Fin vs Sierra vs Decagon: AI agents for customer service
Intercom’s Fin, Sierra and Decagon compared on deployment, how agents are configured, channels and pricing models for support teams.
AI customer service has moved beyond scripted chatbots to agents that resolve conversations, take actions in other systems and hand over to people with context. Fin by Intercom, Sierra and Decagon are three of the best-known options. They target different buyers: Fin can plug into almost any helpdesk, while Sierra and Decagon are built for large enterprises with complex customer journeys.
The short answer
- Choose Fin if you want an AI agent that works with your existing helpdesk, including Salesforce or HubSpot, or with Intercom’s own.
- Choose Sierra if you are a large brand that wants one agent across voice, chat, messaging and even ChatGPT, priced on outcomes.
- Choose Decagon if your support team wants to define agent behaviour in plain language and iterate without engineering sprints.
Side by side
| Fin by Intercom | Sierra | Decagon | |
|---|---|---|---|
| Best fit | Teams keeping their current helpdesk | Large enterprises | Large enterprises |
| Configuration | Knowledge, workflows and Intercom tooling | Ghostwriter builds agents from SOPs, transcripts, images or recordings | Agent Operating Procedures written in natural language |
| Channels | Chat, email, tickets, WhatsApp, SMS and more | Voice, chat, email, SMS, WhatsApp and ChatGPT | Chat, voice and email in one intelligence layer |
| Improvement tools | Performance analysis and quality monitoring | Testing, conversation research and proactive alerts | Testing, observability, experimentation and analytics |
| Pricing | AI usage plus optional Intercom helpdesk seats | Outcome-based, through sales | Through sales; no public price list |
Fin: the flexible option
Fin’s main advantage is that it does not force a platform change. It can sit on top of Salesforce, HubSpot and other helpdesks, transferring conversations to human agents in the inbox they already use, or it can be combined with Intercom’s full helpdesk. Intercom reports high average resolution rates across many customers; treat that as the vendor’s figure, since resolution depends heavily on the quality of your help content.
Sierra: one agent everywhere, paid on results
Sierra emphasises building production-ready agents quickly, even from messy inputs such as whiteboard photos or call recordings, and deploying the same agent across every channel. Its outcome-based pricing aligns cost with results, but you need clear agreement on what counts as a successful outcome before signing.
Decagon: procedures in plain language
Decagon replaces configuration languages with Agent Operating Procedures that support teams can read and edit. Combined with testing and experimentation tools, this is designed to let operations teams change policies, such as a returns rule, and validate the new behaviour quickly.
How to decide
- Measure your current volume by channel and the share of contacts that follow a clear procedure.
- Audit your knowledge base: AI agents are only as good as the content and policies behind them.
- Shortlist based on whether you need to keep your helpdesk or are open to replacing it.
- Ask each vendor how pricing is calculated for your volume and what counts as a resolution or outcome.
- Pilot on one well-defined contact type and compare resolution and customer satisfaction against humans.
Fin by IntercomAutomation
SierraAutomation
DecagonAutomation
BotpressAutomation
VoiceflowAutomation
Salesforce AgentforceBusinessTools to explore
Sources
Official vendor pages consulted for this analysis in October 2026. Plans, limits and features change: check the vendor’s page before you buy.
- Fin by Intercom: official site fin.ai
- Fin by Intercom: pricing fin.ai
- Sierra: official site sierra.ai
- Decagon: official site decagon.ai