H
    Hestur
    Platform / Retell AI

    Expert Retell AI
    Development

    We build HIPAA-compliant voice AI agents on Retell — the platform built for regulated industries. Visual flow editor, sub-600ms latency, and a compliance architecture that passes audit.

    HIPAA BAA availableSub-600ms latencyVisual flow editor2–3 week deploy
    What We Build

    Retell Wins in
    Regulated Industries

    Insurance, healthcare, and financial services have compliance requirements that standard voice AI platforms cannot meet out of the box. Retell is built for this.

    Insurance Qualification & Claims Intake

    Inbound and outbound agents for policy qualification, first-notice-of-loss intake, and claims status updates. Retell's HIPAA/compliance-ready infrastructure and visual flow editor map directly to insurance call scripts — no translation layer needed.

    P&C, health insurance, life, brokerage

    60–75% IVR containment on routine inquiries

    Healthcare Scheduling & Triage

    HIPAA-compliant appointment booking, patient triage, referral coordination, and after-hours answering. Retell's encrypted data handling and BAA support make it the right choice for healthcare without custom infrastructure work.

    Medical practices, dental, mental health, home health

    Sub-600ms responses, BAA on Business plan

    Financial Services IVR Replacement

    Replace legacy IVR trees with conversational AI agents that understand intent rather than menu numbers. Account inquiries, loan status, payment processing confirmations, and appointment scheduling — all on Retell's compliant infrastructure.

    Banking, lending, mortgage, credit unions

    70–80% IVR deflection without compliance exposure

    Regulated Outbound Campaigns

    Outbound agents built for compliance — script adherence tracking, call recording for audit, do-not-call list integration, and consent management. Built specifically for industries where every call has legal exposure.

    Debt collection, financial services, regulated healthcare

    Full script adherence + audit trail on every call

    Platform Differentiator

    The Visual Flow Editor

    Retell uses a state machine model with a drag-and-drop editor. For regulated scripts with complex branching, this is the right abstraction — not a free-form LLM prompt.

    Prompt-first (Vapi) — flexible, less structured

    System prompt defines all logic in natural language.

    Great for: open-ended conversations,

    personalised interactions, simple flows.

    Risk: edge cases rely on LLM judgment.

    State machine (Retell) — explicit branching

    Node: Greeting

    → Branch: "claim" → Node: ClaimsIntake

    → Branch: "policy" → Node: PolicyLookup

    → Branch: "billing" → Node: BillingAgent

    → Fallback: Node: TransferHuman

    Every path is explicit. No LLM improvisation.

    When the visual editor wins

    Regulated script compliance

    Insurance, FDCPA debt collection, and financial services require exact script adherence. State machine nodes lock each path — no LLM deviation possible.

    Non-technical teams iterate on flows

    Compliance officers and operations managers can modify conversation flows without a developer. In regulated environments, this reduces the engineering bottleneck on every script update.

    Complex multi-branch logic

    When a call flow has 15+ decision points and each branch has different data requirements, a visual state machine is easier to audit and maintain than a 2,000-word system prompt.

    Audit and version control

    Every flow version is saved and restorable. For compliance audits, you can show exactly what script version was active on a given call date — not possible with prompt-based platforms.

    Compliance Architecture

    HIPAA Setup — 5 Steps

    A BAA alone does not make your Retell deployment HIPAA-compliant. These five steps complete the architecture.

    01

    Enable Business Associate Agreement

    Retell offers BAA on the Business plan. We initiate and execute this before any PHI touches the platform. This covers your Retell account; your STT/TTS providers need separate BAAs.

    02

    Separate BAAs for each BYOK provider

    Deepgram: BAA available on Enterprise plan. ElevenLabs: BAA on Business plan. OpenAI: BAA available on ChatGPT Enterprise (not standard API) — use Azure OpenAI instead for PHI in LLM context.

    03

    Minimise PHI in call context

    Design prompts to avoid holding PHI in the LLM context window. Patient identifiers (name, DOB, member ID) go to function calls that query your HIPAA-compliant backend — not into the system prompt or conversation history.

    04

    Configure data retention and recording

    Retell logs call transcripts by default. Set retention policy to minimum required (often 6 years for HIPAA). Disable recording for calls that do not require audit trail. Store recordings in your own S3 bucket with server-side encryption.

