Data & databasesCodeGmailGoogle SheetsIfItem Lists

Material Issue Request and Approval

Configured with Gmail, Google Sheets, Item Lists, Supabase, and additional nodes. Review the connections and setup before adapting this template.

Download workflow JSON View files on GitHub ↗48 nodes · MIT

Workflow preview

Node categories in this workflow

Data store
Trigger
Transform
Code
Messaging
Routing

Icons describe general node roles, inferred from node types. Inspect the parameters for the configured action.

Drag to pan; use + and − to zoom. Reconstructed from the exported node positions; nothing runs here. Dashed lines represent non-main connections. Full node names and notes appear below.

How it works

The exported workflow contains the following configured nodes. Their connections are shown above; inspect the JSON for the complete logic, expressions, and external actions.

Workflow node names, types, and operations
Node	Category	Type	Operation
Append Material Request	Data store	Google Sheets	append
Get Approvals	Trigger	Webhook	See node parameters
Standardize Data	Transform	Edit Fields	See node parameters
Update Stock	Code	Code	See node parameters
Receive Issue Request	Trigger	Webhook	See node parameters
Send Approval Request	Messaging	Gmail	See node parameters
Prepare Approval	Code	Code	See node parameters
Create Record Issue	Data store	Supabase	See node parameters
Search Product ID	Data store	Supabase	getAll
Searck Issues	Data store	Supabase	getAll
Update Current Stck	Data store	Supabase	update
Merge Lookups	Transform	Merge	See node parameters
Update Current Stock1	Data store	Google Sheets	update
LookUp Current stock1	Data store	Google Sheets	See node parameters
Low stock Detection1	Code	Code	See node parameters
Merge1	Transform	Merge	See node parameters
Append Raw Materials	Data store	Google Sheets	append
Calculate Total Price	Code	Code	See node parameters
Calculate Updated Current Stock	Code	Code	See node parameters
Validate Quantity Received	Code	Code	See node parameters
Initialize New Product stock	Data store	Google Sheets	append
Update Current Stock	Data store	Google Sheets	update
LookUp Current stock	Data store	Google Sheets	See node parameters
New Row Current Stock	Data store	Supabase	See node parameters
Current Stock Update	Data store	Supabase	update
Search Current Stock	Data store	Supabase	getAll
Format response	Transform	Item Lists	removeDuplicates
Merge	Transform	Merge	See node parameters
Low stock Detection2	Code	Code	See node parameters
Receive Raw Materials Webhook	Trigger	Webhook	See node parameters
Standardize Raw Material Data	Transform	Edit Fields	See node parameters
Lookup Existing Stock	Data store	Google Sheets	See node parameters
Check If Product ID Exists	Routing	If	See node parameters
New Record Row	Data store	Supabase	See node parameters
Trigger Low Stock Alert	Routing	If	See node parameters
Send Low Stock Email Alert	Messaging	Gmail	See node parameters
Low Stock Email Alert	Messaging	Gmail	See node parameters
Validate Issue Request Data	Code	Code	See node parameters
Verify Requested Quantity	Code	Code	See node parameters
Check Available Stock for Issue	Data store	Google Sheets	See node parameters
Format Approval Response	Transform	Edit Fields	See node parameters
Verify Approval Data	Code	Code	See node parameters
Retrieve Issue Request Details	Data store	Google Sheets	See node parameters
Process Approval Decision	Routing	If	See node parameters
Get Stock for Issue Update from Current	Data store	Google Sheets	See node parameters
Update Stock After Issue	Data store	Google Sheets	update
Materials Issue Table Update	Data store	Supabase	update
Is Stock is Low	Routing	If	See node parameters

Setup

Download the JSON and import it into an isolated n8n instance. Leave the workflow inactive.
Connect your own credentials through n8n’s credential store. Replace REPLACE_WITH_* values with your resource identifiers.
Inspect API destinations, Code nodes, database queries, file paths, and outbound actions.
Run with synthetic data and harmless destinations. Enable triggers only after checking the actual outputs.

Requirements

An n8n instance with the listed node types and compatible versions. Service-connected workflows may require accounts, credentials, or paid APIs.

Credential types declared in the source

None declared. HTTP requests and Code nodes may still need configuration.

Workflow notes

Raw Materials Inventory Management with Google Sheets and Supabase using n8n Webhooks

Introduction

This n8n automation streamlines raw materials inventory management by automating the receipt of materials, issuing materials upon approval, updating stock levels, and sending low stock alerts. It integrates webhooks, Google Sheets, Supabase, and Gmail to ensure efficient inventory tracking and communication.

