Chezmoi

Chezmoi

Corrections for working with chezmoi. Claude knows chezmoi exists but consistently guesses wrong on naming attributes, when to template vs script, and how packages are installed. This is the knowledge delta — verify anything not here against the official docs (each section links the canonical page).

The One Rule: Never Edit the Target

Source state (the repo, chezmoi source-path) is the authority. The destination (~) is generated. Editing ~/.zshrc directly is wrong — chezmoi apply regenerates it from source and your edit is gone.

• Start managing a file: chezmoi add ~/.zshrc (captures it into source with the right attributes — don't hand-create dot_zshrc).
• Change a managed file: chezmoi edit ~/.zshrc (opens the source; add --apply to apply on save).
• Pull a manual edit back into source: chezmoi re-add ~/.zshrc (preserves templates/encryption; add --force overwrites unconditionally).
• Preview / deploy: chezmoi diff then chezmoi apply.
• Commit: chezmoi git -- commit -am "…" or work in chezmoi cd. Committing doesn't apply, and applying doesn't commit — they're separate.
• chezmoi update = git pull in the source dir then apply. chezmoi apply alone never pulls.

Concepts: https://www.chezmoi.io/reference/concepts/ · Daily ops: https://www.chezmoi.io/user-guide/daily-operations/

Source Naming: Attributes Are Prefixes, in a Fixed Order

Attributes are filename prefixes ending in _. Order is mandatory. For regular files:

encrypted_  private_  readonly_  empty_  executable_  dot_

dot_ is always last (closest to the name). So private_dot_ssh, executable_dot_bashrc, encrypted_private_dot_netrc — never dot_private_…. Directories use a different set/order: remove_ external_ exact_ private_ readonly_ dot_. The .tmpl suffix goes at the very end; .literal stops attribute parsing (use it when a real filename contains _ that looks like an attribute).

Authoritative table (don't guess the order — check it): https://www.chezmoi.io/reference/source-state-attributes/ · Target types: https://www.chezmoi.io/reference/target-types/

Templates: When and How

A file is a template if it ends in .tmpl (or lives in .chezmoitemplates/). Go text/template + chezmoi/sprig functions.

• Use a template when the whole file varies by machine/OS/secret. Don't template a file you only partially own (app-managed config) — use a modify_ script instead.
• modify_ files are scripts that receive the current file on stdin and emit the new contents on stdout (a .tmpl suffix renders the script before it runs, like any other script). Simpler alternative: put a chezmoi:modify-template marker line in the file — chezmoi strips those lines and treats the rest as a template with the current contents in .chezmoi.stdin, whose output becomes the new file (no separate script needed).
• Data precedence (later wins): built-in .chezmoi.* < .chezmoidata.<fmt> files < [data] in the config. .chezmoidata files are not themselves templates (read before the engine runs). See everything with chezmoi data.
• Test without applying: chezmoi execute-template '{{ .chezmoi.os }}' or pipe a file in. Add --init to test config/init-only functions like promptStringOnce.
• Secrets come from password-manager functions (onepasswordRead, bitwardenFields, …) evaluated at apply time — see Secrets below.
• .chezmoitemplates/ gotcha: {{ template "name" }} passes no data; the partial can't see .chezmoi.*. Pass context explicitly: {{ template "name" . }}.
• Strict mode is on (missingkey=error) — a typo'd variable errors rather than rendering empty. Emit literal braces with {{ "{{" }}.

Templating guide: https://www.chezmoi.io/user-guide/templating/ · Functions: https://www.chezmoi.io/reference/templates/functions/ · Partial-file management: https://www.chezmoi.io/user-guide/manage-different-types-of-file/

Scripts: For Actions, Not File Contents

Scripts are source files prefixed run_. They run on every chezmoi apply unless you scope them. Use them to do things (install packages, system setup) — never to generate config files (that's what target files/templates are for).

• run_once_ — runs once per unique content hash; editing the script re-runs it.
• run_onchange_ — re-runs whenever the content changes.
• Both hash after template rendering, so a .tmpl script re-runs when its rendered output changes.
• Order: scripts interleave with files in ASCII order; before_/after_ break out of it. Combine as run_once_before_, run_onchange_after_, etc.
• Put scripts with no corresponding target in .chezmoiscripts/.
• Write them idempotent regardless — they may run during diffs or after state resets.

Scripts guide: https://www.chezmoi.io/user-guide/use-scripts-to-perform-actions/

Packages vs Externals: Two Different Mechanisms

These get conflated. chezmoi has no built-in package manager.

• Install system packages (brew/apt/dnf): a templated run_onchange_ script that ranges over a package list in .chezmoidata/packages.yaml. Because the list is inlined into the rendered script, adding a package changes the script body and run_onchange_ re-fires — no manual hash needed.

  # .chezmoidata/packages.yaml
  packages: { darwin: { brews: [git, ripgrep, fzf] } }
  

  # run_onchange_install-packages.sh.tmpl
  {{ if eq .chezmoi.os "darwin" -}}
  #!/bin/bash
  brew install {{ .packages.darwin.brews | join " " }}
  {{ end -}}
  

  The manual # {{ include "file" | sha256sum }} comment trick is only for when a script reads an external file at runtime rather than inlining it.

• Vendor external files/archives/repos (oh-my-zsh, vim plugins, a binary): declare them in .chezmoiexternal.toml. Types: file, archive, archive-file, git-repo. Set refreshPeriod (default never re-downloads); chezmoi apply -R forces a refresh. URLs can be templated for per-OS/arch downloads.

Install packages: https://www.chezmoi.io/user-guide/advanced/install-packages-declaratively/ · Externals: https://www.chezmoi.io/reference/special-files/chezmoiexternal-format/

Secrets

Never commit plaintext. Two complementary approaches:

• Password-manager functions (idiomatic, zero secrets in repo): templates call onepasswordRead, bitwardenFields, etc., fetching at apply time. The repo holds only the reference.
• Encryption at rest: encrypted_ prefix (age or gpg) stores ciphertext in the repo; chezmoi edit transparently decrypts/re-encrypts. Don't hand-decrypt source files.

Be careful enabling autoCommit/autoPush — a stray plaintext secret becomes permanent public history.

Password managers: https://www.chezmoi.io/user-guide/password-managers/ · Encryption: https://www.chezmoi.io/user-guide/encryption/

Machine Differences

One repo, one branch — chezmoi enforces a single source of truth by design (no multi-repo/branch dotfiles). Vary by machine with templates, not branches:

• Built-ins: .chezmoi.os, .chezmoi.arch, .chezmoi.hostname, .chezmoi.config.
• .chezmoiignore is itself a template — use conditionals to include/exclude files per machine.
• Per-machine values belong in .chezmoidata/ or are prompted once at init (promptStringOnce) into the generated config.
• Scope is the home directory; chezmoi is not for /etc (use Ansible/etc. for that).

Machine differences: https://www.chezmoi.io/user-guide/manage-machine-to-machine-differences/

Debugging

• chezmoi doctor — health/config check first.
• chezmoi diff / chezmoi apply --dry-run --verbose — see what would change.
• chezmoi cat ~/.zshrc — show the rendered target.
• chezmoi execute-template … — test template logic in isolation.
• chezmoi managed / unmanaged / status / verify — audit what's tracked and whether it matches.
• Force a script to re-run: chezmoi state delete-bucket --bucket=scriptState.

FAQ: https://www.chezmoi.io/user-guide/frequently-asked-questions/ · execute-template: https://www.chezmoi.io/reference/commands/execute-template/

Bootstrapping a new machine (chezmoi init --apply): https://www.chezmoi.io/user-guide/setup/