    05

    Audit logging and access controls

    Enable audit logging in Retell dashboard. Restrict dashboard access to minimum-necessary team members. Log every production config change. Review access quarterly.

    Platform Selection

    Retell vs Vapi vs LiveKit

    There is no universally right choice. Here is the signal-based decision matrix we use internally.

    SignalPickWhy
    Non-technical team needs to iterate on call flowsRetellVisual flow editor — no code required for flow changes
    HIPAA compliance required without custom infraRetellBAA available on Business plan, encrypted by default
    Complex conversation branching logicRetellState machine model maps naturally to regulated scripts
    API-first, full programmatic controlVapiDeeper webhook ecosystem, more LLM provider options
    Scale above 10k min/month, cost is primary driverLiveKitInfra cost collapses; managed platform fees compound
    Multi-agent handoffs or video roomsLiveKitOnly platform with first-class multi-agent architecture

    Retell BYOK cost: $0.07/min platform fee + $0.006/min Deepgram + $0.05–0.10/min LLM + $0.02–0.04/min TTS = $0.15–0.25/min all-in. Slightly cheaper than Vapi BYOK ($0.23–0.33/min) at low-to-medium volume. LiveKit beats both above 10k minutes/month.

    Sub-600ms
    response latency
    Retell platform target
    HIPAA
    BAA on Business plan
    compliant by design
    $0.15–0.25
    per minute BYOK
    lowest managed cost
    2–3 weeks
    to production
    including compliance review
    What We Solve

    5 Retell Pitfalls
    in Regulated Deployments

    01

    Problem

    Flow editor overconfidence

    Impact

    Teams use the visual editor to build flows without engineering review. Works fine in demo; collapses under edge cases (caller interruptions, ambiguous intent, multi-step data collection) that the visual model cannot express cleanly.

    Our Fix

    We treat the visual editor as the specification layer, then validate every flow branch with adversarial test calls. Edge cases get explicit fallback nodes — not implicit LLM judgment.

    02

    Problem

    PHI leaking into LLM context

    Impact

    Developers include patient name, DOB, or member ID in the system prompt for personalisation. This passes PHI to a non-HIPAA-covered API endpoint and creates a compliance violation on every call.

    Our Fix

    We architect a function-call boundary: the agent calls your HIPAA-compliant API to retrieve patient data mid-conversation, uses it only within that tool call response, and never stores it in LLM context.

    03

    Problem

    Script drift on outbound compliance calls

    Impact

    LLMs improvise when callers go off-script. In regulated industries — debt collection, lending, insurance — an improvised statement can create legal liability.

    Our Fix

    For compliance-critical paths, we implement constrained generation: the LLM selects from a pre-approved response set rather than generating freely. Off-script callers get a redirect, not an improvised answer.

    04

    Problem

    Retell 600ms latency ceiling

    Impact

    Retell targets 600ms response time. With heavy function calling (multiple API lookups per turn), response time can exceed 1s — noticeable on phone calls.

    Our Fix

    We profile every function call and parallelise where possible. For lookup-heavy flows, we pre-fetch likely data (patient record, account status) at call start and cache it for the duration of the call.

    05

    Problem

    Missing do-not-call and consent handling

    Impact

    Outbound campaigns without DNC integration and consent verification create TCPA exposure. A single complaint can exceed the cost of the entire campaign.

    Our Fix

    We build DNC list checks into the pre-dial validation function — calls do not go out if the number is on the list. Consent records are written to your CRM before the call is made and verified at call start.

    Timeline

    Compliance-First Build Process

    Week 1

    Compliance & Architecture

    • BAA execution with Retell and each BYOK provider
    • Call flow mapping and compliance requirements review
    • Function call spec for HIPAA-safe data retrieval
    • BYOK provider selection optimised for your audio profile
    Week 1–2

    Build & Integration

    • Visual flow build with all conversation branches
    • Function calling implementation — CRM, calendar, EHR
    • DNC/consent integration (outbound only)
    • Custom LLM prompt engineering for constrained generation
    Week 2–3

    Validation & Go-Live

    • Compliance review of all call recordings and transcripts
    • Adversarial testing: edge cases, interruptions, off-script callers
    • Latency profiling and function call optimisation
    • Production deployment with audit logging active
    Ready to Build?

    Ship a Compliant Retell Agent
    in 2–3 Weeks

    We scope and price every Retell project in a single 30-minute call — BAA execution, flow design, and compliance review included.