# Ghostwriter: When AI goes from tool to teammate > Source: > Published: 2026-09-28 15:00:00+00:00 # Ghostwriter: When AI goes from tool to teammate If you’ve tried [Instinct](https://instinct.com/) or [Muse](https://ai.meta.com/muse/), you may have had that moment: Wait, it noticed that? Your agent spots something you missed, figures out what to do, and comes back with a solution. Maybe it catches a change to your flight and finds a better option before you’ve even opened the airline app. The first time that happens it changes how you think about AI. This agent is not just a tool, *it’s got my back*. In the business world, we’ve been marching in this direction, but haven’t quite gotten all the way there. Agents are writing almost all code but they’re not yet tapping developers on the shoulder with feature ideas or an A/B test to run. With [Sierra’s Ghostwriter](https://sierra.ai/product/ghostwriter), our customers have transitioned from *code* to *clicks* to *prompts*, dramatically speeding up how they build and deploy agents. But Ghostwriter isn’t DMing you on Slack when it thinks your AI agent’s sales promotion’s lost its effectiveness. Until today. ## Eyes in the back of your head We’ve transformed Ghostwriter from a tool you prompt to a teammate in Slack and Teams that’s always on, proactive, asynchronous, and creative. Rather than signing into Sierra to use Ghostwriter as a copilot to an application, you add Ghostwriter to your channel, and Ghostwriter joins your team. From there, you can @-mention Ghostwriter for anything - for an update about how your customer service resolution rate is trending, or a chart of how your sales funnel is converting, or to kick off a new experiment. But the real magic happens when Ghostwriter starts coming to you with ideas. With the context of your team’s conversations and the millions of customer interactions your agent is having, this new version of Ghostwriter will help you find insights and business ideas you didn’t even know you needed. What started as “I did what you asked” has become “I think I found a better way to do it”, “I noticed something you should see” or “I have an idea we have not tried”. ## “I think I found a better way to do this” One of our customers wanted to resolve more calls without transferring their customers to a support associate. Every week, the team would meet to review calls, discuss ideas from different people and decide what to try next. It took about a week. Ghostwriter now does the first pass for them. It reviews recent calls, identifies three specific changes, shows the conversations behind each one, estimates how many customers each change could help and recommends which two to tackle first. It even shares a wall of love — five moments of customer delight as inspiration to improve the agent. It then helps turn those ideas into experiments, monitors the results and tells the team when they’re statistically significant. It isn’t just answering a question or completing a task. It knows the outcome the team wants and keeps moving them toward it. ## “I noticed something you should see” At another company, Ghostwriter investigated what looked like a payment failure. It discovered that the payment had actually succeeded, but the response from the company’s system was missing a policy number. It then proposed separate fixes for the backend system and the agent integration. ## “I have an idea we have not tried” Because it sees the conversations, releases, experiments and the discussion happening in Slack, Ghostwriter can make connections that would be difficult for any one person to see. Last week, for example, Ghostwriter reviewed conversations for one company and suggested an experiment that nobody had thought about. It had spotted an opportunity to increase both resolutions and revenue, found the conversations that supported its idea and proposed how the team could test it. Nothing was obviously broken. It just observed a pattern across conversations and came up with a new idea. ## Ghostwriter picks up on social cues With agents, personality matters. So we gave Ghostwriter one that is all about reading the room and understanding when to be helpful. That’s partly about understanding the team’s priorities. But knowing when to stay silent and when to chime in is key as well. It’s why we’ve designed Ghostwriter to have the judgment to keep quiet unless it has something meaningful to say and pick up on social cues, like nobody replying to its messages (that happens to us too). It also reflects weekly (very California) on how it showed up and adapts based on the direct and indirect feedback it received. Last month, one of our customers was assembling a list of papercuts, which it was discussing in Slack ahead of a Tuesday review. The afternoon before that review, Ghostwriter posted a list of examples it believed could be good additions to the papercut list, tagging in the appropriate person. It all happened organically because Ghostwriter was paying attention to what the team cared about. ## Ghostwriter — your trusted teammate In a world where everyone has access to the same intelligence, what differentiates your company? The context and relationships you’ve built with customers. It’s something that is uniquely yours and can create a compounding advantage over time. With Ghostwriter, it’s quick and easy to build agents so you can have more conversations, with more customers, in more meaningful ways. And then Ghostwriter helps you understand that context more deeply, create better experiences, and grow your business. So perhaps it’s more like 1,000 trusted teammates versus just one. But you can now judge for yourself as we’ll start rolling it out more broadly next week.