Problem Statement

Manual inventory management is time-consuming and error-prone, often leading to stock discrepancies, delayed approvals for material issuance, and missed low stock alerts. This automation addresses these issues by providing a seamless workflow for receiving raw materials, processing issue requests, and monitoring stock levels in real time.

Target Audience

This template is designed for:

Small to medium-sized businesses managing raw materials inventory.
Inventory managers seeking to automate stock updates and approvals.
n8n users familiar with Google Sheets, Supabase, and Gmail integrations.

Description

Flow 1: Raw Materials Receiving and Stock Update

Purpose: Automates the receipt of raw materials, calculates costs, updates stock, and sends low stock alerts.

Receive Raw Materials Webhook
- Purpose: Receives raw material data via HTTP POST at a webhook URL from a form submission.
- Input: JSON with fields like product_id, quantity_received, unit_price, submitted via a form (e.g., Google Form or custom form).
- Output: Raw webhook data.
- Notes: Expects Content-Type: application/json.
Standardize Raw Material Data
- Purpose: Maps webhook data into a consistent format.
- Input: Webhook JSON from form submission.
- Output: JSON with fields like Timestamp, Product ID, Quantity Received.
- Notes: Aligns field names for downstream nodes.
Calculate Total Price
- Purpose: Computes total cost and validates numeric inputs.
- Input: Standardized JSON.
- Output: JSON with Total Price (Quantity Received * Unit Price).
- Notes: Uses a custom function to handle invalid numbers.
Append Raw Materials
- Purpose: Records the receipt in Google Sheets.
- Input: Calculated JSON.
- Output: Updated "Raw Materials" sheet with new record.
- Notes: Requires Google Sheets credentials (to be configured by the user).
Check Quantity Received Validity
- Purpose: Ensures Quantity Received is a positive number.
- Input: JSON from Append Raw Materials.
- Output: Validated JSON with numeric Quantity Received.
- Notes: Throws error if invalid.
Lookup Existing Stock
- Purpose: Retrieves existing stock for the Product ID.
- Input: Validated JSON.
- Output: JSON with Current Stock from "Current Stock" sheet.
- Notes: Google Sheets lookup by Product ID.
Check If Product Exists
- Purpose: Branches based on whether the Product ID exists in stock.
- Input: JSON from Lookup Existing Stock.
- Output: True/False branch.
- Notes: Condition checks for Product ID existence.
Calculate Updated Current Stock (True Branch)
- Purpose: Updates stock by adding Quantity Received.
- Input: JSON with existing stock.
- Output: JSON with Updated Current Stock.
- Notes: Ensures numeric accuracy.
Update Current Stock (True Branch)
- Purpose: Updates the "Current Stock" sheet with new stock.
- Input: Updated stock JSON.
- Output: Updated "Current Stock" sheet.
- Notes: Matches by Product ID.
Retrieve Updated Stock for Check (True Branch)
- Purpose: Retrieves updated stock for low stock check.
- Input: Updated stock JSON.
- Output: JSON with current stock data.
- Notes: Google Sheets lookup.
Detect Low Stock Level (True Branch)
- Purpose: Flags if stock falls below the minimum level.
- Input: Retrieved stock data.
- Output: JSON with Is Low flag and Alert Message.
- Notes: Compares with Minimum Stock Level (default: 50).
Trigger Low Stock Alert (True Branch)
- Purpose: Triggers notification if stock is low.
- Input: Low stock detection JSON.
- Output: True branch sends email.
- Notes: Condition: {{ $json['Is Low'] }}.
Send Low Stock Email Alert (True Branch, Low)
- Purpose: Sends low stock alert email to the stock manager.
- Input: JSON with alert details.
- Output: HTML email to a user-configured email address.
- Notes: Includes product info and reorder link; email address must be set by the user.
Add New Product to Stock (False Branch)
- Purpose: Adds new product to "Current Stock" sheet.
- Input: Validated JSON.
- Output: New row with initial stock (Quantity Received).
- Notes: Sets Minimum Stock Level to 50.
Current Stock Update (True Branch, Supabase)
- Purpose: Updates Supabase Current Stock table.
- Input: Updated stock JSON.
- Output: Updated Supabase record.
- Notes: Matches by Product ID; requires user-configured Supabase credentials.
New Row Current Stock (False Branch, Supabase)
- Purpose: Inserts new product into Supabase Current Stock table.
- Input: Validated JSON.
- Output: New Supabase record.
- Notes: Sets initial stock; requires Supabase credentials.
Search Current Stock (Supabase)
- Purpose: Retrieves Current Stock records for Product ID.
- Input: JSON with Product ID.
- Output: JSON array of matching records.
- Notes: Uses returnAll: true.
New Record Raw (Supabase)
- Purpose: Inserts raw material record into Supabase Raw Materials table.
- Input: Calculated JSON.
- Output: New Supabase record.
- Notes: Auto-maps input data.
Format Response
- Purpose: Removes duplicates from response.
- Input: Search Current Stock data.
- Output: Cleaned JSON array.
- Notes: Ensures unique records.
Combine Stock Update Branches
- Purpose: Combines branches (existing/new product).
- Input: Outputs from Check If Product Exists branches.
- Output: Merged JSON.
- Notes: Ensures data continuity.

