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Decagon vs Sierra
Both are enterprise AI support agents, priced by quote. Decagon is built around written procedures your team owns, with testing and QA built in; Sierra leans on meeting customers in messaging apps like WhatsApp and iMessage.
At a glance
| Fact | Decagon | Sierra |
|---|---|---|
| Made by | Decagon | Sierra |
| What it is | AI customer support agents for enterprises. | AI agents that give companies better customer experiences. |
| Price | Enterprise pricing | Enterprise pricing |
| Runs on | Not stated | WhatsApp, iMessage/SMS |
| Open source | No | No |
| Models | Not stated | Not stated |
| Last verified | October 14, 2026 | October 14, 2026 |
| Official site | decagon.ai | sierra.ai |
Where they differ
- Price: neither publishes prices; both quote enterprise contracts.
- Channels: Decagon covers voice, chat and email; Sierra lists WhatsApp and iMessage/SMS.
- Building the agent: Decagon uses Agent Operating Procedures (AOPs) with simulations, live A/B tests and always-on QA; Sierra offers Agent Studio and its Ghostwriter agent builder.
Which to pick
Choose Decagon if you want support procedures written in plain language that your team owns, and to test them with simulations and A/B tests before and after launch.
Choose Sierra if you want an agent that meets customers in messaging apps like WhatsApp and iMessage, built with Sierra's Agent Studio.
Keep looking
Facts from each maker's official pages, last verified October 14, 2026.