Mise Fy

mise-fy

Introduction to Humans

Best-practices, tips, and gotchas to maximize the use of mise (along-side hk) distilled from experience building dev (& CI) setups that ✨just works ✨ for diverse teams at different levels that you and your agents would love to use!

The skill has two modes to trigger for:

1. Provide tips & gotchas to agents when working with Mise. (duhh!)
2. Mise-fy 🪄 an existing project and transform it to a recommended structure.

Read each topic's reference in ./references to learn more about what the skill encodes.

[!TIP] The skill is written and optimized to be used by models with coherence level similar to Opus 4.8 or GPT 5.5, especially when mise-fying.

The skill does not enumerate all of Mise's features. It relies on Agents world knowledge, and ability to read docs (and it ask agents to!) but guide the agent to best practices. I may cover more use-cases later!

Is this a Mise skill ? or a good local dev setup skill ?

Kinda both; Mise is THE tool to use to have a great UX in your dev setups, so there is a lot of overlap. However, the skill is primarily focused on Mise itself, and only encode tips/gotchas when Mise is involved. It'll be a good skill to pair with "local-setup" Skill that is runtime specific (maybe soon!).

So What does the skill encode exactly ?

The skill encodes what needs for dev setup to just work, stay discoverable, and guide you to be set up correctly.

It just works. Clone the repo, run mise trust && mise run setup, and you're done. Tools install pinned and locked, so your versions match everyone else's and CI's. Setup is idempotent and cached, so re-running it is cheap (and for worktrees too!), and the git hooks install themselves on mise install, and will nag you if you didn't (so u trust every one and their agent get all local linters/tests/validations)!

It's discoverable. Tasks follow the same names in every repo

How to use the Skill

The skill uses progressive disclosure: each area routes to a references/ file holding the actual rules and best practices. Read the matching one before planning or acting, not after. SKILL.md alone is not enough. Plan ahead, and read all references you'll need!

When to read references

Always read at-least 1 reference from the router below. Depending on your goal you might want to read more than 1 reference. Be eager to load local .md references. Do not load online links/references unless you really need to, default to trust your knowledge. Only load online reference when you need to learn more.

Router

Install mise (machine setup, not project setup) -> references/install.md Install via package manager, activate the shell, shims for non-interactive shells, completions.

Dev tools / runtimes (install, pin, update, backends, lockfile, lazy/uncommon tools) -> references/tools.md Installing a tool or runtime; lazy-installing uncommon tools (task-scoped tools & committed ./bin/ tool stubs) instead of [tools] for everyone.

Runtime integration (per-runtime: package managers, dep install) -> references/runtimes/.

• Node -> runtimes/node.md

Env & vars (project env, dotenv, secrets) -> references/env.md [env], _.file/_.path/_.source, templating, required vars, default fallbacks, redaction, updating PATH, loading .env files, config environments (MISE_ENV), shell aliases.

Tasks (run scripts, build pipelines, watch) -> references/tasks.md TOML vs file tasks, depends/wait_for, sources/outputs caching, running and parallelism, mise watch (re-run on change).

Hooks (directory & lifecycle: enter/cd, watch_files, postinstall) -> references/hooks.md Keeping enter/cd hooks offline-safe (MISE_OFFLINE, or they hang the shell), trust impact, the shim caveat. For git/pre-commit hooks specifically, see hk below.

hk Hooks (pre-commit / git hooks) -> references/hk.md hk.pkl (Pkl, lives at .config/hk.pkl), check vs fix, builtins, mise integration, install, extending with custom steps, the .config/ home for linter configs.

CI (running mise tasks/tools in CI: shims, caching, pinning, tokens) -> references/ci.md General platform-agnostic CI rules; platform specifics under references/ci/:

• GitHub Actions -> ci/github.md

mise-fy an existing project (migrate + audit) -> references/mise-fy.md Step-by-step conversion from custom/asdf/Makefile, plus a full audit checklist. References every other doc.

Project docs (README + AGENTS.md onboarding) -> references/docs.md What to put in README.md and AGENTS.md/CLAUDE.md so a human and an agent can install mise, set up, run tasks, and extend the setup. Part of every mise-fy/audit.

Reference setup (canonical example layout) -> references/reference-setup-and-patterns.md Annotated example file tree + mise.toml to copy from.

Complementary Skills

CI/CD (checks/release/publish workflows, gating, signing, and community hygiene) -> load cicd-fy skill, if installed (from same author). This skill covers running mise in CI; the pipeline's shape is cicd-fy's domain.

Always applies (regardless of task)

These hold no matter which reference you loaded; check them even when fixated on one task. Unlike the opinionated best practices (scope those to your goal; see top), these are the safety/correctness floor: apply them even on a one-tool change, not polish you'd defer.

1. Untrusted config errors out. A mise.toml containing [env], hooks, templates, or task logic hard-errors as a whole file until mise trust (interactive shells prompt to trust; non-interactive ones error). Only a bare min_version + plain-string [tools]/[tasks] file loads untrusted (since 2026.6.6). A fresh clone needs mise trust (or a trusted_config_paths entry).
2. Some features need experimental = true and may change between releases. If a documented flag errors, check whether it's gated.
3. Set min_version (root level, not under [settings]): the oldest release that supports every feature the config uses, never below the known-vulnerable floor (2026.6.5), and never above what the author has installed. An old client is then told to update instead of failing on a feature it lacks.
4. Avoid GitHub rate limits on tool installs (local and CI): set github.gh_cli_tokens and github.use_git_credentials under [settings]. mise tries the gh CLI token first, falls back to git credentials, fails open. In CI a GITHUB_TOKEN env var works too (see ci.md).
5. Mise moves fast. When you hit a wall, check the recent changelog alongside the docs.
6. Shims don't expose every mise activate feature (e.g. some env-on-cd); local-vs-CI mismatches often trace here. See install.md / ci.md.
7. Always be aware of Fast path vs slow path concept. Whatever runs many times a day (e.g. check, the enter hook, pre-commit) is fast-path: cheap, offline-safe, non-interactive. A setup is slow-path: allowed to be slow, online, interactive. Never make a fast-path task depend on a slow-path one, nag instead; the lane map is the one list of members.
8. More Generally, always think of how often a task is going to be run by the user. And never make tasks that belong to different cadences depend on each other.