n8n-nodes-gcp-pubsub

This is an n8n community node that provides integration with Google Cloud Pub/Sub messaging service. It allows you to publish and subscribe to messages using Pub/Sub topics and subscriptions in your n8n workflows.

Google Cloud Pub/Sub is a messaging service for exchanging event data among applications and services. It provides reliable, many-to-many, asynchronous messaging between applications.

n8n is a fair-code licensed workflow automation platform.

Table of Contents

• Installation
• Nodes
  • GCP Pub/Sub Publisher
  • GCP Pub/Sub Subscriber
• Credentials
• Compatibility
• Usage
• Resources

Installation

Follow the installation guide in the n8n community nodes documentation.

1. Go to Settings > Community Nodes.
2. Select Install.
3. Enter n8n-nodes-gcp-pubsub in Enter npm package name.
4. Agree to the risks of using community nodes: select I understand the risks of installing unverified code from a public source.
5. Select Install.

After installing the node, you can use it like any other node. n8n displays the node in search results in the Nodes panel.

Nodes

This package contains two nodes for working with Google Cloud Pub/Sub:

GCP Pub/Sub Publisher

The Publisher node allows you to publish messages to a Pub/Sub topic.

Parameters

• Project ID (required): The Google Cloud Project ID where your Pub/Sub topic exists
• Topic Name (required): The name of the Pub/Sub topic to publish messages to

Features

• Publishes the entire input data as JSON to the specified topic
• Returns the message ID upon successful publication
• Supports error handling with continue on fail option
• Can be used as a tool in AI workflows

Input/Output

• Input: Any JSON data that you want to publish to the topic
• Output: Original data plus a result object containing:
  • success: boolean indicating if the message was published successfully
  • messageId: the unique identifier of the published message

GCP Pub/Sub Subscriber

The Subscriber node is a trigger node that listens for messages from a Pub/Sub subscription.

Parameters

• Project ID (required): The Google Cloud Project ID where your Pub/Sub subscription exists
• Subscription Name (required): The name of the Pub/Sub subscription to listen to

Features

• Continuously listens for messages from the specified subscription
• Automatically acknowledges messages after processing
• Handles both JSON and text message payloads
• Provides comprehensive message metadata

Output

Each received message outputs:

• id: The unique message ID
• attributes: Message attributes (key-value pairs)
• data: The message payload (parsed as JSON if possible, otherwise as string)
• publishTime: When the message was published
• received: Timestamp when the message was received by the node

Credentials

Both nodes require Google Cloud Platform Service Account credentials to authenticate with the Pub/Sub service.

Setting up GCP Service Account

1. Create or select a Google Cloud Project:

   • Go to the Google Cloud Console
   • Select an existing project or create a new one

2. Enable the Pub/Sub API:

   • In the Cloud Console, go to APIs & Services > Library
   • Search for "Cloud Pub/Sub API" and enable it

3. Create a Service Account:

   • Go to IAM & Admin > Service Accounts
   • Click Create Service Account
   • Enter a descriptive name (e.g., "n8n-pubsub-service-account")
   • Add a description for clarity

4. Grant necessary permissions:
   Choose one of these permission sets based on your needs:

   • Pub/Sub Admin (for full access to all Pub/Sub resources)
   • Pub/Sub Editor (for read/write access)
   • Or create a custom role with specific permissions:
     • pubsub.topics.publish (for Publisher node)
     • pubsub.subscriptions.consume (for Subscriber node)
     • pubsub.messages.ack (for message acknowledgment)

5. Generate and download the key:

   • Select your service account
   • Go to the Keys tab
   • Click Add Key > Create new key
   • Select JSON format
   • Download the key file

6. Configure credentials in n8n:

   • In n8n, go to Settings > Credentials
   • Click Create New Credential
   • Select Google Cloud Platform Service Account API
   • Copy the entire contents of the downloaded JSON file
   • Paste it into the Service Account JSON field
   • Save the credential

Example Service Account JSON Structure

{
  "type": "service_account",
  "project_id": "your-project-id",
  "private_key_id": "key-id",
  "private_key": "-----BEGIN PRIVATE KEY-----\n...\n-----END PRIVATE KEY-----\n",
  "client_email": "service-account@your-project-id.iam.gserviceaccount.com",
  "client_id": "client-id",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/service-account%40your-project-id.iam.gserviceaccount.com"
}

Security Best Practices

• Store the service account JSON securely and never commit it to version control
• Use the principle of least privilege (only grant necessary permissions)
• Regularly rotate service account keys
• Monitor service account usage in the Cloud Console
• Consider using Workload Identity in production environments

Compatibility

• Minimum n8n version: 1.0.0
• Tested with: n8n v1.0.0+
• Node API version: 1
• Dependencies: @google-cloud/pubsub v5.2.0+

Usage

Basic Publisher Example

1. Add a Manual Trigger or any input node
2. Add the GCP Pub/Sub Publisher node
3. Configure the Project ID and Topic Name
4. Select your GCP Service Account credentials
5. The node will publish whatever data flows into it

Basic Subscriber Example

1. Add the GCP Pub/Sub Subscriber trigger node
2. Configure the Project ID and Subscription Name
3. Select your GCP Service Account credentials
4. The workflow will trigger whenever a message is received

Advanced Usage

Message Processing Pipeline:

Subscriber → Process Data → Publisher

Error Handling:
Enable "Continue on Fail" in the Publisher node to handle publishing errors gracefully.

Message Attributes:
The Subscriber node provides access to message attributes, which can be used for routing or filtering logic.

Prerequisites

Before using these nodes, ensure you have:

• A Google Cloud Platform account with billing enabled
• A project with the Pub/Sub API enabled
• At least one Pub/Sub topic and subscription created
• Proper IAM permissions configured

To create topics and subscriptions, you can use the Google Cloud Console or the gcloud CLI tool.

Resources

• n8n community nodes documentation
• Google Cloud Pub/Sub documentation
• Google Cloud Service Accounts
• Pub/Sub Node.js client library