSUID Generation

KSUID Options

JSON Output

Comparison Table

Next Steps