Securely call Google Cloud Run APIs with service account auth (main-workflow)

Who it’s for? Anyone who wants a simple, secure way to call a Google Cloud Run endpoint from n8n—without exposing it publicly. People who want a cheap/free-tier way to run custom API logic without hosting n8n or spinning up servers. Example: you’ve got scraping code that needs specific system/python libs—build it into a Dockerfile on Cloud Run, then call it as a secure endpoint from n8n. How it works This is a conjunctive workflow: the main workflow calls Service Auth (sub-workflow) to get a Google ID token, merges that auth with your context, then calls your Cloud Run URL with Authorization: Bearer <idtoken>. Works great for single calls or looping over items. How to set up General instructions below—see my detailed guide for more info: Build a Secure Google Cloud Run API, Then Call It from n8n (Free Tier) Setup: 1. Create a Cloud Run service and enable Require authentication (Cloud IAM). 2. Create a Google Service Account and grant Cloud Run Invoker on that service. 3. In n8n, import the workflows and update the Vars node (serviceurl, optional servicepath). 4. Create a JWT (PEM) credential from your service account key, then run. 5. Make sure to read the sticky notes in the workflows—they contain helpful pointers and optional configurations. Requirements - Cloud Run service URL (auth required) - Google Service Account with Cloud Run Invoker - Private key JSON fields downloaded from Service Account | needed to generate JWT credentials How to customize Change the HTTP method/path/body in Cloud Run Request, or drop the Service Auth (sub-workflow) into other workflows to reuse the same auth pattern. More details Full write-up (minimal + modular flows), screenshots, and more: Build a Secure Google Cloud Run API, Then Call It from n8n (Free Tier) — by Marco Cassar