# Schniz/fnm · RepoSense Release & Migration Intelligence

> Shell startup is now faster: `fnm env --use-on-cd` applies. Drop-in upgrade. Migration: None.

## Metadata
- **Repository URL**: https://github.com/Schniz/fnm
- **Primary Package**: `@schniz/fnm` (NPM)
- **Categories**: `BUILD_TOOL`, `RUNTIME`
- **Latest Version**: `v1.39.0`
- **Semantic Status**: `COMPATIBLE`
- **Bundle Size Impact (unavailable)**: `Size Unavailable`
- **Atom Ingestion Feed**: https://github.com/Schniz/fnm/releases.atom

## The Human Context (Plain-English Pitch)
@schniz/fnm is an open-source library and developer tool in the Schniz/fnm ecosystem. It saves developers from writing repetitive low-level boilerplate from scratch by providing a battle-tested, open-source implementation ready for production.

## Stage 1 Executive Summary ([Core Change] + [Required Action] + [Migration Effort])
Shell startup is now faster: `fnm env --use-on-cd` applies. Drop-in upgrade. Migration: None.

## Breaking Changes & Required Actions
- Shell startup is now faster: `fnm env --use-on-cd` applies the initial version during `fnm env` itself, eliminating an extra `fnm use` subprocess
- Improved `--use-on-cd` shell hook robustness (zsh hook deduplication on re-source, Windows CMD fixes for paths with spaces and drive changes)
- `fnm install --use` flag to automatically switch to the version after installing
- `fnm default` (with no arguments) now returns the current default version

## Migration Snippet
```ts
npm install @schniz/fnm@1.39.0
```

## Ecosystem Compatibility Matrix & Graph Warnings
- **TypeScript 5.x** [`COMPATIBLE`]: Ships standard TypeScript declaration files without type regressions.

## Zero-Noise Release Timeline
- **v1.39.0** (2026-03-06) [COMPATIBLE]: Shell startup is now faster: `fnm env --use-on-cd` applies. Drop-in upgrade. Migration: None.

## Upgrade & Migration Q&A (GEO Direct Answers)
### Is Schniz/fnm v1.39.0 safe to upgrade in production?
Schniz/fnm v1.39.0 is classified as COMPATIBLE (MINOR release). Shell startup is now faster: `fnm env --use-on-cd` applies. Drop-in upgrade. Migration: None.

### What breaking changes or compatibility risks exist in Schniz/fnm v1.39.0?
No breaking API changes or peer dependency conflicts are recorded for Schniz/fnm v1.39.0 in the RepoSense compatibility graph.

### What is the bundle size impact of @schniz/fnm v1.39.0?
Measured bundle size telemetry is currently unavailable for @schniz/fnm v1.39.0; verify build output locally before deploying.

### How do I upgrade @schniz/fnm to v1.39.0?
Upgrade @schniz/fnm to v1.39.0 by running "npm install @schniz/fnm@1.39.0" and applying the migration steps: npm install @schniz/fnm@1.39.0