# couchbase/forestdb

A Fast Key-Value Storage Engine Based on Hierarchical B+-Tree Trie

Repository: https://github.com/couchbase/forestdb
Canonical: https://ross.abutalabs.com/products/forestdb
Language: C++
License: Apache-2.0
License Family: permissive
Last push: 2025-11-21T02:49:38+00:00

## Health v2 (maintenance only)
Score: 56/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 53, release rhythm 35, longevity 100
- inputs: {"age_days": 4751, "days_push": 285, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1333, forks 178 (observed 2026-08-28T04:04:24.569096+00:00)

## What it is
ForestDB is an embedded key-value storage engine written in C/C++ by Couchbase, using a Hierarchical B+-Tree based Trie (HB+-Trie) as its main index structure. It provides MVCC, snapshots, transactions, WAL, and compaction, and was used in Couchbase Server and Couchbase Lite.

## Use cases
- embed a fast key-value storage engine in a C/C++ application
- store binary keys and values with custom key ordering
- build a local database with MVCC and snapshot support
- run a storage engine on mobile devices like iOS and Android
- benchmark alternative key-value storage engines
- implement transactional local persistence with rollback support

## When to choose
- you need an embedded, linkable key-value store in C or C++
- your workload has long or binary keys where trie-based indexing outperforms B+-Tree engines
- you need MVCC, snapshots, and ranged iteration in a local store
- you target cross-platform deployment including mobile OSes

## When to avoid
- you need an actively developed engine with ongoing community support
- you want a client-server database rather than an embedded library
- your project depends on Couchbase Server 6.0+ where ForestDB was superseded
- you prefer higher-level language bindings or managed storage

## Facets
- artifact type: library
- maturity: maintenance
- function: database, caching, serialization
- domain: databases, developer-tools, mobile-development
- platform: windows, cpp, c
- tags: key-value-store, storage-engine, b-plus-tree, mvcc, append-only, embedded-database, write-ahead-logging, linux, macos, android, ios

## Member repositories
- couchbase/forestdb (main) score 56

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:24.569096+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 2026-08-30T04:44:42.221764+00:00, confidence not recorded.
  - readme: https://github.com/couchbase/forestdb (fetched 2026-08-28T04:04:24.569096+00:00, sha 54c4af580da2)
- Data as of 2026-08-30T08:39:29.467469+00:00.