Modulith

Build once. Deploy effortlessly. Run everywhere

Modulith lets you focus on your application logic, not deployment infrastructure. Structure your code as modules with defined capabilities, then serve or deploy them on any machine without worrying about the underlying infrastructure. Whether you're running locally for development or scaling across the cloud, your interface stays consistent and your modules remain reusable.

🚀 What You Get

• 🧱 Scalable by design — move from local → distributed seamlessly
• 🔗 Composable — build systems by combining modules, local or remote
• 🌐 Shareable — publish and reuse modules across projects
• 🔐 Built-in access control — rate limits, burst limits, auth tokens

📦 Install

pip install modulith

🚀 Quick Start

Define a module and run it locally:

# calculator/module.py
from modulith import Modulith

module = Modulith("calculator")

@module.capability("add")
def add(a: float, b: float) -> float:
    return a + b

result = module.add(a=1, b=2) # → 3

🐳 Deploy effortlessly

Modulith abstracts away deployment complexity. With a single command, you can deploy your module with built-in access controls, monitoring, automatic scaling. Let's you fully focus on your application logic, not the underlying infrastructure:

modulith deploy 
--source calculator.module \    
--public \                     
--rate-limit 100 \             
--burst-limit 20 

You'll see:

🔑 Your authentication token: ...

🌐 Module 'calculator' is live:
- Repository: <your_username>/calculator
- Public URL: ...

⚙️ Capabilities:
- add(a: float, b: float) → float

⚡ Public access limits:
- Rate limit: 100 requests/minute
- Burst limit: 20 requests

🌐 Run Everywhere

Now you can access your module from any machine:

calculator = Modulith.remote(
    "<your_username>/calculator",
    access_token="..."
)
result = calculator.add(a=1, b=2) # → 3 (executed remotely)

Same interface. Local or remote, no difference.

🔗 Composing Modules

Build new modules on top of existing modules:

new_module = Modulith()
calculator = Modulith.remote("<your_username>/calculator", access_token="...")

@new_module.capability("double_sum")
def double_sum(a: float, b: float) -> float:
    sum1 = calculator.add(a, b)
    sum2 = calculator.add(a, b)
    return sum1 + sum2

result = new_module.double_sum(a=1, b=2) #  → 6

Execution flow:

double_sum(1, 2)
  → add(1, 2)   [remote]  → 3
  → add(1, 2)   [remote]  → 3
  → 3 + 3                 → 6

👤 Account (Optional)

Skip manual token management by linking modules to your account:

modulith signup # Create an account
modulith login

Once logged in, your module is automatically registered under your username:

🌐 Module 'calculator' is live:
- Repository: <your_username>/calculator
...

CLI Reference