# facebook/FBRetainCycleDetector

iOS library to help detecting retain cycles in runtime.

Repository: https://github.com/facebook/FBRetainCycleDetector
Canonical: https://ross.abutalabs.com/products/fbretaincycledetector
Language: Objective-C++
License: NOASSERTION
License Family: other
Last push: 2026-08-19T23:28:07+00:00

## Health v2 (maintenance only)
Score: 67/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 8, longevity 100
- inputs: {"age_days": 3800, "days_push": 14, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4232, forks 601 (observed 2026-08-28T04:08:39.464566+00:00)

## What it is
An iOS library by Facebook that detects retain cycles causing memory leaks through runtime analysis of object graphs. It inspects objects at runtime and reports cycles as sets of object reference chains.

## Use cases
- find memory leaks caused by retain cycles in an iOS app
- detect circular strong references between Objective-C objects at runtime
- debug memory issues in debug builds of an iOS project
- audit objects for reference cycles during development
- integrate retain cycle detection into a debugging or QA workflow

## When to avoid
- you need memory leak detection on Android or non-Apple platforms
- you require production-build analysis, since it only works fully in Debug builds
- you need Swift-only tooling with modern Swift concurrency support

## Facets
- artifact type: library
- maturity: maintenance
- function: monitoring, developer-tools, testing
- domain: mobile-development, developer-tools, performance
- platform: cross-platform
- tags: memory-leaks, retain-cycles, objective-c, runtime-analysis, debugging, ios, mobile

## Member repositories
- facebook/FBRetainCycleDetector (main) score 67

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:39.464566+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 2026-08-29T18:22:20.301129+00:00, confidence not recorded.
  - readme: https://github.com/facebook/FBRetainCycleDetector (fetched 2026-08-28T04:08:39.464566+00:00, sha 4b5560dcb830)
- Data as of 2026-08-30T08:39:29.467469+00:00.