What is Sierra?
Sierra is a conversational AI platform for businesses that want to deliver customer experiences through AI agents. Companies use it to build agents that handle customer interactions across chat, SMS, WhatsApp, email, voice and ChatGPT from a single agent. The platform includes Ghostwriter, an agent-building tool that creates a production-ready, multilingual agent from uploaded SOPs, transcripts, whiteboard photos or audio recordings, or from a plain-English description of the goal.
After deployment, Sierra offers tools to monitor and improve agents. Insights features include Explorer for ChatGPT-style analysis of conversations, Monitors that flag conversations needing attention, Experiments for multivariate testing, and Observability into tool calls, knowledge lookups and latency. Horizon adds long-horizon planning, customer memory across touchpoints, outcome optimization and proactive engagement triggered by real-world signals. Pricing is described as outcome-based, so customers pay for the value delivered.
Key features
- Ghostwriter builds agents from SOPs, transcripts, photos or audio or plain-English goals
- Single agent deployed across chat, SMS, WhatsApp, email, voice and ChatGPT
- Insights Explorer for conversation analysis and Monitors for flagged conversations
- Experiments for multivariate testing of agent performance
- Horizon for long-horizon planning, customer memory and proactive engagement
- Observability of tool calls, knowledge lookups and latency
Who is it for
- Large companies with customer service operations
- Financial services, healthcare, telecom and retail businesses
- Product and operations teams building agents without engineering support
Pros and cons
- Single agent works across many channels
- Built-in tools to monitor and improve agent performance
- Outcome-based pricing ties cost to delivered value
- Pricing is not publicly listed on the homepage
- Aimed at businesses, not individual users
Sierra pricing
The vendor does not publish prices in a readable form (often pricing is shown only after signing in).
Is Sierra free?
The vendor does not state this clearly on the homepage or pricing page.
Sierra alternatives
| Tool | Price from | Free plan | Category |
|---|---|---|---|
 Crisp | 45 USD/mo | trial | Customer support & chatbots |
 Retell AI | 0.07-0.31 USD/mo | trial | Customer support & chatbots |
 Voiceflow | not listed | trial | Customer support & chatbots |
 Tidio | 29 USD/mo | yes | Customer support & chatbots |
 Zendesk AI | 19 USD/mo | trial | Customer support & chatbots |
 AgentDock | 39 USD/mo | yes | Customer support & chatbots |
FAQ
What is Sierra used for?
Conversational AI platform that lets businesses build and run customer service and sales AI agents across chat, voice, SMS, email and more.
Is Sierra free?
The vendor does not state this clearly on the homepage or pricing page.
How much does Sierra cost?
The vendor does not publish prices publicly or requires sign-in.
What are the best Sierra alternatives?
Closest alternatives: Crisp, Retell AI, Voiceflow, Tidio, Zendesk AI.
Data checked October 12, 2026 on the vendor website (sierra.ai).