Impact: Automates raw material receipt, ensures accurate stock updates, and provides timely low stock notifications.

Flow 2: Material Issue Request and Approval

Purpose: Automates material issue requests, processes approvals/rejections, updates stock, and sends low stock alerts.

Receive Material Issue Webhook
- Purpose: Receives material issue request via HTTP POST at a webhook URL from a form submission.
- Input: JSON with Product ID, Quantity Requested, etc., submitted via a form (e.g., Google Form or custom form).
- Output: Raw webhook data.
- Notes: Webhook trigger for issue requests.
Standardize Data
- Purpose: Normalizes request data and generates approval link.
- Input: Webhook JSON from form submission.
- Output: JSON with Status "Pending," Approval Link.
- Notes: Maps form fields for consistency.
Validate Issue Request Data
- Purpose: Ensures Quantity Requested is a positive number.
- Input: Standardized JSON.
- Output: Validated JSON or error.
- Notes: JavaScript validation.
Verify Requested Quantity
- Purpose: Validates additional fields like Product ID and Submission ID.
- Input: Validated JSON.
- Output: Further validated JSON or error.
- Notes: Ensures data integrity.
Append Material Request
- Purpose: Records request in "Materials Issued" sheet.
- Input: Verified JSON.
- Output: Updated "Materials Issued" sheet.
- Notes: Google Sheets append operation.
Check Available Stock for Issue
- Purpose: Retrieves Current Stock for Product ID.
- Input: Appended JSON.
- Output: JSON with stock data.
- Notes: Google Sheets lookup.

Approval Process

The following steps handle the approval of material issue requests, ensuring that requests are reviewed and either approved or rejected before stock is updated.

Prepare Approval
- Purpose: Checks if stock is sufficient to fulfill the request.
- Input: Stock data from Check Available Stock for Issue.
- Output: JSON with Is Enough flag (true if Current Stock >= Quantity Requested).
- Notes: Prepares data for the approval email.
Send Approval Request
- Purpose: Sends an email to the approver with clickable Approve/Reject buttons.
- Input: JSON with Is Enough, Product ID, Quantity Requested, and Approval Link.
- Output: HTML email to a user-configured email address.
- Notes: Email contains buttons linking to the Receive Approval Response webhook; email address must be set by the user.
Receive Approval Response
- Purpose: Captures the approver’s decision via a webhook triggered by clicking Approve/Reject.
- Input: Webhook parameters like submissionId, action ("approve" or "reject"), quantity.
- Output: Raw webhook data with approval details.
- Notes: Webhook URL must be configured to match the links in the approval email.
Format Approval Response
- Purpose: Processes the approval response and adds metadata.
- Input: Webhook JSON from Receive Approval Response.
- Output: JSON with Action, Approved Quantity, Approval Date.
- Notes: Sets Approval Date to the current timestamp.
Verify Approval Data
- Purpose: Validates the approval response to ensure it’s complete and correct.
- Input: Formatted JSON.
- Output: Validated JSON or error.
- Notes: Checks for valid Submission ID, Action, and Approved Quantity (> 0).
Retrieve Issue Request Details
- Purpose: Retrieves the original issue request for updating.
- Input: Validated JSON with Submission ID.
- Output: JSON with request data from "Materials Issued" sheet.
- Notes: Google Sheets lookup by Submission ID.
Process Approval Decision
- Purpose: Branches the flow based on the approver’s decision.
- Input: JSON with Action ("approve" or "reject").
- Output: True branch (approved) or False branch (rejected).
- Notes: Condition: {{ $json['Action'] === "approve" }}.

