Claude 4.5 built Slack in thirty straight hours – here is my honest take after testing it thoroughly

Claude 4.5 rebuilt Slack in thirty straight hours. No stops, no 11,000 lines of code, and it worked. That's the headline out of Anthropic. They are pushing harder and harder into longer term tasks for agents. Why care? Why would we have Slack? We already have Slack. We care because this is what the future looks like. It looks like agents taking tasks and working for a long time, you know how chat GPT coming and just answer right away? Not anymore. We start to see and do work and come back after a while. We already see this in other areas. So chat GPT, their new Pulse product this week. Pulse is a great response delivered the next day. And so it looks at previous chats you've had and it proactively goes and thinks about things you might wanna think about and learn about and consume in a briefing every morning. It's only available to pro users right now, but like most of these things, it's coming to everybody soon. And the point is that proactive agents are going with us everywhere.