Retell AI Custom Function Calling: Live CRM Lookups & Data Ingestion
How to equip Retell AI voice agents with real-time API tools to query active Clio matters, check attorney calendar availability, and push structured consultation summaries in under 2 seconds.
Beyond Standard Voice Prompts: The Power of Function Calling
A conversational voice AI agent is only as smart as the live data it can access. When an existing client or hot intake lead calls your law firm, an agent that merely takes a message provides a frustrating experience.
By configuring Retell AI custom functions, your agent can make asynchronous HTTP calls to your middleware during the call. For example, when a caller provides their phone number or case ID, the agent calls checkCaseStatus(callerPhone) and replies with their active attorney’s name and next court date.
Three Essential Retell AI Functions for Law Practices
1. lookupContactByPhone(phone)
Queries Clio Manage or GoHighLevel by E.164 phone number. Returns existing client name, assigned paralegal, and matter status.
2. bookConsultationSlot(datetime, email)
Directly interfaces with your Calendly or GHL Calendar API to book and confirm an appointment slot while the caller is still on the line.
3. saveIntakeDetails(structuredJson)
Extracts accident date, injuries, and opposing party information from the conversation and writes it to custom fields in Clio.
Post-Call Webhook Ingestion Pipeline
When the call terminates, Retell AI emits a call_analyzed webhook payload containing the full stereo audio URL, timestamped transcription, and LLM sentiment summary.
Our custom Retell AI CRM integration middleware ingests this webhook, extracts structured tags, attaches the call transcript to the Clio matter notes, and advances the pipeline stage in GoHighLevel to “Intake Consultation Completed”.