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Mostafa Mahmoud

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Purchase orders approved over WhatsApp

A construction finishing company's purchase and supply-order cycle, from request to approval to supplier, run entirely through WhatsApp and recorded in a database.

Role
Solution designer and builder; ran the client demo.
Period
2026
Status
Demo approved, production scoping
Stack
n8n, WhatsApp (Evolution API), Supabase

Architecture

System steps in order

  1. Request
    1. Site request on WhatsApp (Input)
    2. Record request (Data)
    3. Route by amount threshold (Logic). Feeds: Approver notified on WhatsApp
  2. Approval
    1. Approver notified on WhatsApp (Output)
    2. Approve or reject by reply (Input)
    3. Update status (Data). Feeds: Supplier step
  3. Supply
    1. Supplier step (Logic)
    2. Reminders on WhatsApp (Output)
    3. Full history per project (Data)

The problem

Staff on site requested materials by phone and chat. Approvals depended on who answered, and nothing was recorded, so spend per project could not be traced.

What I built

A WhatsApp-only workflow: a request is captured and recorded, routed for approval based on its amount, approved or rejected by reply, passed to the supplier step, and followed by reminders. Every step is stored in Supabase.

Key decisions

  1. Rules first, AI only where it pays. Running cost stays near zero and the flow is predictable.
  2. Reply-based steps. Interactive buttons are planned for the move to the official WhatsApp Cloud API.
  3. A real database from day one instead of spreadsheets, so it can grow into an ERP module.

Results

The demo ran without failures and the client moved to a requirements phase for a production ERP module (budget tracking per item and accounting integration).

In action

Project A supplies

  1. Site engineer

    Need 40 bags of tile adhesive for Villa 12, Project A

    09:15
  2. Procurement assistant

    Request PR-0193 recorded and sent to the site manager for approval (EGP 18,000).

  3. Site manager

    Approved

  4. Procurement assistant

    Sent to supplier. Reminder set for delivery date.

Behind the scenes

Recording request

item
Tile adhesive
qty
40
unit
bag
project
Project A
est_cost_egp
18000
route
Site manager approval
Demo data. The real systems run for companies in Egypt.

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