Zen Generator 🚀

A bidirectional Python code generator that converts between AsyncAPI 3.0 specifications and Python code (pure Python or FastAPI implementations).

Features ✨

• 🔄 Bidirectional conversion between AsyncAPI 3.0 and Python code
• 🐍 Generate Python code from AsyncAPI 3.0 specifications:
  • 🐍 Pure Python implementations with type hints
  • ⚡ FastAPI endpoints with Pydantic models
• 📄 Generate AsyncAPI 3.0 specifications from Python code
• 🧠 Automatic type inference and mapping
• ⚡ Support for both async and sync functions

Installation 📦

with uv:

uv tool install zen-generator

with pipx:

pipx install zen-generator

with uvx:

uvx zen-generator

Important

Currently, only model and function definitions in the components block of the AsyncAPI file are supported. Inline definitions are not supported.

Note

This code snippet includes a custom definition for declaring required parameters in model/function definitions. Specifically, the required keyword is used to specify mandatory fields, as shown below:

required:
  - user_id

This ensures that the user_id parameter is always provided when the model or function is utilized.

Quick Start 🏃

Convert between AsyncAPI 3.0 specifications and Python code:

# Generate FastAPI implementation from AsyncAPI spec
uvx zen-generator fastapi

# Generate pure Python implementation from AsyncAPI spec
uvx zen-generator pure-python

# Generate AsyncAPI spec from Python code
uvx zen-generator asyncapi-documentation

Command Line Interface

The CLI is built with Typer and provides three main commands:

Usage:

$ [OPTIONS] COMMAND [ARGS]...

Options:

• --install-completion: Install completion for the current shell.
• --show-completion: Show completion for the current shell, to copy it or customize the installation.
• --help: Show this message and exit.

Commands:

• asyncapi-documentation
• pure-python
• fastapi

asyncapi-documentation

Usage:

$ asyncapi-documentation [OPTIONS]

Options:

• --models-file PATH: [default: models.py]
• --functions-file PATH: [default: functions.py]
• --output-file PATH: [default: asyncapi.yaml]
• --application-name TEXT: [default: Zen]
• --help: Show this message and exit.

pure-python

Usage:

$ pure-python [OPTIONS]

Options:

• --asyncapi-file PATH: [default: asyncapi.yaml]
• --models-file PATH: [default: models.py]
• --functions-file PATH: [default: functions.py]
• --application-name TEXT: [default: Zen]
• --is-async / --no-is-async: [default: no-is-async]
• --help: Show this message and exit.

fastapi

Usage:

$ fastapi [OPTIONS]

Options:

• --asyncapi-file PATH: [default: asyncapi.yaml]
• --models-file PATH: [default: models.py]
• --functions-file PATH: [default: functions.py]
• --application-name TEXT: [default: Zen]
• --is-async / --no-is-async: [default: no-is-async]
• --help: Show this message and exit.

Generated Code Examples 📝

Pure Python Implementation (models.py)

from __future__ import annotations

from typing import TypedDict


class UserModel(TypedDict):
    id: int
    name: str
    email: str | None = None

Pure Python Implementation (functions.py)

from __future__ import annotations

from .models import UserModel

def get_user(user_id: int) -> UserModel:
    ...

FastAPI Implementation (models.py)

from __future__annotations

from pydantic import BaseModel

class UserModel(BaseModel):
    id: int
    name: str
    email: str | None = None

FastAPI Implementation (functions.py)

from __future__annotations

from fastapi import FastAPI

from .models import UserModel

app = FastAPI()

@app.get("/users/{user_id}")
async def get_user(user_id: int) -> UserModel:
    ...

Asyncapi documentation (asyncapi.yaml)

asyncapi: 3.0.0
info:
  title: Zen
  version: 0.0.1
  description: ''
channels:
  get_user:
    $ref: '#/components/channels/get_user'
operations:
  get_user:
    $ref: '#/components/operations/get_user'
components:
  channels:
    get_user:
      messages:
        request:
          $ref: '#/components/messages/get_user_request'
        response:
          $ref: '#/components/messages/get_user_response'
  operations:
    get_user:
      action: receive
      description: ''
      channel:
        $ref: '#/channels/get_user'
      messages:
      - $ref: '#/channels/get_user/messages/request'
      reply:
        channel:
          $ref: '#/channels/get_user'
        messages:
        - $ref: '#/channels/get_user/messages/response'
  messages:
    get_user_request:
      title: Request params for get_user
      summary: ''
      description: ''
      payload:
        type: object
        required:
        - user_id
        properties:
          user_id:
            type: integer
            description: ''
    get_user_response:
      title: Response params for get_user
      summary: ''
      description: ''
      payload:
        $ref: '#/components/schemas/UserModel'
        format: required
  schemas:
    UserModel:
      type: object
      base_class: BaseModel
      required:
      - id
      - name
      properties:
        id:
          type: integer
        name:
          type: string
        email:
          type: string

Development Setup 🛠️

Requirements:

• Python 3.10+
• uv (Python packaging toolchain)

# Install uv if not already installed
# see https://docs.astral.sh/uv/getting-started/installation/

# Clone repository
git clone https://github.com/WaYdotNET/zen-generator.git
cd zen-generator

# Install dependencies with uv
uv sync

# Run tests
uv run pytest

Best Practices 💡

1. AsyncAPI Specification

   • Follow AsyncAPI 3.0 guidelines
   • Define clear schema types
   • Include comprehensive examples
   • Use semantic versioning

2. Code Generation

   • Review generated code for correctness
   • Implement business logic in function stubs
   • Keep generated files synchronized
   • Use type hints consistently

3. Project Organization

   • Maintain clear separation between models and functions
   • Follow standard Python package structure
   • Implement proper error handling

Contributing 🤝

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Submit a pull request

License 📄

MIT License - see LICENSE file for details

Support 💬

• GitHub Issues: Report bugs or suggest features

---

Made with ❤️ by WaYdotNET