jan-cli
jan is a Rust CLI that turns a YAML command tree into a discoverable, scriptable interface. Each node can expose nested subcommands (with progressive --help at every level) or delegate to a real program via exec. Invocations can be recorded in SQLite, keyed by git branch, so agents and humans can audit what ran in each checkout.
The binary does not ship a built-in command tree. Point it at a directory once with jan use <DIR>, then jan --help lists the live subcommands from that tree.
[!WARNING] A jan tree is executable code, not configuration data.
jan usemakes that tree the persistent source of commands for later invocations, and its YAML can launch arbitrary programs with your user account's permissions. Only use trees you have reviewed and trust. Bundle manifest hashes detect corruption; they do not authenticate the bundle's publisher.
Table of contents
- Installation
- Security model
- Quick start
- Spec resolution
- Command-line reference
- Environment variables
- Help and discovery
- YAML spec format
- Script entries: path, dependencies, requires, env
- Audit log
- Built-in commands
- Portable scripts workflow
- Examples in this repo
- Troubleshooting
- License
Installation
From crates.io
You still need a spec tree on disk (see Quick start).
From source (monorepo)
# Prefer a reviewed personal tree (canonical: dotfiles/jan)
Install a trusted spec bundle
# Export a reviewed personal tree (canonical: dotfiles/jan)
# Import on any machine
# → verifies archive structure and manifest hashes, then unpacks
# to ~/.config/jan/scripts/; this does not authenticate the publisher
# Review the extracted YAML before making it active.
Or point jan at any existing tree once:
Security model
- A preferred tree can execute arbitrary commands and set child environment
variables.
jandoes not sandbox commands or reduce their privileges. jan usepersists an absolute tree path. Futurejancommands use the current contents at that path without a signature, content lock, or per-run prompt.include:paths are confined to the preferred tree, but included YAML has the same execution authority as the root file.jan bundlemanifests provide integrity checks only. They do not prove who created a bundle or whether its contents are trustworthy.- The SQLite audit database is mutable local telemetry and may contain sensitive command-line arguments. It is not a tamper-proof security log.
See SECURITY.md for the detailed threat model and open findings.
Quick start
1. Review and trust a tree, prefer it once, then use jan with no path flags:
# or: jan use ~/.config/jan/scripts
2. Demo / examples trees in this repo:
Spec resolution
jan loads the YAML tree from the preferred directory saved by jan use (stored in ~/.config/jan-cli/config.json, overridable with JAN_CONFIG_DIR).
The directory is expected to be a properly formatted jan tree (entry YAML plus any include: fragments). After jan use, run jan --help to list live subcommands.
A common install layout (after jan-install.sh):
~/.config/jan/scripts/
scripts.spec.yaml
scripts.yaml # category index (flat layout)
git.yaml …
env.sh # notes that you should `jan use` this directory
Command-line reference
jan [GLOBAL OPTIONS] <subcommand> ... [passthrough args]
| Flag | Env | Default | Description |
|---|---|---|---|
-h, --help |
— | — | List live subcommands from the preferred tree (+ built-ins) |
-V, --version |
— | — | Print version |
-v, --verbose |
— | off | Print preferred directory resolution (stderr) |
--cwd DIR |
— | . |
Working directory for subprocesses and git branch detection |
--db FILE |
JAN_DB |
see Audit log | SQLite audit database path |
--no-log |
— | off | Disable audit logging |
--branch NAME |
JAN_BRANCH |
git rev-parse |
Git branch label stored in audit log |
Notes:
- Trailing arguments after the matched command path are forwarded only when the leaf defines
exec.passthrough: true. - Use
--before passthrough args if they start with-:jan scripts foo run -- --help.
Environment variables
| Variable | Purpose |
|---|---|
JAN_CONFIG_DIR |
Override XDG config dir for jan use preference (default ~/.config/jan-cli) |
JAN_DB |
Default audit database path |
JAN_BRANCH |
Default --branch |
JAN_OS |
Override platform filter id for os: in YAML (linux, macos, windows, …) |
JAN_INSTALL_DIR |
Default unpack directory for jan-install.sh only |
JAN_SCRIPTS_ROOT |
Base for resolving relative script path entries |
Help and discovery
jan uses progressive help: place --help or -h immediately after the subcommand prefix you want to inspect.
Rules:
--helpmust come right after the prefix being queried.jan git r --helpis valid;jan git r rev-parse --helpis not (jan treats trailing--helpon exec leaves as an error).- Leaf nodes with
execand no children print a short note that they run an external program. - Subcommands forwarded to external tools (with
passthrough: true) receive their own--helpwhen you pass it after--or as trailing args.
ptional metadata and a commands map. Each command node can define:
| Field | Type | Description |
|---|---|---|
about |
string | Shown in help text |
commands |
map | Nested subcommands |
exec |
object | Run a program (argv, optional passthrough) |
include |
string | Load subtree from another YAML file (relative path) |
os |
list | Offer this node only on listed platforms (linux, macos, windows; darwin → macos) |
path |
string | Directory prepended to PATH when this script runs |
dependencies |
list | Other script names whose path dirs are prepended first |
requires |
list | External binaries that must exist on PATH before run |
env |
map | Environment variables for the child process |
cron |
string or list | Five-field crontab expression(s); jan cron runs the script's run leaf when local time matches |
Constraints:
- A node cannot define both
execand nestedcommands. - A node with
includecannot also defineexecorcommandsin the same map. exec.argvmust be non-empty; the first element is the program.
