# Cysharp/Ulid

Fast .NET C# Implementation of ULID for .NET and Unity.

Repository: https://github.com/Cysharp/Ulid
Canonical: https://ross.abutalabs.com/products/cysharp-ulid
Language: C#
License: MIT
License Family: permissive
Last push: 2026-07-08T03:24:21+00:00

## Health v2 (maintenance only)
Score: 75/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 91, release rhythm 40, longevity 100
- inputs: {"age_days": 2716, "days_push": 56, "days_rel": 402, "gap_med": 1.0, "n_releases_24m": 3}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1646, forks 71 (observed 2026-08-28T04:05:16.290383+00:00)

## What it is
A fast C# implementation of ULID (Universally Unique Lexicographically Sortable Identifier) for .NET and Unity. It generates sortable random IDs faster than Guid.NewGuid with zero-allocation parsing and serialization.

## Use cases
- generate sortable unique ids in .net
- fast ulid generation for c#
- replace guid with sortable identifiers
- generate ulids in unity
- high-performance id parsing without allocations
- lexicographically sortable random ids for database keys

## When to choose
- you need time-sortable unique identifiers in .NET or Unity
- performance matters and you want faster-than-Guid generation with zero allocations
- you want Guid interop and a familiar API

## When to avoid
- you only need standard GUIDs with no sorting requirement
- you are not on a .NET or Unity platform

## Facets
- artifact type: library
- maturity: active
- function: serialization, developer-tools
- domain: developer-tools, databases, backend
- platform: dotnet, cross-platform
- tags: ulid, unique-ids, csharp, unity, sortable-ids, identifier-generation

## Member repositories
- Cysharp/Ulid (main) score 75

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:16.290383+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:45:21.858962+00:00, confidence not recorded.
  - readme: https://github.com/Cysharp/Ulid (fetched 2026-08-28T04:05:16.290383+00:00, sha 29bd0e3926d2)
- Data as of 2026-08-30T08:39:29.467469+00:00.