jev-tree
npm library that walks a taxonomy with one Jev Choice per level so you can select among thousands of leaves despite the 255-option cap.
Overview
jev-tree solves a practical limit: a Jev Choice question can list at most 255 options, but real catalogs of SKUs, incident types or workflow IDs are bigger, and truncating drops the tail. The library takes a JSON tree of nodes with ids, labels, optional descriptions and children, and calls Jev once per level (or per partition), automatically bucketing oversized sibling lists, so each call is a short, precise question. The default is 32 options per call, configurable up to 255.
You call select() with a state, a question and the shape, and get the chosen leaf's value. Ids need not be valid Jev choice keys because the library sends o0, o1 and so on and maps back. It uses typesafe-ai/jev through the Vercel AI Gateway with ai 7.0.105 on Node 22+, requires an AI Gateway key for live calls, and shares a stack with the author's jevlogs. It ships a guide, API docs, a short explainer film and a public Hugging Face dataset from a bake-off.
What the decision model decides
| Type | Question | Answers |
|---|---|---|
| Choice | Which child branch (and eventually leaf) of the taxonomy fits this state, e.g. which incident type is this? | — |
How it works
- Provide a taxonomy tree and a question
- Ask a Choice over the current level's children (auto-bucketed if large)
- Descend into the chosen branch
- Return the selected leaf's value
Strengths
- Handles catalogs far larger than 255 options
- Avoids truncation dropping the tail
- Short per-call option lists
- Published on npm with CI
Caveats
- Multiple sequential calls add latency
- Errors at a high level propagate down the tree
- Requires Vercel AI Gateway key
Getting started
npm install jev-tree (set AI_GATEWAY_API_KEY).At a glance
- Type
- Project
- Status
- beta
- Language
- TypeScript
- Runtime
- Node
- Has code
- yes
- Has tests
- yes
- License
- MIT
Use cases and integrations
How curated lists describe it
Recursive Choice over a taxonomy so catalogs larger than Jev's 255-option cap still fit
AnotiaWang/awesome-decision-modelsA hierarchical selector that asks Jev to traverse branches when a catalog has too many options for one question.
logicrw/awesome-jev-projectsRecursive choice over taxonomies larger than Jev's direct option limit.
cobanov/awesome-jevRecursive Jev choice over a taxonomy. Select from more than 255 options without breaking TypeSafe Jev's choice cap.
hellogumbo/awesome-jevRecursive Choice over a taxonomy, for picking among more options than a single Choice question allows.
MrJev/awesome-jev
Frequently asked questions
Why not one big Choice?
Jev caps a Choice at 255 options, and truncating the list drops valid answers.
How many options per call?
32 by default, configurable up to 255 via maxFanout.
Which API key does it need?
A Vercel AI Gateway key, not an OpenAI key.
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