sparkid 1.3.1

Fast, time-sortable, 21-char Base58 unique ID generator

sparkid

Fast, monotonic, time-sortable, 21-char Base58 unique ID generator. Zero dependencies.

1ocmpHE1bFnygEBAPTzMK
1ocmpHE1bFnygFv4Wp4dL
1ocmpHE1bFnygGoUXUL7X

Install

pip install sparkid

Usage

from sparkid import generate_id

id = generate_id()
# => "1ocmpHE1bFnygEBAPTzMK"

Properties

Property	Value
Length	21 characters, fixed
Alphabet	Base58 (no 0, O, I, l)
Sortable	Lexicographically, by creation time
Monotonic	Strictly increasing within each thread
URL-safe	Yes
Collision resistance	~58^13 (~8.4 x 10^22) combinations per millisecond
Randomness	Cryptographically secure (os.urandom)
Thread-safe	Yes (via threading.local)

How it works

Each ID is composed of two parts:

[8-char timestamp][13-char suffix]

• Timestamp (8 chars): Current time in milliseconds, Base58-encoded. IDs generated in a later millisecond always sort after earlier ones.
• Suffix (13 chars): Seeded from os.urandom (rejection-sampled, no modulo bias) at the start of each millisecond, then monotonically incremented for each subsequent ID within that millisecond. This guarantees strict ordering even when multiple IDs share a timestamp.

Ordering guarantees

IDs from a single IdGenerator instance (or a single thread using generate_id()) are strictly monotonically increasing — every ID is lexicographically greater than the one before it.

Across threads, IDs are unique but not ordered relative to each other. Each thread gets its own generator via threading.local, so there is no cross-thread coordination. This is the same guarantee provided by most UUID v7 libraries.

If you need process-wide monotonic ordering across threads, wrap a single IdGenerator in a lock:

import threading
from sparkid import IdGenerator

_lock = threading.Lock()
_gen = IdGenerator()

def generate_id_monotonic():
    with _lock:
        return _gen()

Advanced usage

For manual control, use the IdGenerator class directly:

from sparkid import IdGenerator

gen = IdGenerator()
id = gen()

Each IdGenerator instance maintains its own internal state. The module-level generate_id() function uses threading.local to automatically create one instance per thread.

Performance

python bench/benchmark.py

License

MIT