Minimal example
metadata:
name: myapp
description: |
Short description shown at the root help level.
commands:
hello:
about: Say hello
exec:
argv:
run-tool:
about: Forward args to an external command
exec:
argv:
passthrough: true
Nested subcommands
commands:
android:
about: Android workflows
commands:
skills:
about: Skill tools
commands:
list:
about: List skills
exec:
argv:
Invoke: jan android skills list
include (split large specs)
Root-level include (list) merges top-level command maps from other files:
include:
- fragments/extra.yaml
commands:
local:
about: Defined in this file
Per-command include (string) grafts a file as that command's subtree:
commands:
git:
include: default/git.yaml
See examples/default.spec.yaml and a personal tree such as dotfiles/jan for real layouts.
exec and passthrough
commands:
diff:
about: Git diff with forwarded paths and flags
exec:
argv:
passthrough: true
Without passthrough: true, trailing CLI arguments are rejected.
Platform filtering (os)
commands:
ports:
os:
about: List listening ports (Linux only)
exec:
argv:
Nodes hidden on other platforms are omitted from help and cannot be invoked.
Time triggers (jan cron)
Put a five-field crontab expression (or a list of them) on a script node or its run child. Then run jan cron from the host crontab (typically every minute) to execute every matching script's run leaf.
commands:
scripts:
commands:
misc:
commands:
morning-note:
about: Append a daily note
cron: "30 10 * * *"
# or: cron: ["30 10 * * *", "0 18 * * *"]
# or: cron: "@hourly"
commands:
run:
exec:
argv:
Nicknames: @yearly / @annually, @monthly, @weekly, @daily / @midnight, @hourly.
Script entries: path, dependencies, requires, env
Script-style commands (e.g. the auto-generated scripts tree) use extra fields so inlined runners can call sibling scripts and external tools.
trackusage:
about: Track command usage
dependencies:
- trackusage-impl
commands:
help:
about: Show description
exec:
argv:
run:
about: Run the script; forwards args
exec:
argv:
passthrough: true
issue:
requires:
env:
ISSUE_EDITOR: vim
commands:
run:
exec:
argv:
passthrough: true
At run time, jan:
- Merges
dependencies,requires,env, andpathfrom every node along the matched chain (deeper nodes overrideenvkeys). - Resolves transitive
dependenciesto other scripts'pathdirectories (cycle-checked). - Prepends those directories, then the script's own
path, toPATH. - Fails early if any
requiresbinary is missing. - Resolves
exec.argv[0]on thePATHjan itself inherited, before the prepends above apply, so a specpathdirectory cannot substitute its ownbashorpython3for the system one. Directories frompath/dependenciesare used only for programs the host does not provide, and anargv[0]containing a/is used verbatim.
Relative path values are resolved against, in order: --cwd, the spec directory, its parent, then JAN_SCRIPTS_ROOT.
Personal utilities live as inlined YAML under a preferred directory such as dotfiles/jan. Edit that tree directly; the old generate_scripts_jan_spec.py helper is retired.
Audit log
By default, every leaf execution is logged to SQLite:
| Column | Content |
|---|---|
ts |
Unix timestamp |
git_branch |
From --branch, JAN_BRANCH, or git rev-parse in --cwd |
cwd |
Working directory |
command_path |
Matched subcommand chain (e.g. git s) |
argv_json |
Full argv passed to the child process |
exit_code |
Child exit code |
spec_root_id |
Link to which spec tree was used |
Default database path:
| OS | Path |
|---|---|
| Linux | ~/.local/share/jan-cli/audit.db |
| macOS | ~/Library/Application Support/jan-cli/audit.db |
| Windows | %LOCALAPPDATA%\jan-cli\audit.db |
Override with --db / JAN_DB, or disable with --no-log.
Useful for agent workflows: each git branch gets a separate audit trail of which jan commands ran.
Built-in commands
These are reserved first-token subcommands (not defined in your YAML):
jan use
Remember a preferred jan directory under XDG config (~/.config/jan-cli/config.json). Works even when no YAML tree is configured yet.
Afterward, plain jan … and jan --help load that tree.
jan bundle
Pack the reachable YAML tree into a ZIP:
| Flag | Description |
|---|---|
-o, --output |
Output zip path (default: jan-spec-bundle.zip) |
--dry-run |
List files instead of writing a zip |
Archive contents:
- All YAML files reachable via
include:under the preferred directory env.sh— reminds you tojan usethe unpack directorymanifest.json— file list and SHA-256 hashes
jan alias
Emit shell aliases for executable leaves (assumes jan use is already configured):
Alias generation rejects names outside [A-Za-z_][A-Za-z0-9_-]* and
shell-quotes every generated command argument.
| Flag | Description |
|---|---|
--jan-bin |
Program name on the RHS (default: jan) |
--shell |
Header dialect: sh, bash, or zsh |
-o |
Write to a file instead of stdout |
Example line:
Portable scripts workflow
See docs/PORTABLE_SCRIPTS.md for the full export/import flow.
# On the target machine:
Examples in this repo
Troubleshooting
no preferred jan directory configured
missing required utilities on PATH: fzf
Install the named tool or remove it from the node's requires: list.
unknown script dependency 'foo'
The dependencies: entry must match another command name in the same tree that has a path:.
unexpected trailing arguments
The leaf does not set exec.passthrough: true. Add it, or drop the extra args.
place --help immediately after the subcommand prefix
Put --help right after the prefix you want help for, not after passthrough argv.
Spec include errors
include: paths are resolved from the root directory selected by jan use.
Absolute paths, .. components, and symlinks that escape that root are rejected
both during normal loading and by jan bundle.
License
MIT — see LICENSE.md.