Actions & Runtimes

Actions are the core units of work in Mudyla. They are defined in Markdown files under .mdl/defs/.

Action Definition

An action is defined by a header starting with # action: <name>. The name must be kebab-case.

# action: build-app

Runtimes

Mudyla supports Bash and Python actions.

Bash Actions

Bash actions use standard shell script syntax.

# action: bash-example

```bash
set -euo pipefail
echo "Running in Bash"
ret status:string="success"
```

Features:

• Expansions: Use ${sys.root}, ${env.VAR}, ${args.arg} syntax.
• Return Values: Use the injected ret function to return typed data.
• Dependencies: Use dep action.name or ${action.name.output}.

Python Actions

Python actions allow for complex logic using the mdl object.

# action: python-example

```python
import os
print("Running in Python")
mdl.ret("status", "success", "string")
```

Features:

• mdl API: Access args, flags, env, and dependencies via the mdl object.
• Standard Library: Full access to Python standard library.
• Pypi Packages: Can use packages available in the environment.

Return Types

Actions must return typed values. These are validated at runtime.

• int: Integer.
• string: Text string.
• bool: Boolean (0 or 1).
• file: Path to a file (must exist).
• directory: Path to a directory (must exist).

Properties

You can define document-wide properties at the top of the Markdown file.

# properties

- `sequential` # Forces sequential execution for actions in this file