Are you rebuilding the Slack or Teams layer every time they ship an AI agent?

I’m trying to figure out if this is just something we keep running into, or if other people building agents are dealing with it too. The agent side feels like it’s getting better. Tools like LangGraph, CrewAI, OpenAI Agents and others make the actual logic easier to build than before. But the annoying part for us is still getting the agent into Slack or Microsoft Teams in a way that feels natural for the team using it. Every time we start a new project, we end up rebuilding a lot of the same stuff. Thread context, DMs versus channels, streaming responses, user permissions, OAuth, approvals before the agent takes actions, logs for debugging, and all the small things that make the agent actually usable inside a team chat. It feels like the hard part is not always the agent anymore. A lot of the work is in the layer where the agent actually talks to people. For anyone here building agents for real teams, have you had to build this layer yourself? Was the Slack or Teams integration more painful than expected? What part wasted the most time? Thread context, auth, streaming, permissions, deployment, or something else?