# hashicorp/go-immutable-radix

An immutable radix tree implementation in Golang

Repository: https://github.com/hashicorp/go-immutable-radix
Canonical: https://ross.abutalabs.com/products/go-immutable-radix
Language: Go
License: MPL-2.0
License Family: copyleft
Last push: 2026-07-27T07:45:34+00:00

## Health v2 (maintenance only)
Score: 65/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 94, release rhythm 8, longevity 100
- inputs: {"age_days": 4111, "days_push": 37, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1107, forks 81 (observed 2026-08-28T04:03:36.656769+00:00)

## What it is
A Go library implementing an immutable radix tree optimized for sparse nodes, with O(k) operations, ordered iteration, and transactional batch updates. Version 2 adds generics for compile-time type safety.

## Use cases
- implement a prefix lookup structure in Go
- find the longest prefix match for keys like IP routing
- iterate keys in sorted lexicographic order
- perform range scans over string keys
- build persistent snapshots of a key-value map
- batch insert and delete operations efficiently

## When to choose
- you need immutable, snapshot-friendly ordered key-value storage in Go
- you need fast longest-prefix matching or range scans
- you want better cache locality than a hash table for string keys

## When to avoid
- you need a mutable tree that updates in place (use go-radix instead)
- you need approximate or fuzzy matching rather than exact prefix semantics
- you are not working in Go

## Facets
- artifact type: library
- maturity: stable
- function: search-engine, developer-tools
- domain: developer-tools, databases
- platform: go
- tags: radix-tree, immutable-data-structures, data-structures, prefix-tree, generics, algorithms

## Member repositories
- hashicorp/go-immutable-radix (main) score 65

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:36.656769+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 2026-08-30T06:44:02.265719+00:00, confidence not recorded.
  - readme: https://github.com/hashicorp/go-immutable-radix (fetched 2026-08-28T04:03:36.656769+00:00, sha 9e727af83155)
- Data as of 2026-08-30T08:39:29.467469+00:00.