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GuideReference

Overview

Introduction Example: Hello, world Tutorial: A simple web scraper

Custom container images

Custom container images Private registries

GPUs and other resources

GPU acceleration Reserving CPU and memory Example: Run a 40-billion parameter LLM (Falcon-40B)

Scaling out

Scaling out Example: Face detection on YouTube videos

Secrets and environment variables

Secrets Example: Write to Google Sheets

Deployment

Managing deployments Invoke deployed functions

Scheduling and cron jobs

Scheduling remote cron jobs Example: Hacker News Slackbot

Web endpoints

Web endpoints Streaming web endpoints Web endpoint URLs Request timeouts Example: Document OCR job queue Example: Document OCR web app

Sharing data

Passing local data Shared volumes

Deep learning and AI examples

Fast Stable diffusion Replace your CEO with an LLM Voice Chat with LLMs Parallel podcast transcription using Whisper Pet Art using Dreambooth Question-answering with LangChain Play with ControlNet Misc examples

Examples using popular libraries

DuckDB: Analyze NYC taxi data in parallel Blender: Distributed 3D rendering SQLite: Publish explorable data with Datasette Y! Finance: Stock prices in parallel

Reliability and robustness

Failures and retries Preemption Timeouts Troubleshooting

Security

Security at Modal

Other topics

Developing and debugging Cold start performance Workspaces Notebooks support Asynchronous usage Global variables Container lifecycle and parameters Apps, stubs, and entrypoints Useful snippets Example: Algolia docsearch crawler

Notebooks support

Known issues

Modal can be used in a notebook environment, such as Jupyter Notebooks, but there are some limitations to be aware of.

Modal functions and app must be defined and executed within a single notebook cell.

Currently you cannot spread your Modal functions and stub.run() app execution across multiple cells. Code from other cells can be referred to, but all @stub.function() decorations should be in a single cell.

Modal functions can only be called remotely. Invoking the wrapped function locally does not work.

@stub.function()
def f():
    return "hello"

with stub.run():
    assert "hello" == f.call()  # remote call works ✔️
    f()  # raises error in notebook ⚠️

Interactive shell and interactive functions are not yet supported. Notebook environments require special handling of REPL terminal functionality which is not yet implemented.

If you encounter issues not documented above, first check your Modal client version is >=0.49.2142. Also, try restarting the notebook kernel, as the kernel state may be in a broken state, a common problem in notebook development.

If the issue persists, contact us in Slack.

We are working on removing these limitations so that writing Modal applications in a notebook feels just like developing in regular Python modules and scripts.

Further examples