The call and the email are one case.
HEIDI handles customer-facing inbound voice and connects the call to the operational mailbox, reviewed knowledge, and playbooks. A reply or sensitive next step stays awaiting human approval before it is sent or executed.
- Customer-facing inbound voice plus a connected operational mailbox
- One case across the phone call and its email thread
- Reviewed Operational Knowledge and playbooks guide the next step
No credit card required. Switch to a paid plan any time.
HEIDI, Parloa, and fonio all cover customer-facing voice. Choose HEIDI when the same request also lives in email and must stay grounded and approval-gated. Choose Parloa for enterprise contact-center agent management on telephony and CCaaS. Choose fonio for a focused AI phone assistant for inbound calls and appointments. Consumer voice and suite copilots overlap on conversation, not on this operating layer.
Best for HEIDI
- Inbound voice connected to the mailbox
- Playbook-grounded next steps
- Approval before a sensitive send
- Operator guidance when work moves into an app
Best for AI voice agents
- Dedicated contact-center and phone-assistant stacks such as Parloa and fonio
- Consumer conversational voice
- Suite-native personal assistance
Overview
Top options at a glance
A quick overview to help you shortlist. Then pick the tool that matches your team's needs.
HEIDI Voice
RecommendedBest for
Customer-facing inbound voice that continues in the operational mailbox
Standout
Call + email as one case
Notes
Connects call context, reviewed Operational Knowledge, playbooks, and an approval-gated next step.
Parloa
Best for
Enterprise contact-center AI agent management
Notes
Customer-facing voice and contact-center containment; assess mailbox continuity and governance for your operating model.
fonio
Best for
Focused AI phone assistance for inbound calls and appointments
Notes
Customer-facing phone handling, routing, appointments, and CRM-connected workflows; assess operational mailbox continuity separately.
ChatGPT Voice / Gemini Live
Best for
General consumer conversation and Q&A
Notes
Conversational interfaces, not a shared operational case across phone and email.
Microsoft Copilot
Best for
Suite-native personal assistance
Notes
Microsoft 365 assistance with voice-adjacent experiences; not this phone-and-mailbox operating layer.
Voice-agent platforms
Best for
Building phone-agent runtimes
Standout
Vapi · Retell · ElevenLabs Agents
Notes
Vapi, Retell, and ElevenLabs Agents are developer and platform examples; teams supply the operating model and governance.
Deep comparison
Feature-by-feature analysis
A nuanced look at how each platform handles key capabilities.
Inbound customer voice
HEIDI
StrongHEIDI can handle customer-facing inbound voice and continue the request in the governed operating layer.
AI voice agents
StrongParloa and fonio are strong customer-facing phone and contact-center examples.
The question is not whether the call can be answered, but where the case continues.
Mailbox continuity
HEIDI
StrongCall context and the operational mailbox can remain one case, grounded in reviewed knowledge and playbooks.
AI voice agents
NeutralPhone-agent stacks focus on telephony; connected mailbox continuity is a separate operating-model decision.
Contact-center telephony stack
HEIDI
NeutralHEIDI is not presented as a CCaaS-native SIP or Genesys replacement.
AI voice agents
StrongParloa is suited to enterprise contact-center agent management and telephony programs.
Quick comparison
Feature comparison table
High-level summary
| Feature | HEIDI | AI voice agents |
|---|---|---|
| Customer-facing inbound voice | Strong | Strong for Parloa and fonio |
| Connected operational mailbox | Strong | Neutral — separate stack |
| Same case across phone and email | Strong | Neutral — phone-first continuity |
| Reviewed Operational Knowledge / playbooks | Strong | Varies by implementation |
| Approval before sensitive send or action | Strong | Varies by workflow |
| UI highlighting / shared app map | Available as additional operator guidance | Neutral — different stack |
| Consumer general Q&A | Operational focus | Strong for consumer voice |
| CCaaS-native telephony | Neutral — not a SIP or Genesys replacement | Strong for Parloa contact-center programs |
Decision guide
Which tool is right for you?
Answer these questions to find your best fit.
Does the customer also email the same request?
If yes → HEIDI
Choose a connected case model that keeps the call and mailbox together.
If no → AI voice agents
A focused phone-assistant stack may fit.
Does the next step have to stay approval-gated after the call?
If yes → HEIDI
Use HEIDI to prepare the governed next step for human approval.
If no → AI voice agents
Compare phone-agent workflows by the controls your program requires.
Is this a dedicated contact-center telephony program?
If yes → HEIDI
Evaluate Parloa and your CCaaS requirements.
If no → AI voice agents
Prioritise mailbox continuity, knowledge, and the case workflow.
Frequently asked questions
Learn more about how HEIDI works and how it can help your organization.
Is HEIDI affiliated with Parloa, fonio, or the other named products?+
No. HEIDI, Process Designer, and UpQuAI Solutions AG are independent. Named third-party products are used for identification and comparison only, are trademarks of their owners, and do not imply affiliation or endorsement. This comparison reflects our understanding of generally available capabilities.
Does HEIDI handle customer-facing voice?+
Yes. Call HEIDI at +41 44 505 50 03 for customer-facing inbound voice. The call includes AI disclosure and can continue as a governed case with the connected mailbox.
Does HEIDI replace Parloa or fonio?+
There is overlap on inbound voice. HEIDI differs by connecting the mailbox, reviewed knowledge, playbooks, and an approval-gated next step as one case.
Does HEIDI auto-send an email from a call?+
No. A prepared reply or sensitive next step remains awaiting human approval before it is sent or executed.
Where should I start?+
Explore /heidi, /heidi-voice-assistant, or contact us at /contact to discuss your call-and-mailbox workflow.