# Packages Packages are directories with a `Cplus.toml`, source modules, and optional tests, documentation, link metadata, and platform variants. Add a package with `cpc pm add`; see [Modules and packages](/docs/modules-and-packages) and [Package manager](/docs/package-manager) for resolution and manifest rules. ## Core library and data - [stdlib](/docs/packages/stdlib) — collections, text, I/O, concurrency, async runtime pieces, files, networking, and platform shims. - [json](/docs/packages/json) — JSON parsing and serialization. - [sqlite](/docs/packages/sqlite) — `Connection` and `Statement`; raw bindings are available as `sqlite/raw`. - [arena](/docs/packages/arena) — growable bump allocator. - [static_arena](/docs/packages/static_arena) — fixed-capacity allocator stored in the value itself, with no heap allocation. - [uuid](/docs/packages/uuid) and [log](/docs/packages/log) — identifiers and structured logging. ## Facet applications - [facet](/docs/packages/facet) — platform-neutral UI tree, elements, components, screens, services, and navigation vocabulary. - [facet_runtime](/docs/packages/facet_runtime) — application entry point, named windows, routes, history, and backend installation. - [facet_appkit](/docs/packages/facet_appkit) — macOS backend. - [facet_uikit](/docs/packages/facet_uikit) — iOS backend. - [facet_android](/docs/packages/facet_android) — Android backend. - [facet_gtk](/docs/packages/facet_gtk) — GTK 4 backend for Linux. - [facet_win32](/docs/packages/facet_win32) — native Win32 backend. - [flex_layout](/docs/packages/flex_layout) — shared Flexbox and Grid layout engine. - [inspector](/docs/packages/inspector) — mounted-tree inspection and editing for development. ## Agent surface - [agent_core](/docs/packages/agent_core) — identities, exposure, capability grants, sensitivity tiers, outcomes, events, and backend interface. - [facet_agent](/docs/packages/facet_agent) — optional agent integration for Facet applications. - [agent_mcp](/docs/packages/agent_mcp) and [agent_inapp](/docs/packages/agent_inapp) — external JSON-RPC/MCP and in-process access. - [agent_appkit](/docs/packages/agent_appkit), [agent_uikit](/docs/packages/agent_uikit), [agent_android](/docs/packages/agent_android), [agent_gtk](/docs/packages/agent_gtk), and [agent_win32](/docs/packages/agent_win32) — platform tree adapters. - [agent_jwt](/docs/packages/agent_jwt) — token verification for grant policies. See [Agent surface](/docs/agent-surface) for the shared authorization model. ## Native capabilities - [notifications](/docs/packages/notifications) and [applinks](/docs/packages/applinks) - [camera](/docs/packages/camera), [location](/docs/packages/location), and [sensors](/docs/packages/sensors) - [biometrics](/docs/packages/biometrics), [securestore](/docs/packages/securestore), and [permissions](/docs/packages/permissions) - [filepicker](/docs/packages/filepicker), [haptics](/docs/packages/haptics), and [share](/docs/packages/share) - [http](/docs/packages/http) and [fswatch](/docs/packages/fswatch) - [terminal](/docs/packages/terminal) — terminal screen model and native widgets on macOS and Linux. Each package page records its platform coverage and explicit unsupported outcomes. ## Platform bindings - Apple: [appkit](/docs/packages/appkit), [uikit](/docs/packages/uikit), [foundation](/docs/packages/foundation), [quartzcore](/docs/packages/quartzcore), [metal](/docs/packages/metal), [avfoundation](/docs/packages/avfoundation), [corelocation](/docs/packages/corelocation), [coremotion](/docs/packages/coremotion), [coreml](/docs/packages/coreml), [localauthentication](/docs/packages/localauthentication), [mapkit](/docs/packages/mapkit), and [vision](/docs/packages/vision). - Linux/GTK: [gtk4](/docs/packages/gtk4), [adwaita](/docs/packages/adwaita), [gobject](/docs/packages/gobject), and their GLib/GIO/Cairo/Pango support packages. - Windows: [win32](/docs/packages/win32). - Android: [android_view](/docs/packages/android_view) and [jni](/docs/packages/jni). - Embedded: [espidf](/docs/packages/espidf). ## Numerics, GPU, and AI - [simd](/docs/packages/simd), [cblas](/docs/packages/cblas), and [accelerate](/docs/packages/accelerate) - [metal](/docs/packages/metal) and [cuda](/docs/packages/cuda) - [llama_cpp](/docs/packages/llama_cpp) and [coreai](/docs/packages/coreai) ## Real-time - [rt](/docs/packages/rt) — fixed pools, rings, and other primitives used with the compiler's real-time contracts. - [rt_darwin](/docs/packages/rt_darwin) — Darwin-specific real-time support.