zynk 0.1.3

Python server runtime for Zynk. Pair with the standalone `zynk` CLI (zynk-cli) for type-safe TypeScript client generation.

Zynk

Python server runtime for Zynk -- a general-purpose command protocol for building type-safe bridges between backends and frontends.

Install

pip install zynk

The zynk CLI is bundled in platform wheels. If no prebuilt binary is available for your platform, install the standalone CLI with:

cargo install zynk-cli

Quick start

from pydantic import BaseModel
from zynk import Bridge, command

class User(BaseModel):
    id: int
    name: str
    email: str

@command
async def get_user(user_id: int) -> User:
    return User(id=user_id, name="Alice", email="[e-mail]")

bridge = Bridge(title="Users API", port=8000)

if __name__ == "__main__":
    bridge.run(dev=True)

Generate a TypeScript client:

zynk gen typescript --target python --app main:bridge --out ./frontend/src/generated

Use it from the frontend:

import { initBridge, getUser } from "./generated/api";

initBridge("http://127.0.0.1:8000");

const user = await getUser({ userId: 123 });
console.log(user.name);

Features

Commands (request/response)

from zynk import command

@command
async def greet(name: str) -> str:
    return f"Hello, {name}!"

Channels (server-streamed values)

import asyncio
from zynk import command, Channel

@command
async def stream_data(channel: Channel[dict]) -> None:
    for i in range(10):
        await channel.send({"value": i})
        await asyncio.sleep(0.1)

WebSockets (bidirectional)

from pydantic import BaseModel
from zynk import message, WebSocket

class ChatMessage(BaseModel):
    text: str

class ServerEvents:
    chat_message: ChatMessage

class ClientEvents:
    chat_message: ChatMessage

@message
async def chat(ws: WebSocket[ServerEvents, ClientEvents]) -> None:
    @ws.on("chat_message")
    async def on_message(data: ChatMessage):
        await ws.send("chat_message", data)

    await ws.listen()

File uploads

from pydantic import BaseModel
from zynk import upload, UploadFile

class UploadResult(BaseModel):
    filename: str
    size: int

@upload(max_size="10MB", allowed_types=["image/*", "application/pdf"])
async def upload_file(file: UploadFile) -> UploadResult:
    content = await file.read()
    return UploadResult(filename=file.filename, size=file.size)

Static files

from zynk import static, StaticFile

@static
async def user_avatar(user_id: str) -> StaticFile:
    return StaticFile.from_directory(base_dir="./avatars", filename=f"{user_id}.png")

How it works

Zynk defines a stable wire protocol (HTTP + SSE + WebSocket with JSON envelopes). The Python package provides the server runtime (Bridge, decorators, type extraction), and the zynk CLI reads the schema IR to generate type-safe clients in TypeScript or Effect-TS.

Any generated client works with any conforming host -- a TypeScript client generated from a Python host works unchanged against a Rust Axum host.

Links

• Repository
• Rust crates
• CLI (cargo install zynk-cli)

License

MIT