[GAS] Stop Just Pushing: Automate Web App Releases with ‘clasp deploy’

Many developers use clasp for Google Apps Script (GAS) development, but most stop at clasp push.

I used to be one of them, until I realized that clasp deploy allows you to create deployments and get Deployment IDs entirely from the CLI.

Stop clicking the "New Deployment" button in your browser. It's time to automate.

What clasp deploy Can Do

Essentially, it performs the same action as the "New Deployment" button in the GAS editor, but from your terminal.

1. Create a new Deployment (Production environment).
2. Retrieve the Deployment ID immediately.
3. Publish a versioned snapshot.

Basic Commands

# Upload your code
clasp push

# Create a new version (Snapshot)
clasp version "Ver 1.0.0 Release"

# Deploy that specific version
clasp deploy -V 1 -d "Initial Deploy"

Just like that, a new Web App URL or API endpoint is generated instantly.

Does the Web App URL Change?

This is the most critical point.

clasp deploy = Create NEW (URL Changes)

Every time you run clasp deploy, a new Deployment ID is generated. This means your Web App URL (…/exec) will change every time.

• Use Case: Creating disposable test environments or issuing unique URLs for different clients.

clasp redeploy = UPDATE (URL Stays)

If you want to keep the existing Web App URL but update the content to a new version, use clasp redeploy.

# Update an existing deployment ID to a new version
clasp redeploy <DeploymentID> -V <NewVersionNumber>

If you don't use this, you'll end up in dependency hell, having to notify your users of a new URL every time you fix a bug.

Practical Workflow

Here is the robust workflow for CLI-only management:

1. Initial Deployment (Issue URL)

clasp push
clasp version "First Release"
clasp deploy -V 1 -d "Production"
# Write down the Deployment ID output here!

2. Update Deployment (Keep URL)

clasp push
clasp version "fix bug"
# → Created version 2

# Apply Version 2 to the existing ID
clasp redeploy <DeploymentID> -V 2

Don't Forget appsscript.json

To publish as a Web App, defining the webapp configuration in your local appsscript.json is mandatory before deploying.

{
  "timeZone": "Asia/Tokyo",
  "dependencies": {},
  "webapp": {
    "access": "ANYONE",
    "executeAs": "USER_DEPLOYING"
  },
  "exceptionLogging": "STACKDRIVER"
}

With this, the moment you run clasp deploy, a publicly accessible Web App is born.

Summary

• 【Conclusion】Don't just push. Use version → deploy to fully automate releases.
• 【Caution】clasp deploy generates a new URL every time. Use clasp redeploy to keep the same URL.
• 【Point】Manage Web App settings (permissions) via appsscript.json.

This opens up the possibility of full CI/CD pipelines for your Google Apps Script projects!