{"id":28055,"library":"prefab-ui","title":"Prefab","description":"Prefab is a generative UI framework for Python by PrefectHQ. It allows building interactive web UIs with pure Python, using reactive components. Current version: 0.19.1, requires Python >=3.10. Release cadence is active with frequent minor/patch releases.","status":"active","version":"0.19.1","language":"python","source_language":"en","source_url":"https://github.com/PrefectHQ/prefab","tags":["ui","generative","reactive","prefect","dashboard"],"install":[{"cmd":"pip install prefab-ui","lang":"bash","label":"Install from PyPI"}],"dependencies":[{"reason":"Prefab is built by PrefectHQ and often used alongside Prefect workflows, but not required.","package":"prefect","optional":true},{"reason":"Used for form models and data validation.","package":"pydantic","optional":false}],"imports":[{"wrong":"import prefab","symbol":"PrefabApp","correct":"from prefab_ui import PrefabApp"}],"quickstart":{"code":"import prefab\nfrom prefab import App, components\n\napp = App(\n    components.Button(text=\"Hello, World!\")\n)\n\nif __name__ == \"__main__\":\n    app.serve()","lang":"python","description":"Minimal app with a button, served locally."},"warnings":[{"fix":"Use `import prefab` or `from prefab import ...`","message":"Import as `prefab` not `prefab_ui` – the PyPI package name and import name differ.","severity":"gotcha","affected_versions":"all"},{"fix":"Use `from prefab.components import Button, Form, ...`","message":"Components must be imported from `prefab.components` submodule, not directly from `prefab`.","severity":"gotcha","affected_versions":">=0.16.0"},{"fix":"Use `prefab.state.State` or `prefab.state.Reactive` for mutable state.","message":"Reactive state management requires understanding `prefab.state` and reactive variables; misuse can cause silent UI failures.","severity":"gotcha","affected_versions":"all"},{"fix":"Upgrade to 0.19.1+ or implement prefill manually.","message":"The `Form.from_model` runtime prefill feature was added in v0.19.1; earlier versions do not support `defaults` kwarg.","severity":"gotcha","affected_versions":"<0.19.1"},{"fix":"Upgrade to 0.17.0+ or set `show_legend=True` explicitly.","message":"Charts default to `show_legend=True` only from v0.17.0+; earlier versions had no legend.","severity":"gotcha","affected_versions":"<0.17.0"}],"env_vars":null,"search_vec":"'0.19.1':26 '3.10':29 'activ':33 'allow':13 'build':14 'cadenc':31 'compon':23 'current':24 'dashboard':42 'framework':7 'frequent':35 'generat':5,39 'interact':15 'minor/patch':36 'prefab':1,2 'prefect':41 'prefecthq':11 'pure':19 'python':9,20,28 'reactiv':22,40 'releas':30,37 'requir':27 'ui':6,17,38 'use':21 'version':25 'web':16","created_at":"2026-05-09T05:53:30.078074+00:00","updated_at":"2026-05-09T05:53:30.078074+00:00","problems":null,"ecosystem":"pypi","meta_description":null,"install_score":null,"quickstart_score":null,"quickstart_tag":null,"pypi_latest":null,"cli_name":"","cli_version":null,"type":"library","homepage":"https://prefab.prefect.io","github":"https://github.com/PrefectHQ/prefab","docs":"https://prefab.prefect.io","changelog":null,"pypi":"https://pypi.org/project/prefab-ui/","npm":null,"openapi_spec":null,"status_page":null,"smithery":null,"categories":["web-framework"],"base_url":null,"auth_type":null,"provenance":{"verified_status":"passing","verified_at":"2026-07-03","last_verified":"2026-07-03","next_check":"2026-08-02","install_tag":null}}