{"passport":{"unfragile":{"@version":"1.0","version":"2026-05","artifact":{"id":"pypi_pypi-mesop","slug":"pypi-mesop","name":"mesop","type":"framework","url":"https://github.com/mesop-dev/mesop","page_url":"https://unfragile.ai/pypi-mesop","categories":["app-builders"],"tags":["mesop"],"pricing":{"model":"open_source","free":true,"starting_price":null},"status":"active","verified":false},"capabilities":[{"id":"pypi_pypi-mesop__cap_0","uri":"capability://code.generation.editing.python.to.ui.declarative.component.definition.with.decorators","name":"python-to-ui declarative component definition with decorators","description":"Mesop uses Python decorators (@component, @content_component, @web_component) to define UI components as pure Python functions, eliminating the need for HTML/CSS/JavaScript. The framework translates decorated Python functions into a component tree that gets serialized to protobuf (ui.proto) and sent to the browser for rendering. 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The type information is also used to generate the protobuf schema for client-server communication.","intents":["Get IDE autocomplete for component props","Catch prop type errors at development time","Document component APIs via type hints","Validate props at runtime"],"best_for":["Teams using type-checked Python (mypy, pyright)","Large codebases with many components","Developers wanting IDE support for component APIs"],"limitations":["Type hints are optional — developers can ignore them","Runtime type validation adds overhead","Complex types (unions, generics) may not serialize to protobuf correctly","Type checking requires separate mypy/pyright setup"],"requires":["Python 3.9+ (for type hints)","Type hints on component functions","Optional: mypy or pyright for static type checking"],"input_types":["Component function definitions with type hints","Props passed to components"],"output_types":["Type-checked component tree","IDE autocomplete suggestions"],"categories":["code-generation-editing","ui-framework"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"pypi_pypi-mesop__cap_2","uri":"capability://memory.knowledge.session.scoped.state.management.with.stateclass.dataclasses","name":"session-scoped state management with @stateclass dataclasses","description":"Mesop uses Python dataclasses decorated with @stateclass to define application state that persists across events within a user session. 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This is implemented via file watchers and Flask's development server, allowing developers to see changes instantly without manual browser refresh.","intents":["Iterate rapidly on UI components without restarting the server","See changes reflected in the browser immediately after saving code","Maintain session state while developing (e.g., form data persists across reloads)","Debug UI issues without losing application context"],"best_for":["Development and prototyping workflows","Rapid iteration on UI components","Teams using local development servers"],"limitations":["Hot reloading only works in development mode — not available in production","Complex state mutations may not reload cleanly if component signatures change","File watching adds overhead — can be slow on large codebases with many files","Requires Flask development server — not compatible with production WSGI servers"],"requires":["Python 3.9+","Flask development server","File system watchers (watchdog or similar)"],"input_types":["Python source files (.py)","Component definitions"],"output_types":["Reloaded component tree","Updated UI in browser"],"categories":["automation-workflow","development-tools"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"pypi_pypi-mesop__cap_4","uri":"capability://data.processing.analysis.protobuf.based.component.serialization.for.client.server.communication","name":"protobuf-based component serialization for client-server communication","description":"Mesop uses Protocol Buffers (ui.proto) to serialize the component tree and send it from the server to the browser via WebSocket. The component tree is defined in Python on the server, converted to protobuf messages, and transmitted to the client where a TypeScript renderer (type_to_component.ts) deserializes and renders the components as HTML/CSS. This approach provides type safety, efficient binary serialization, and a clear contract between server and client.","intents":["Efficiently transmit UI component trees from server to client","Ensure type safety between Python server and TypeScript client","Support versioning and backward compatibility of UI protocol","Minimize bandwidth usage for UI updates"],"best_for":["Applications with frequent UI updates","Teams wanting strong typing across server-client boundary","Deployments where bandwidth is a concern"],"limitations":["Protobuf schema changes require coordination between server and client","Debugging protobuf serialization issues requires understanding both Python and TypeScript","Binary format is not human-readable — harder to inspect network traffic","Protobuf compilation adds build complexity"],"requires":["protobuf compiler (protoc)","Python protobuf library","TypeScript protobuf runtime"],"input_types":["Component tree (Python objects)","Protobuf schema definitions (.proto files)"],"output_types":["Binary protobuf messages","Deserialized component objects in TypeScript"],"categories":["data-processing-analysis","tool-use-integration"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"pypi_pypi-mesop__cap_5","uri":"capability://code.generation.editing.built.in.component.library.with.material.design.styling","name":"built-in component library with material design styling","description":"Mesop provides a library of pre-built components (button, text, input, select, datepicker, etc.) that are styled with Material Design principles and wrapped as Python functions. These components are defined in mesop/components/ and automatically registered with the runtime. Developers can use these components by calling Python functions (e.g., mesop.button(label='Click me', on_click=handler)), which generates the appropriate protobuf messages for rendering. The component library is extensible — developers can create custom components using @component decorator.","intents":["Build UIs quickly using pre-styled Material Design components","Avoid writing CSS for common UI patterns","Create consistent, accessible UIs without design expertise","Extend the component library with custom components"],"best_for":["Rapid prototyping and MVP development","Internal tools and dashboards","Teams without dedicated designers"],"limitations":["Limited to Material Design aesthetic — difficult to customize beyond theme colors","Component library is smaller than React/Vue ecosystems","Custom styling requires CSS knowledge despite Python-first approach","No support for complex animations or transitions"],"requires":["Mesop framework","CSS support in browser","Material Design icon library (optional)"],"input_types":["Component function calls with props","Event handler functions"],"output_types":["Rendered HTML/CSS in browser","User interaction events"],"categories":["code-generation-editing","ui-framework"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"pypi_pypi-mesop__cap_6","uri":"capability://tool.use.integration.web.component.integration.for.custom.html.javascript.elements","name":"web component integration for custom html/javascript elements","description":"Mesop supports integration of custom Web Components (HTML Custom Elements) via the @web_component decorator. 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This is implemented via the type_to_component.ts renderer which has special handling for web components.","intents":["Integrate third-party JavaScript libraries (charts, maps, editors) into Mesop apps","Use existing Web Components without rewriting them in Python","Extend Mesop with custom client-side functionality","Leverage the broader JavaScript ecosystem"],"best_for":["Applications requiring specialized visualizations or interactions","Teams with JavaScript expertise wanting to reuse existing libraries","Complex UIs that need client-side interactivity"],"limitations":["Web Components must follow Web Component standards — not all JavaScript libraries are compatible","Props and events must be manually serialized/deserialized between Python and JavaScript","Debugging Web Component integration requires JavaScript knowledge","Web Component lifecycle is not fully integrated with Mesop's server-driven model"],"requires":["Web Component definition (HTML Custom Element)","@web_component decorator","JavaScript/TypeScript knowledge for custom components"],"input_types":["Web Component definitions","Props (serializable to JSON)","Event handler functions"],"output_types":["Rendered Web Component in browser","Custom events from Web Component"],"categories":["tool-use-integration","ui-framework"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"pypi_pypi-mesop__cap_7","uri":"capability://automation.workflow.google.colab.integration.for.notebook.based.development","name":"google colab integration for notebook-based development","description":"Mesop includes built-in support for running in Google Colab notebooks (mesop/colab_integration.py, notebooks/mesop_colab_getting_started.ipynb). 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