Five9 has one of the largest installed bases on Salesforce Open CTI, and it has now been clear about where those customers should go. Its answer is Five9 Fusion for Salesforce, and the company is pitching it as an end-to-end migration path rather than a quick package swap.
Key facts at a glance
- Open CTI has been in maintenance mode since 2020, with no new features.
- New Agentforce Service orgs cannot implement Open CTI (effective February 16, 2026).
- Open CTI retires with the Spring ’28 release; legacy connectors stop working on February 28, 2028.
- Salesforce recommends moving to Salesforce Voice, through a partner contact center or Agentforce Contact Center.
Here is what Five9 has said, what Fusion includes, and what Five9 customers should check before they plan a move.
The scale of the change for Five9 customers
In a September 3, 2026 Five9 blog post, Five9 says Open CTI is the framework behind its classic Five9 adapter, which more than 1,000 joint customers rely on today. The same post describes the Five9 and Salesforce relationship as more than 15 years old, with over 160,000 agents using the two platforms every day.
That classic adapter runs on Open CTI, so it falls under the same deadline as every other Open CTI connector. Salesforce’s retirement notice says that on February 28, 2028, legacy connectors will no longer function.
What Five9 Fusion for Salesforce includes
Five9 describes Fusion as a deep, native integration so agents work from one console instead of switching between a contact center app and the CRM. The features it highlights are:
- Voice inside the record. Recordings and call metadata land in Salesforce automatically, so call history sits next to everything else on the account.
- A choice of AI. Customers can run Five9 AI Agent Assist, with support for third-party AI such as Google, or use Salesforce Einstein for Service fed by live voice data streamed through Five9 TranscriptStream.
- Intelligent voice routing that reads the live interaction to pick the best available agent.
- Contextual handoffs. When a Five9 Voice AI Agent finishes a self-service interaction, its summary passes into the Salesforce voice call object, so customers do not repeat themselves.
Five9 also lists Bring Your Own Channel (BYOC) on the Fusion roadmap, which would extend the approach to digital channels.
The AI layer underneath
A follow-up Five9 post on September 10, 2026 goes deeper on the AI. It says AI Agent Assist provides real-time transcription, live guidance and automated call summaries, and confirms it is one of the two AI paths inside Fusion, the other being Einstein for Service. The post also describes Five9’s Voice AI Agents, including multi-agent orchestration, tool calling and warm handoffs to human agents.
For contact centers, the practical point is flexibility. You can standardize on Salesforce’s Agentforce and Omni-Channel workspace, or keep Five9’s own AI, workforce engagement and routing running as they do today.
What customers are asking
On the Five9 Community forum, one customer shared why they had not moved to Fusion yet: at the time of posting, it did not support web chat, and Salesforce Voice requires additional Salesforce user licensing. That is one customer’s experience, not an official Five9 statement, but it reflects two questions every Five9 customer should put to their account team: which channels Fusion supports today, and what the Salesforce-side license will cost.
What this means for your contact center
- Confirm which adapter you run. If agents use the classic Five9 adapter softphone, you are on Open CTI and have a hard deadline.
- Map channel coverage. Check which of your current channels Fusion covers now and which depend on roadmap items such as BYOC.
- Pick your AI path early. Five9 AI Agent Assist and Einstein for Service lead to different setup, licensing and reporting work.
- Budget for Salesforce licensing as a separate line item from Five9.
Even if you stay with Five9, this is a good moment to benchmark alternatives, since the Salesforce-side rebuild happens either way. If you want a comparison point, see how Vonage Contact Center for Salesforce approaches the same move.
Planning your Open CTI migration?
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