# substantial/updeep

Easily update nested frozen objects and arrays in a declarative and immutable manner.

Repository: https://github.com/substantial/updeep
Canonical: https://ross.abutalabs.com/products/updeep
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2023-02-21T15:41:55+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4051, "days_push": 1289, "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 1180, forks 38 (observed 2026-08-28T04:03:53.451459+00:00)

## What it is
A small JavaScript utility library for declaratively updating deeply nested frozen objects and arrays immutably. It returns the same reference when nothing changes, making it ideal for reference-equality change detection.

## Use cases
- update nested objects immutably in JavaScript
- declarative deep updates for Redux reducers
- avoid re-renders with reference equality checks
- freeze and update immutable data structures
- curried functional updates with lodash/fp or Ramda

## When to choose
- you need immutable deep updates with minimal API surface
- you rely on reference equality for change detection
- you want frozen, predictable state objects

## When to avoid
- you need a full state-management solution
- you prefer immer-style mutable draft APIs
- you don't want a lodash dependency

## Facets
- artifact type: library
- maturity: maintenance
- function: serialization, developer-tools
- domain: web-development, frontend, developer-tools
- platform: browser
- tags: immutable-data, functional-programming, state-updates, deep-updates, frozen-objects, redux-helper, nodejs, javascript

## Member repositories
- substantial/updeep (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:53.451459+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 2026-08-30T06:25:21.874205+00:00, confidence not recorded.
  - readme: https://github.com/substantial/updeep (fetched 2026-08-28T04:03:53.451459+00:00, sha 891a5c3534d8)
  - registry_npm: https://registry.npmjs.org/updeep (fetched 2026-08-29T12:32:13.357400+00:00, sha b70f5830f906)
- Data as of 2026-08-30T08:39:29.467469+00:00.