Post-Approval Steps

Get Stock for Issue Update (True Branch, Approved)
- Purpose: Retrieves the latest Current Stock before updating.
- Input: Approved JSON.
- Output: JSON with stock data.
- Notes: Google Sheets lookup.
Deduct Issued Stock (True Branch, Approved)
- Purpose: Reduces stock by Approved Quantity.
- Input: Stock and approval data.
- Output: JSON with Updated Current Stock.
- Notes: Errors if stock is insufficient.
Update Stock After Issue (True Branch, Approved)
- Purpose: Updates "Current Stock" sheet with new stock.
- Input: Updated stock JSON.
- Output: Updated "Current Stock" sheet.
- Notes: Matches by Product ID.
Retrieve Stock After Issue (True Branch, Approved)
- Purpose: Retrieves updated stock for low stock check.
- Input: Updated stock JSON.
- Output: JSON with stock data.
- Notes: Google Sheets lookup.
Detect Low Stock After Issue (True Branch, Approved)
- Purpose: Flags if stock is low after issuance.
- Input: Retrieved stock data.
- Output: JSON with Is Low flag and Alert Message.
- Notes: Compares with Minimum Stock Level.
Trigger Low Stock Alert After Issue (True Branch, Approved)
- Purpose: Triggers notification if stock is low.
- Input: Low stock detection JSON.
- Output: True branch sends email.
- Notes: Condition: {{ $json['Is Low'] }}.
Send Low Stock Email After Issue (True Branch, Low)
- Purpose: Sends low stock alert email.
- Input: JSON with alert details.
- Output: HTML email to a user-configured email address.
- Notes: Includes product info; email address must be set by the user.
Update Issue Request Status (True/False Branch)
- Purpose: Updates request status in "Materials Issued" sheet.
- Input: Approval action JSON.
- Output: Updated sheet with Status "Approved" or "Rejected."
- Notes: Google Sheets update; includes Approved By and Approval Date if approved.
Combine Stock Lookup Results
- Purpose: Combines stock lookup branches.
- Input: Outputs from Check Available Stock for Issue and Search Stock by Product ID.
- Output: Merged JSON.
- Notes: Ensures data continuity.
Create Record Issue (Supabase)
- Purpose: Inserts issue request into Supabase Materials Issued table.
- Input: Verified JSON.
- Output: New Supabase record.
- Notes: Auto-maps data; requires user-configured credentials.
Search Stock by Product ID (Supabase)
- Purpose: Retrieves Current Stock records.
- Input: JSON with Product ID.
- Output: JSON array of records.
- Notes: Filters by Product ID.
Issues Table Update (Supabase, True/False Branch)
- Purpose: Updates Supabase Materials Issued table.
- Input: Approval action JSON.
- Output: Updated Supabase record.
- Notes: Matches by Submission ID.
Update Current Stock (Supabase, True Branch)
- Purpose: Updates Supabase Current Stock table.
- Input: Updated stock JSON.
- Output: Updated Supabase record.
- Notes: Matches by Product ID.
Combine Issue Lookup Branches
- Purpose: Combines issue lookup branches.
- Input: Outputs from Retrieve Issue Request Details and Search Issue by Submission ID.
- Output: Merged JSON.
- Notes: Ensures data continuity.
Search Issue by Submission ID (Supabase)
- Purpose: Retrieves issue records by Submission ID.
- Input: Validated JSON.
- Output: JSON array of records.
- Notes: Filters by Submission ID.

Impact: Streamlines material issuance, ensures accurate stock updates, and provides proactive low stock alerts.

Conclusion

This automation enhances inventory management by integrating n8n with Google Sheets, Supabase, and Gmail. It reduces manual effort, ensures data accuracy, and keeps teams informed with timely alerts. Community feedback and contributions are welcome!

Material Issue Request and Approval

Purpose and structure

This folder contains the Material Issue Request and Approval workflow. Its executable nodes use code, gmail, googleSheets, if, itemLists, merge, set, supabase, webhook. The table and connection map below are derived from the JSON, not an inferred guarantee of behavior.

Setup

Import inactive. Configure your own credentials and replace REPLACE_WITH_* values. Review external destinations and Code nodes before running.

Entry points

Get Approvals, Receive Issue Request, Receive Raw Materials Webhook

Verification

Sanitized source candidate; not runtime-tested. This overview is generated from node metadata. Read the folder README for the connection map, credential types, and license.

Attribution

https://github.com/Zie619/n8n-workflows/blob/94007c1445d9258a7da116646b79473e7c7c3282/workflows/Code/0926_Code_Webhook_Create_Webhook.json MIT; preserve source notices.

Canvas section labels

These name areas of the original canvas; they do not include explanatory instructions.

Material Issue Request and Approval
Raw Materials Receiving and Stock Update

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