MorphScreen

MorphScreen is an open-source alternative to OpenUI and CopilotKit. It lets an AI model answer with real UI instead of a wall of text. The model writes Markdown with a few tags, so a short prompt teaches it (2,954 tokens with all 75 components). The core reads each line as it streams and checks it against the components the app allows; the API asks the same model to rewrite only the lines that break a rule; and the web SDK draws the answer as it arrives.The format, the Rust core and the SDKs are open source under Apache-2.0; the hosted API is the paid part. It works with any model on OpenRouter on your own key. Free plan with 3,000 calls a month and no card; Build is $49 a month, Scale $499.On OpenUI's own public benchmark, against the open-source OpenUI library: ahead on 37 of 64 measures, behind on 4, even on 23; 0 vs 599 accessibility violations across 20 answers. Method and raw answers: morphscreen.com/benchmark.