Generated application reference

modal-devin init writes an editable Modal application. Use the generator once, then maintain and deploy the generated file like other application code.

Worker and application

worker = Worker.from_env(
    "my-outpost",
    outpost_id="outpost_env-...",
    api_url="https://api.beta.devinenterprise.com",
)

app = modal.App(
    "modal-devin-my-outpost",
    tags={"service": "modal-devin"},
)
devin_secret = modal.Secret.from_name("devin-outposts-token")

The worker connects the deployment to one outpost. The Modal App name, tags, and Secret name belong to your deployment and may be changed.

Workspace image

base_image = (
    worker.base_image()
    # Add every application-specific build step here.
)

image = worker.prepare_image(base_image)

Add project tools and source before prepare_image(). New sessions start from this image; resumed sessions use their preserved filesystem when available.

Session entrypoint

@app.function(
    name="session",
    image=image,
    secrets=[devin_secret],
    timeout=worker.session_function_timeout_seconds,
)
def session(session_id: str) -> None:
    worker.run_session(
        session_id,
        app=app,
        image=image,
    )

Add Modal function retries only when you intentionally want failed invocations to make a fresh claim attempt. Customize the decorator using region controls. Pass supported Sandbox resource options such as CPU, memory, and region to run_session().

Scheduler entrypoint

@app.function(
    name="scheduler",
    image=controller_image,
    secrets=[devin_secret],
    schedule=modal.Period(seconds=worker.settings.scheduler_interval_seconds),
    max_containers=1,
)
def scheduler() -> None:
    worker.dispatch_pending_sessions(session.spawn)

Customize the schedule and its Modal placement policy. Keep its call structure and single-container limit unchanged.

Supported customization

You can change:

Application name, tags, and Modal Secret name.
Image build operations before prepare_image() and function resources, regions, retries, and schedule.
Supported Sandbox resource options in run_session().
Additional functions and resources in the same Modal application.

Required wiring

Keep these generated values in place:

Keep	User-visible reason
The Devin Secret on both functions	The deployment must authenticate while finding and serving sessions
`prepare_image()` after custom build steps	Later image operations are unsupported
The same prepared `image` in the decorator and `run_session()`	New sessions must start from the image you deployed
`max_containers=1` on the scheduler	Prevents duplicate scheduling races
`session.spawn` passed to the dispatcher	Allows sessions to start independently
Lifecycle exceptions propagating	Modal must record failed attempts accurately
Managed command, timeout, work directory, and readiness options	Recovery and cleanup depend on them

Keep the deployment scheduled while relying on long-lived resumability.

Tutorials

How-to guides

Concepts

Reference

Generated application reference

Worker and application

Workspace image

Session entrypoint

Scheduler entrypoint

Supported customization

Required wiring

​Worker and application

​Workspace image

​Session entrypoint

​Scheduler entrypoint

​Supported customization

​Required wiring

Worker and application

Workspace image

Session entrypoint

Scheduler entrypoint

Supported customization

Required wiring