Publish APIs¶

ShinyHub has managed launchers for FastAPI and Plumber. Declare the framework in shinyhub.toml; deployment, local development, wake, replicas and rollback read that declaration from the bundle. Existing apps retain their current launch behavior when framework is omitted.

FastAPI¶

Provide app.py exporting an ASGI application named app, and declare fastapi and uvicorn in requirements.txt or pyproject.toml:

[app]
framework = "fastapi"

ShinyHub prepares Python dependencies through the existing uv build path and starts uvicorn app:app on the replica's assigned host and port. Its external root path is set to /app/<slug>, including the separate slug of a draft preview. This keeps OpenAPI URLs and the /docs interface under the app's route. See FastAPI's proxy guide for the role of ASGI root_path.

cd examples/fastapi-demo
shinyhub dev .
shinyhub deploy . --slug calculations --open
# GET /app/calculations/add?a=2&b=3 returns {"result":5}
# Interactive documentation: /app/calculations/docs

Pin dependencies with your usual lockfile workflow for production. Host builds and off-host runtimes preserve the existing uv project/lockfile behavior.

Plumber¶

Provide plumber.R and make the plumber package available in your R project or runtime image:

[app]
framework = "plumber"

The launcher prepares R dependencies through the existing renv restore path, then runs plumber::pr_run(plumber::pr("plumber.R"), ...) with the assigned host and port. It preserves ShinyHub's R startup isolation and project-library policy. The OpenAPI server URL points to the app's external route. Interactive documentation is available at /app/<slug>/__docs__/.

cd examples/plumber-demo
# In R, initialize/snapshot the project's plumber dependency with renv.
shinyhub doctor .
shinyhub dev .
shinyhub deploy . --slug r-calculations --open

R execution requires R and the app dependencies on the selected runtime; R apps remain unsupported by the Python-only reference Fargate runner. See Plumber's server interface.

Readiness, access and drafts¶

Both managed API launchers probe /openapi.json by default, so an API does not need a GET / handler to become healthy. If OpenAPI is disabled or protected by application-level authentication, declare an internal readiness route:

[app]
framework = "fastapi"
readiness_path = "/healthz"
readiness_status = 200

deploy --open opens the root app URL. Provide a root handler if you want that flow, or open the documentation URL directly after deployment.

The normal public/shared/private access rules apply. Browser viewers sign in through ShinyHub. Platform API keys and trusted CI credentials manage deployment; they are not automatically credentials for the hosted API. Machine clients must use an appropriate ShinyHub login session or the API's own authentication on an intentionally public app. An app can use ShinyHub's verified forwarded identity; see Identity forwarding before making access decisions.

These APIs can use deployment drafts when their bundles contain no hooks, schedules or access-group declarations. Reviewers receive access to a separate preview; production data and credentials are not copied.

framework and a custom command are mutually exclusive. For different entrypoints or server options, use the existing explicit-command workflow. Session-based autoscaling remains session-based; HTTP request throughput does not become a new autoscaling signal just because the content is an API.