inv[oke] core usage

See also

This page documents invoke’s core arguments, options and behavior. For details on invoking user-specified tasks, see Invoking tasks.

Core options and flags

invoke’s usage looks like:

$ inv[oke] [--core-opts] task1 [--task1-opts] ... taskN [--taskN-opts]

All core options & flags are below; almost all of them must be given before any task names, with a few (such as --help) being specially looked for anywhere in the command line.


Print (line-separated) valid tab-completion options for an Invoke command line given as the ‘remainder’ (i.e. after a --). Used for building shell completion scripts.

For example, when the local tasks tree contains tasks named foo and bar, and when foo takes flags --foo-arg and --foo-arg-2, you might use it like this:

# Empty input: just task names
$ inv --complete --

# Input not ending with a dash: task names still
$ inv --complete -- foo --foo-arg

# Input ending with a dash: current context's flag names
$ inv --complete -- foo -

For detailed examples of how to use this option, see the bundled completion scripts stored in completion/ in the source distribution.


Set default value of run()’s ‘hide’ kwarg.


Disable task deduplication.


Prompt at the start of the session (before executing any tasks) for the sudo.password configuration value. This allows users who don’t want to keep sensitive material in the config system or their shell environment to rely on user input, without otherwise interrupting the flow of the program.


By default, Invoke disables bytecode caching as it can cause hard-to-debug problems with task files and (for the kinds of things Invoke is typically used for) offers no noticeable speed benefit. If you really want your .pyc files back, give this option.

-c STRING, --collection=STRING

Specify collection name to load.

-d, --debug

Enable debug output.

-e, --echo

Echo executed commands before running.

-f, --config

Specify a runtime configuration file to load.

-h STRING, --help=STRING

When given without any task names, displays core help; when given with a task name (may come before or after the task name) displays help for that particular task.

-l, --list=STRING

List available tasks. Shows all tasks by default; may give an explicit namespace to ‘root’ the displayed task tree to only that namespace. (This argument may contain periods, as with task names, so it’s possible to show only a small, deep portion of the overall tree if desired.)

-D, --list-depth=INT

Limit --list display to the specified number of levels, e.g. --list-depth 1 to show only top-level tasks and namespaces.

If an argument is given to --list, then this depth is relative; so --list build --list-depth 1 shows everything at the top level of the build subtree.

Default behavior if this is not given is to show all levels of the entire task tree.

-F, --list-format=STRING

Change the format used to display the output of --list; may be one of:

  • flat (the default): single, flat vertical list with dotted task names.

  • nested: a nested (4-space indented) vertical list, where each level implicitly includes its parent (with leading dots as a strong visual clue that these are still subcollection tasks.)

  • json: intended for consumption by scripts or other programs, this format emits JSON representing the task tree, with each ‘node’ in the tree (the outermost document being the root node, and thus a JSON object) consisting of the following keys:

    • name: String name of collection; for the root collection this is typically the module name, so unless you’re supplying alternate collection name to the load process, it’s usually "tasks" (from
    • help: First line of collection’s docstring, if it came from a module; null otherwise (or if module lacked a docstring.)
    • tasks: Immediate children of this collection; an array of objects of the following form:
      • name: Task’s local name within its collection (i.e. not the full dotted path you might see with the flat format; reconstructing that path is left up to the consumer.)
      • help: First line of task’s docstring, or null if it had none.
      • aliases: An array of string aliases for this task.
    • default: String naming which task within this collection, if any, is the default task. Is null if no task is the default.
    • collections: An array of any sub-collections within this collection, members of which which will have the same structure as this outermost document, recursively.

    The JSON emitted is not pretty-printed, but does end with a trailing newline.

-p, --pty

Use a pty when executing shell commands.

-r STRING, --search-root=STRING

Change root directory used for finding task modules.

-V, --version

Show version and exit.

-w, --warn-only

Warn, instead of failing, when shell commands fail.

Shell tab completion

Invoke’s philosophy is to implement generic APIs and then “bake in” a few common use cases built on top of those APIs, and tab completion is no different. Generic tab completion functionality is provided by the --complete core CLI option described above, and we distribute a handful of ready-made wrapper scripts aimed at the most common shells such as bash and zsh (plus others). To use one of these scripts:

  • Obtain the source distribution, or visit the /completion/ folder on Github, and place a copy of the appropriate file (e.g. /completion/bash for Bash users) somewhere on your local system.

  • source the file in your shell login file (e.g. .bash_profile, .zshrc).

  • By default, tabbing after typing inv or invoke will display task names from your current directory/project’s tasks file.

  • Tabbing after typing a dash (-) or double dash (--) will display valid options/flags for the current context: core Invoke options if no task names have been typed yet; options for the most recently typed task otherwise.

    • Tabbing while typing a partial long option will complete matching long options, using your shell’s native substring completion. E.g. if no task names have been typed yet, --e<tab> will offer --echo as a completion option.
  • Hitting tab when the most recent typed/completed token is a flag which takes a value, will ‘fall through’ to your shell’s native filename completion.

    • For example, prior to typing a task name, --config <tab> will complete local file paths to assist in filling in a config file.