# d5/tengo

A fast script language for Go

Repository: https://github.com/d5/tengo
Canonical: https://ross.abutalabs.com/products/tengo
Homepage: https://tengolang.com
Language: Go
License: MIT
License Family: permissive
Topics: golang, go, script, embedded-language, compiler, vm, programming-language, tengo
Last push: 2026-04-29T08:48:00+00:00

## Health v2 (maintenance only)
Score: 58/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 79, release rhythm 8, longevity 100
- inputs: {"age_days": 2793, "days_push": 126, "days_rel": 466, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3831, forks 336 (observed 2026-08-28T04:08:23.429474+00:00)

## What it is
Tengo is a small, dynamic, fast scripting language implemented in pure Go, compiled to bytecode and executed on a stack-based VM. It is designed to be securely embedded in Go applications as an extensible scripting/rules layer, and also ships as a standalone CLI with a REPL.

## Use cases
- embed a scripting language in a go application
- build a rules engine with user-editable logic
- run sandboxed user scripts securely
- write a data pipeline in a small dynamic language
- evaluate dynamic expressions at runtime in go
- use a lightweight scripting language with a REPL

## When to choose
- you need a fast, dependency-free embeddable script language for Go
- security and sandboxing of user-supplied scripts matter
- you want better VM performance than Lua/JS interpreters on Go

## When to avoid
- you need a rich standard library or large ecosystem
- you need native-code performance
- you prefer a mature mainstream scripting language like Lua or JavaScript

## Facets
- artifact type: library
- maturity: stable
- function: interpreter, compiler, programming-language, cli
- domain: programming-languages, developer-tools
- platform: go, cross-platform, cli
- tags: embedded-scripting, bytecode-vm, scripting-language, rules-engine, go-embedding, automation

## Member repositories
- d5/tengo (main) score 58

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:23.429474+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 2026-08-29T18:26:19.278184+00:00, confidence not recorded.
  - readme: https://github.com/d5/tengo (fetched 2026-08-28T04:08:23.429474+00:00, sha c4c47c70b382)
  - homepage: https://tengolang.com (fetched 2026-08-29T09:20:59.086885+00:00, sha 4c4e2c34500b)
- Data as of 2026-08-30T08:39:29.467469+00:00.