Monitor a file for changes and send an alert

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Important notice

This workflow is provided as-is. Please review and test before using in production.

1. Workflow Overview

This flow monitors a file for changes of its content. If changed, an alert is sent out and you receive it as push, SMS or voice call on SIGNL4. User cases: Log file monito...

Best for

DevOps automation workflows
intermediate n8n builders looking for reusable templates

Tools used

n8n-nodes-base.cron, n8n-nodes-base.writebinaryfile, n8n-nodes-base.readbinaryfile, n8n-nodes-base.movebinarydata, n8n-nodes-base.function, n8n-nodes-base.if, n8n-nodes-base.signl4

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by Ron.

Original n8n.io source

1.1 Workflow description

Title: Monitor a file for changes and send an alert
Workflow name: Monitor a file for changes and send an alert

This flow monitors a file for changes of its content. If changed, an alert is sent out and you receive it as push, SMS or voice call on SIGNL4.

User cases:

Log-file monitoring
Monitoring of production data
Integration with third-party systems via file interface
Etc.

Sample file "alert-data.json":

{
    "Body": "Alert in building A2.",
    "Done": false,
    "eventId": "2518088743722201372_4ee5617b-2731-4d38-8e16-e4148b8fb8a0"
}

Body: The alert text to be sent. Done: If false this is a new alert. If true this indicated the alert has been closed. eventId: Last SIGNL4 event ID written by SIGNL4.

This flow can be easily adapted for database monitoring as well.

1.2 Logical Blocks

This catalog entry is organized from the workflow JSON. The node-level section below shows the executable blocks available for review before importing the template.

2. Block-by-Block Analysis

Block 1 - Cron

Type / Role: n8n-nodes-base.cron - cron
Config choices: Version 1

Block 2 - Write Binary File

Type / Role: n8n-nodes-base.writeBinaryFile - writeBinaryFile
Config choices: Version 1

Block 3 - Read Binary File

Type / Role: n8n-nodes-base.readBinaryFile - readBinaryFile
Config choices: Version 1

Block 4 - Binary to JSON

Type / Role: n8n-nodes-base.moveBinaryData - moveBinaryData
Config choices: Version 1

Block 5 - JSON to Binary

Type / Role: n8n-nodes-base.moveBinaryData - moveBinaryData
Config choices: Version 1

Block 6 - Mark as Done

Type / Role: n8n-nodes-base.function - function
Config choices: Version 1

Block 7 - IF

Type / Role: n8n-nodes-base.if - if
Config choices: Version 1

Block 8 - SIGNL4 Resolve

Type / Role: n8n-nodes-base.signl4 - signl4
Config choices: Version 1

Block 9 - SIGNL4 Alert

Type / Role: n8n-nodes-base.signl4 - signl4
Config choices: Version 1

3. Summary Table

Workflow	Monitor a file for changes and send an alert
Complexity	intermediate
Nodes	9
Categories	DevOps
Author	Ron
Published	03 Mar 2021

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/967/967.json as the source template for this automation.
2. Import the template into n8n

Open n8n, import the downloaded JSON, and review each node before activating the workflow.
3. Configure credentials and variables

Replace placeholder credentials, API keys, webhook URLs, account IDs, and environment-specific values with your own settings.
4. Test with sample data

Run the workflow manually or in a staging workspace, inspect node output, and confirm downstream systems receive the expected data.
5. Activate and monitor

Enable the workflow only after testing, then monitor executions, errors, and rate limits during the first production runs.

5. General Notes & Resources

Review imported nodes carefully before activation. This catalog entry is intended to help you inspect the workflow structure, understand required services, and find related templates faster.

Node names, credentials, schedules, webhook paths, and external service limits may need adjustment for your workspace.

Download workflow JSON Original n8n.io source DevOps workflows

Frequently asked questions

What does Monitor a file for changes and send an alert do?

This flow monitors a file for changes of its content. If changed, an alert is sent out and you receive it as push, SMS or voice call on SIGNL4. User cases: Log file monito...

What do I need before importing this workflow?

Review the workflow JSON, configure any required credentials in n8n, and test the automation in a safe workspace before using it in production.

Can I customize this workflow?

Yes. Use the block-by-block analysis and the downloadable JSON to inspect each node, then adjust credentials, prompts, schedules, filters, or destinations for your DevOps use case.

Ron

4 workflows

Nodes

n8n-nodes-base.cron n8n-nodes-base.writebinaryfile n8n-nodes-base.readbinaryfile n8n-nodes-base.movebinarydata n8n-nodes-base.function n8n-nodes-base.if n8n-nodes-base.signl4

Complexity

intermediate

Published 03 Mar 2021

Likes 0

View on n8n.io Download Workflow

Install path: /data/workflows/967/967.json

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Monitor a file for changes and send an alert

Workflow preview

Important notice

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Cron

Block 2 - Write Binary File

Block 3 - Read Binary File

Block 4 - Binary to JSON

Block 5 - JSON to Binary

Block 6 - Mark as Done

Block 7 - IF

Block 8 - SIGNL4 Resolve

Block 9 - SIGNL4 Alert

3. Summary Table

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

2. Import the template into n8n

3. Configure credentials and variables

4. Test with sample data

5. Activate and monitor

5. General Notes & Resources

Frequently asked questions