Manage Zendesk tickets and contacts via Placetel AI Voice Agent calls

Description

Quick overview
This webhook-based workflow lets a Placetel AI Voice Agent look up callers and manage Zendesk users and tickets by sending an operation in each request, returning a speech-ready response for the agent to read back.

How it works
Receives a POST webhook request from Placetel with an operation and caller context details.
Parses the request, extracts the requested operation, and normalizes the caller phone number to a German +49 format for consistent Zendesk matching.
Routes the request by operation to the corresponding Zendesk action (search or create a user, create or update tickets, list open tickets, or update a user).
For caller identification operations, searches Zendesk users by the normalized phone number and returns a speech response indicating whether a matching customer is found and/or verified.
For ticket operations, creates callback, call-log, or regular tickets in Zendesk, or fetches/updates an existing ticket for status, internal notes, or escalation.
Returns a JSON webhook response that includes a concise speech string and key IDs (such as customer_id or ticket_id) for the voice agent to continue the conversation.

Setup
Add a Zendesk OAuth2 credential in n8n and select it in each Zendesk node.
Activate the workflow and copy the webhook URL for the POST /placetel-zendesk endpoint.
In Placetel, configure your AI Voice Agent (custom tool) to POST to the webhook URL and to always send an operation plus phone from %%caller_number%%.
Ensure your Zendesk instance supports user search by phone and that your user phone numbers are stored consistently (the workflow normalizes to +49 / 49 formats).
Review and adjust the identity verification logic to match your Zendesk user fields and what you consider acceptable verify_value inputs before using it in production.