uuider

A command-line tool for generating UUIDs (v4 and v7) with fine-grained control over their components.

Features

Generate random UUIDv4 and UUIDv7
Create deterministic UUIDs from hex constants
Control UUIDv7 timestamps precisely
Set random portions to min/max values for range queries

Installation

From Source

Requires Rust 1.85 or later.

# Clone the repository
git clone https://github.com/yourusername/uuider.git
cd uuider

# Install globally
cargo install --path .

The binary will be installed to ~/.cargo/bin/uuider. Make sure this directory is in your PATH.

Usage

UUIDv4

Generate a random UUIDv4:

uuider v4
# Output: 550e8400-e29b-41d4-a716-446655440000

Generate a UUIDv4 from a hex constant (up to 122 bits):

uuider v4 --from-hex 1
# Output: 00000000-0000-4000-8000-000000000001

uuider v4 --from-hex 0xdeadbeef
# Output: 00000000-0000-4000-8000-0000deadbeef

UUIDv7

Generate a UUIDv7 with the current timestamp:

uuider v7
# Output: 019c6287-bdcc-7a3f-8b2d-4e5f6a7b8c9d

Generate a UUIDv7 with a specific timestamp (milliseconds since Unix epoch):

uuider v7 --time 1700000000000
# Output: 018b8f5a-8c00-7a3f-8b2d-4e5f6a7b8c9d

Generate a UUIDv7 with minimum random bits (useful for range query lower bounds):

uuider v7 --min
# Output: 019c6287-bdcc-7000-8000-000000000000

uuider v7 --time 0 --min
# Output: 00000000-0000-7000-8000-000000000000

Generate a UUIDv7 with maximum random bits (useful for range query upper bounds):

uuider v7 --max
# Output: 019c6287-bdcc-7fff-bfff-ffffffffffff

uuider v7 --time 0 --max
# Output: 00000000-0000-7fff-bfff-ffffffffffff

Generate a UUIDv7 with a specific hex constant for the random portion (up to 74 bits):

uuider v7 --from-hex abc123
# Output: 019c6287-bdcc-7000-8000-000000abc123

Options Reference

`uuider v4`

| Option | Description | |--------|-------------| | --from-hex <HEX> | Use a hex constant (up to 122 bits) instead of random data |

`uuider v7`

| Option | Description | |--------|-------------| | --time <MILLIS> | Unix timestamp in milliseconds (defaults to current time) | | --from-hex <HEX> | Use a hex constant (up to 74 bits) for the random portion | | --min | Set all random bits to 0 | | --max | Set all random bits to 1 |

Note: --from-hex, --min, and --max are mutually exclusive.

UUID Structure

UUIDv4 (RFC 4122)

xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
             │    │
             │    └── Variant (2 bits): 10
             └─────── Version (4 bits): 0100

122 bits of random/constant data
4-bit version field (always 4)
2-bit variant field (always 10)

UUIDv7 (RFC 9562)

tttttttt-tttt-7xxx-yxxx-xxxxxxxxxxxx
│             │    │
│             │    └── Variant (2 bits): 10
│             └─────── Version (4 bits): 0111
└──────────────────── Timestamp (48 bits)

48-bit Unix timestamp in milliseconds
4-bit version field (always 7)
12-bit random field (rand_a)
2-bit variant field (always 10)
62-bit random field (rand_b)

License

MIT

Uuider

Install / Use

README