ACP draws a clear line between what MCP does (connecting agents to external tools and data) and what the IDE-agent handshake needs to be: structured, bidirectional, and editor-aware. The protocol covers how an agent requests file context, how it surfaces diffs back into the editor, and how IDEs signal user intent without bespoke integrations per tool. The announcement at KotlinConf positions JetBrains squarely at the center of agentic coding infrastructure rather than as a passive host for third-party plugins. Whether the wider IDE ecosystem rallies around ACP or forks it into competing flavors is the open question — but having a vendor with JetBrains' install base driving the spec is a reasonable starting point.