Task Templates

Task templates let you define reusable task definitions that multiple tasks can extend. They are particularly useful in monorepos or projects with similar task patterns across components.

The Python examples below assume a uv project whose development dependencies include pytest and, for coverage, pytest-cov. Declaring Python as a tool does not install those project packages.

Defining Templates

Templates are defined in the [task_templates.*] section of your mise.toml:

toml

[task_templates."python:build"]
description = "Build a Python project"
run = "uv build"
tools = { python = "3.12", uv = "latest" }
env = { PYTHONPATH = "src" }

[task_templates."python:test"]
description = "Run Python tests"
run = "uv run pytest"
tools = { python = "3.12", uv = "latest" }
depends = ["build"]

Extending Templates

Tasks can extend templates using the extends field:

toml

[tasks.build]
extends = "python:build"

[tasks.test]
extends = "python:test"
run = "uv run pytest --cov"  # Override run while keeping tools, depends

Template Naming

Templates use colon (:) separators for namespacing, similar to task naming conventions in monorepos:

python:build
python:test
rust:cargo:build
node:npm:test

Merge Semantics

When a task extends a template, fields are merged according to these rules:

Field	Behavior
`run`, `run_windows`	Local overrides completely
`tools`	Deep merge (local tools add to or override the template's values)
`env`	Deep merge (local env adds to or overrides the template's values)
`depends`, `depends_post`, `wait_for`	Local overrides completely (not merged)
`dir`	Local overrides; defaults to config_root if not in template
`sources`, `outputs`, `cache`	Local overrides completely
`output`	Local overrides template (if set)
Sandbox deny fields	Compose with task-local settings
Sandbox allow fields	Template and task-local values are combined
`description`, `shell`, `timeout`, etc.	Local overrides template (if set)
`quiet`, `hide`, `raw`, `interactive`, `raw_args`	Not supported on templates (set explicitly on each task)

For run, run_windows, depends, depends_post, wait_for, and sources, an empty local list currently inherits the template's value. In particular, depends = [] does not clear template dependencies. Use a separate template when a task must omit those prerequisites. outputs = [] is an explicit no-files output declaration; cache = { enabled = false } explicitly disables inherited caching.

Example: Deep Merge for Tools

toml

[task_templates."fullstack:build"]
tools = { python = "3.12", node = "18" }

[tasks.build]
extends = "fullstack:build"
tools = { node = "20" }  # Override node, keep python from template
# Result: tools = { python = "3.12", node = "20" }

Example: Deep Merge for Env

toml

[task_templates."python:build"]
env = { PYTHONPATH = "src", DEBUG = "0" }

[tasks.build]
extends = "python:build"
env = { DEBUG = "1" }  # Override DEBUG, keep PYTHONPATH from template
# Result: env = { PYTHONPATH = "src", DEBUG = "1" }

Example: Complete Override for Depends

toml

[task_templates."python:test"]
depends = ["lint", "typecheck"]

[tasks.test]
extends = "python:test"
depends = ["build"]  # Completely replaces template depends
# Result: depends = ["build"] (lint and typecheck NOT included)

Tera Templating

Templates support Tera templating, rendered in the context of the project that uses them:

toml

[task_templates."python:build"]
description = "Build Python project"
dir = "{{ config_root }}"  # Resolves to the PROJECT's directory
run = "uv build"
env = { PROJECT = "{{ config_root | basename }}" }

Available variables (same as regular tasks):

<code v-pre>{{ config_root }}</code> - The project using the template (NOT where the template is defined)
<code v-pre>{{ env.VAR }}</code> - Environment variables
<code v-pre>{{ cwd }}</code> - Current working directory
<code v-pre>{{ vars.* }}</code> - User-defined variables from config

Monorepo Usage

Task templates are especially useful in monorepos where multiple packages share similar build patterns:

toml

# Root mise.toml
monorepo_root = true

[monorepo]
config_roots = ["packages/api", "packages/worker"]

[task_templates."python:build"]
run = "uv build"
tools = { python = "3.12", uv = "latest" }

[task_templates."python:test"]
run = "uv run pytest"
tools = { python = "3.12", uv = "latest" }
depends = ["build"]

[task_templates."python:lint"]
run = "ruff check ."
tools = { python = "3.12", ruff = "latest" }

toml

# packages/api/mise.toml
[tasks.build]
extends = "python:build"

[tasks.test]
extends = "python:test"
run = "uv run pytest --cov"  # Add coverage

[tasks.lint]
extends = "python:lint"

toml

# packages/worker/mise.toml
[tasks.build]
extends = "python:build"

[tasks.test]
extends = "python:test"

[tasks.lint]
extends = "python:lint"

Template scope

Templates come from the active configuration hierarchy, including global and parent configurations. A task selects one by name with extends; declaring a template does not create a runnable task. Use mise tasks info <task> to inspect the resulting task after inheritance.

Prefer repository-owned templates for behavior teammates and CI need to share. Global templates are useful for personal tasks, but another machine will need the same template definition to resolve extends.