Deploy to GCP Cloud Run

The reflex cloud deploy --gcp command deploys a Reflex app to your own Google Cloud Run service.

The CLI fetches a Cloud Run-ready Dockerfile and deploy script, then submits the build through Cloud Build. Google Cloud stores the image in Artifact Registry and runs it on Cloud Run. The temporary deployment files do not modify your project tree.

Prerequisites

Before running the command, install and authenticate the local tools the deploy script invokes:

gcloud — install from the Google Cloud SDK docs, then run:

gcloud auth login
gcloud auth application-default login

docker — required by gcloud builds submit for source upload.
bash — used to run the deploy script.

You also need:

A GCP project with billing enabled. Without it, gcloud services enable fails with UREQ_PROJECT_BILLING_NOT_FOUND.
An Enterprise-tier Reflex Cloud subscription and a logged-in Reflex CLI (reflex login).

Quick start

From the root of your Reflex app:

The CLI will:

Authenticate with Reflex Cloud and fetch the deployment files.
Create a temporary cloudbuild.yaml.
Print the commands for review.
Ask for confirmation, then enable the required APIs, create the Artifact Registry repository, build the image, and deploy the Cloud Run service.
Delete the temporary file.

An existing Dockerfile in --source remains unchanged and is not used by this workflow.

When it's done, you'll get a service URL like https://my-reflex-app-<project-number>.us-central1.run.app.

Options

Option	Default	Description
`--gcp`	(required)	Selects the GCP Cloud Run target.
`--gcp-project`	(required)	The GCP project ID to deploy into. Project numbers are not accepted by `gcloud artifacts repositories`; use the project ID.
`--region`	`us-central1`	Cloud Run region.
`--service-name`	`reflex-app`	Cloud Run service name.
`--ar-repo`	`reflex`	Artifact Registry repository name (created on first deploy).
`--version`	UTC timestamp (`YYYYMMDD-HHMMSS`)	Image version tag.
`--source`	`.`	Directory containing the Reflex app. Uploaded to Cloud Build as the build context; the source tree itself is not modified.
`--token`	from `~/.reflex` config	Reflex authentication token.
`--interactive / --no-interactive`	`--interactive`	Whether to prompt before running the deploy script.
`--dry-run`	off	Print the manifest, the generated `cloudbuild.yaml`, and the rewritten script without writing the tempfile or running the script.
`--loglevel`	`info`	Log verbosity.

What gets created in your GCP project

The deploy script enables these APIs (if not already enabled):

cloudbuild.googleapis.com
run.googleapis.com
artifactregistry.googleapis.com

It then creates (idempotently) and uses:

An Artifact Registry Docker repository at ${REGION}-docker.pkg.dev/${GCP_PROJECT}/${AR_REPO}.
A Cloud Build job that builds and pushes the image.
A Cloud Run service named ${SERVICE_NAME}, deployed with --allow-unauthenticated, port 8080, 1 vCPU, 1 GiB memory, --min-instances 1, and --session-affinity.

Re-running the command pushes a new image tag and rolls the Cloud Run service forward.

How the build runs

The generated cloudbuild.yaml is a single Cloud Build step that:

Writes the Dockerfile into the build workspace via a single-quoted heredoc:

Builds and pushes the image, tagging it with _IMAGE (passed to gcloud builds submit as --substitutions=_IMAGE=...).

Because Cloud Build runs its own substitution pass over args, every literal $ in the Dockerfile is doubled to $$ before embedding (e.g. ENV PATH="${UV_PROJECT_ENVIRONMENT}/bin:$PATH" becomes ENV PATH="$${UV_PROJECT_ENVIRONMENT}/bin:$$PATH" in the YAML). Cloud Build's parser converts $$ back to $ before bash runs, so the Dockerfile written into the workspace contains the original characters.

Security model

The CLI runs the deploy script under a restricted environment. Only an explicit allowlist of host variables is forwarded to bash — things like PATH, HOME, CLOUDSDK_*, DOCKER_*, and proxy/TLS variables. Unrelated host secrets such as AWS_*, GITHUB_TOKEN, or arbitrary user variables are not forwarded, so a tampered or compromised manifest cannot exfiltrate them.

You can preview the rewritten script, generated cloudbuild.yaml, and Dockerfile before anything runs by using --dry-run:

Non-interactive use (CI)

For automated pipelines, pass --no-interactive and an explicit --token:

In non-interactive mode the CLI will not prompt, and it will exit non-zero if a token cannot be resolved.

Troubleshooting

Reflex denied the request (403). GCP Cloud Run deploys require an Enterprise tier subscription. Your account is not on the Enterprise tier. Contact [email protected].

Billing must be enabled for activation of service(s) ... (UREQ_PROJECT_BILLING_NOT_FOUND) Attach a billing account to the GCP project, or use a different --gcp-project.

The value of '--project' flag was set to Project number. To use this command, set it to PROJECT ID instead. Pass the project ID (e.g. my-app-123456), not the numeric project number.

No active GCP account found. Run gcloud auth login and gcloud auth application-default login.

The 'gcloud' / 'docker' / 'bash' CLI was not found on PATH. Install the missing tool and ensure it's on PATH for the shell you're invoking the CLI from.

Dockerfile content contains the reserved heredoc marker 'REFLEX_DOCKERFILE_EOF'. Vanishingly unlikely — the Dockerfile from Reflex Cloud happens to contain a line that exactly matches the heredoc terminator the CLI uses to embed it. Re-run after the next CLI release, or open an issue.

Couldn't find 'gcloud builds submit' in the deploy script. The CLI rewrites the gcloud builds submit block in the Reflex-supplied deploy script to use --config=. If Reflex Cloud changes the shape of that script before the CLI is updated to match, you'll see this error — upgrade reflex-hosting-cli (uv tool upgrade reflex-hosting-cli or pip install -U reflex-hosting-cli).