n8n Workflow: Qualify Twilio & Retell Replies + Book Google Calendar

Automatically qualify Twilio SMS + Retell replies, book Google Calendar interviews, and log everything

This n8n workflow receives inbound Twilio SMS replies, Twilio delivery callbacks, and Retell call analysis webhooks—then verifies signatures, qualifies candidates with rule-based criteria, and books interview slots in Google Calendar. It also updates your recruiting systems by writing notes, notifying teams, and logging events in Supabase.

What this workflow does

• Receives webhooks from Twilio (inbound SMS or status callback) or Retell (call_analyzed) and loads runtime configuration.
• Verifies webhook signatures for Twilio or Retell, rejecting untrusted requests (unless running in preview mode).
• Normalizes inbound data into a single event format, detects SMS intent (opt-out, interested, not interested, question, unclear), and ignores non-actionable updates (e.g., delivery receipts or non-final Retell events).
• Handles opt-outs by calling a Supabase RPC to stop all outreach for the phone number (and optionally prepares a one-time confirmation message).
• Qualifies candidates using configured QUALIFY rules, including structured answers from Retell when present—assigning qualified / not qualified / needs review / no answer outcomes.
• Books interviews for qualified candidates by selecting the job recruiter and creating a Google Calendar event when calendar booking is enabled and the workflow is running in live mode.
• Queues writes and notes back to an ATS, notifies recruiters via Slack and Gmail, and logs the inbound event to Supabase.

Use cases

• Turn Twilio SMS replies into a qualified/no-qualified decision and schedule interviews instantly.
• Use Retell call analysis to validate candidate responses and reduce manual screening.
• Ensure compliant communications by processing SMS opt-outs and recording events centrally.

Technical details

• n8n nodes/tools: if, code, webhook, merge, gmail, sticky note
• Integrations: Twilio webhooks, Retell call_analyzed webhooks, Google Calendar booking, Slack notifications, Gmail notifications, ATS note/queue writes, and Supabase event logging + Supabase RPC for opt-outs.