Builder.io open-sources agent-native, a cross-protocol UI layer

Builder.io has open-sourced agent-native, a framework that defines each UI capability once. That definition works over MCP, A2A, HTTP, and CLI at the same time. The function an AI agent calls as a tool is the same one the UI calls from code.

That removes a class of bugs where the UI can do something the agent can't, or the reverse.

The repo has 4,975 stars and 75 open issues since it went public on March 12. It's also on continuous build rather than semantic versioning. GitHub's release history shows v0.1.381-0 tagged at 03:04 UTC on September 19, an hour after v0.1.380-0 at 02:04 UTC. The cadence reads like an internal tool being tested in the open.

There's no license file on the repo record. For a Builder.io project that's probably an oversight, not a deliberate all-rights-reserved stance. It still means the code isn't clear to vendor into a product yet.