# gorules/zen

Open-source Business Rules Engine for your Rust, NodeJS, Python, Go, Java, C#, Kotlin (JVM), Kotlin (Android) and Swift (iOS) applications.

Repository: https://github.com/gorules/zen
Canonical: https://ross.abutalabs.com/products/gorules-zen
Homepage: https://gorules.io
Language: Rust
License: MIT
License Family: permissive
Last push: 2026-08-25T14:40:37+00:00

## Health v2 (maintenance only)
Score: 97/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 99, longevity 89
- inputs: {"age_days": 1253, "days_push": 8, "days_rel": 9, "gap_med": 0.0, "n_releases_24m": 49}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1945, forks 204 (observed 2026-08-28T04:05:57.670265+00:00)

## What it is
ZEN Engine is an open-source Business Rules Engine written in Rust with native bindings for Node.js, Python, Go, Java, Kotlin, C#, Swift, and Android. Rules are authored as decision tables, graphs, or policy documents in a portable JSON format (JDM) and evaluated in microseconds with identical results across all runtimes.

## Use cases
- evaluate business rules without redeploying code
- run loan approval and credit policy decisions
- implement dynamic pricing rules editable by business teams
- separate decision logic from application code
- share one rules definition across Rust, Node, Python and Java services
- embed a fast rules engine in a microservice hot path
- audit and version business decisions for compliance
- give AI agents a deterministic decision layer

## When to choose
- you need business-readable rules that non-developers can own and edit
- you want one rules definition running identically across multiple languages and platforms
- you need microsecond-level rule evaluation in latency-sensitive paths
- you want portable JSON decision models you can store in files, databases, or services
- you need an MIT-licensed, embeddable alternative to heavyweight commercial BRMS platforms

## When to avoid
- your logic is simple if/else that fits naturally in application code
- you need a full rules management UI with versioning and approvals without using the separate GoRules BRMS product
- you require forward-chaining inference or RETE-style rule engines
- your rules depend on ecosystem features of a specific platform like Drools

## Facets
- artifact type: library
- maturity: stable
- function: workflow-automation, developer-tools, sdk
- domain: developer-tools, backend, fintech, cross-platform
- platform: rust, python, go, jvm, dotnet, cross-platform
- tags: business-rules-engine, decision-engine, decision-tables, expression-language, jdm, rules-as-, bre, decision-automation, automation, nodejs, swift, android, ios

## Member repositories
- gorules/zen (main) score 97

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:57.670265+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 2026-08-30T03:07:22.530350+00:00, confidence not recorded.
  - readme: https://github.com/gorules/zen (fetched 2026-08-28T04:05:57.670265+00:00, sha 172c33fdc4ac)
  - homepage: https://gorules.io (fetched 2026-08-29T10:47:04.695452+00:00, sha 28023cd9d658)
  - site_page: https://docs.gorules.io (fetched 2026-08-29T10:47:04.707543+00:00, sha b7e030fa4085)
  - site_page: https://gorules.io/about (fetched 2026-08-29T10:47:04.709171+00:00, sha 24c4c0a5d533)
  - site_page: https://docs.gorules.io/developers/overview/architecture (fetched 2026-08-29T10:47:04.712942+00:00, sha d6601518a120)
  - site_page: https://docs.gorules.io/changelog (fetched 2026-08-29T10:47:04.715017+00:00, sha 7f66dab931a5)
  - site_page: https://gorules.io/features (fetched 2026-08-29T10:47:04.719494+00:00, sha 0f9e49ecf73a)
  - site_page: https://gorules.io/use-cases/dynamic-pricing (fetched 2026-08-29T10:47:04.704558+00:00, sha 6ee8f38c9c8e)
  - site_page: https://gorules.io/what-is-business-rules-engine (fetched 2026-08-29T10:47:04.710768+00:00, sha 52626c0f7aa8)
  - site_page: https://gorules.io/pricing (fetched 2026-08-29T10:47:04.717604+00:00, sha 1d4d20c00c75)
- Data as of 2026-08-30T08:39:29.467469+00:00.