Estera vs Gstack Meeting Agents: Features, Pricing & Which Is Better (2026)
A side-by-side comparison of Estera and Gstack Meeting Agents — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.
Estera
Estera
An AI receptionist that answers phone calls and WhatsApp messages 24/7, qualifies leads, and books appointments in 50+ languages.
Key features
- Inbound Voice Agent: Answers phone calls in under five seconds and handles reservations, questions, and busy-hour overflow.
- WhatsApp Concierge: Replies to WhatsApp messages 24/7 using the business's own WhatsApp Business number.
- Outbound Messages: Runs outbound WhatsApp campaigns for reminders, follow-ups, and re-engagement.
- Calendar & CRM Booking: Writes appointments directly into the business's existing calendar, PMS, or CRM.
- Business-specific Training: Trained on the business's services, prices, policies, and FAQs for on-brand responses.
- 50+ Languages: Speaks and replies in over fifty languages so international customers get help in their own language.
- Fast Setup: Creates a working AI agent assistant in under three minutes with no engineering required.
- Number Preservation: Uses your existing phone and WhatsApp Business numbers instead of forcing a switch.
Best for
- Restaurant Reservations: Handle bookings, special requests, and busy-hour calls without staff on the phone.
- Hotel Front Desk: Answer availability, amenities, and booking questions in guests' languages around the clock.
- Dental & Medical Clinics: Book appointments and handle intake questions on WhatsApp and voice.
- Real Estate Lead Qualification: Screen inbound inquiries about listings and route qualified leads to agents.
- SMB Overflow Coverage: Catch after-hours and busy-hour calls that would otherwise go to voicemail.
Gstack Meeting Agents
AgentCall
Open-source voice agents — CEO, YC partner, QA lead and more — that join your Google Meet, critique your screen, and drop notes in chat.
Key features
- Specialist Personas: Multiple pre-built AI specialists (CEO, CSO, QA lead, YC partner, designer, and more) join meetings in-persona.
- Google Meet Integration: Agents join real Google Meet calls as 3D-avatar participants alongside humans.
- In-meeting Critique: Agents watch your shared screen and critique it out loud, taking turns like real participants.
- Structured Chat Notes: Each persona drops written notes and scores in the meeting chat so feedback is captured, not just spoken.
- Local Brain: Uses your own local coding-agent session (Claude Code, Cursor, Codex) so audio and files stay on your machine.
- MIT-licensed: The platform and personas are open source under MIT license.
- AgentCall Demo: Built on the AgentCall API that lets any agent take a seat in a meeting, so custom personas are possible.
Best for
- YC Interview Prep: Practice pitching to a YC-partner persona that opens with the questions real partners ask.
- Product & Design Review: Get a designer persona to score a UI or landing page in real time.
- Startup Feedback Sessions: Simulate an exec team (CEO, CSO, QA) reviewing a demo before you show real stakeholders.
- Async Meeting Notes: Use the specialist chat notes as structured meeting minutes without a human notetaker.
- Custom Agents in Meetings: Build your own persona on top of AgentCall to join calls with domain-specific expertise.