Platform
Retell AI agents built for conversation quality
Retell tends to reach a natural-sounding agent faster than the alternatives on conversational work, which matters when the job is talking to customers rather than orchestrating systems.
Quick answer
What is Retell AI used for?
Retell AI is a platform for building conversational voice agents that handle inbound and outbound calls. It manages speech recognition, language model responses, speech synthesis and telephony, and supports function calling so agents can look up and write data during a conversation.
The problem
What this actually fixes
Existing voice agents sound stilted and callers disengage.
Interruptions are handled badly, so the agent talks over people.
The agent takes messages rather than completing the booking.
Calls are not logged anywhere your team can see them.
Conversation quality varies unpredictably between calls.
Scope
What's included
Every engagement is scoped to what you actually need. This is the full deliverable list.
Deliverable 01
Agent development
Conversation design, prompt construction and behavioural boundaries built around one defined job.
Deliverable 02
Natural conversation tuning
Interruption handling, pacing and turn-taking configured so the call feels like a conversation rather than a menu.
Deliverable 03
Function calling
Live lookups and writes during the call — availability checks, contact creation, appointment booking.
Deliverable 04
GoHighLevel integration
Outcomes, transcripts and recordings written to the contact record automatically.
Deliverable 05
Telephony setup
Inbound and outbound numbers, routing, warm transfer and failover paths.
Deliverable 06
Review and tuning
Transcripts reviewed after launch and behaviour adjusted, because real calls always surface gaps.
How it works
From first call to running system
- Step
Scope the job
What the agent handles and where it must hand off.
- Step
Build and connect
Agent constructed, functions wired to your CRM and calendar, telephony provisioned.
- Step
Test realistically
Accents, noise, interruptions and out-of-scope questions, not a clean script.
- Step
Pilot then widen
Limited traffic first, reviewed, then expanded once transcripts justify it.
Conversation design carries the result
Whichever platform you choose, the agent’s quality comes mostly from how the conversation was designed rather than from the underlying technology.
An agent that asks sensible questions in a sensible order, recognises when it is out of depth and hands off gracefully will outperform a technically superior one that has been told to “handle enquiries” and left to improvise.
That is why our scoping spends more time on what the agent should refuse to do than on which platform runs it. The boundaries are the product.
Stack
What this connects to
- Retell AIConversational voice agents for inbound answering and outbound calling.
- TwilioPhone numbers, SMS delivery and call routing infrastructure.
- GoHighLevelCRM, pipelines, funnels, calendars and workflows — the system of record.
- OpenAILanguage models for qualification, summarisation and reply drafting.
Questions
Retell AI Integration — common questions
Retell or Vapi — which should we use?
Retell often reaches a good conversational result faster on straightforward agents. Vapi offers more configurability where telephony or function calling is complex. For most qualification and booking agents either works, and the conversation design matters considerably more than the platform choice.
Can a Retell agent book into our calendar?
Yes. Function calling lets it check live availability and write the booking during the conversation, so the appointment is confirmed before the caller hangs up rather than processed afterwards.
How natural does it sound?
Good enough that many callers do not raise it, though it is not indistinguishable from a person and we would not claim otherwise. Turn-taking and interruption handling affect perceived quality more than voice selection does.
What does it cost?
Usage-based, billed per minute across the platform, telephony and language model, separate from the build cost. We model expected monthly spend against your real call volume during scoping so it is not a surprise.
Does it work for outbound as well as inbound?
Yes. Outbound brings consent, calling-window and suppression obligations that inbound does not, and those are built into the calling logic rather than left as an operational process someone has to remember.
Related services
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Vapi voice agents wired into your CRM
Vapi is a platform for building programmable AI voice agents. It handles speech recognition, language model orchestration, speech synthesis and telephony, and exposes function calling so an agent can read and write external systems — checking calendars, creating CRM records or booking appointments during the call.
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