# Cloud — Docs

> Developer documentation for building and operating Cloud applications.

## Start

- [Introduction](https://cloud.k2b.dev/en/docs.md): Build an application and find the Cloud platform APIs it needs.
- [Platform model](https://cloud.k2b.dev/en/docs/overview.md): Understand why Cloud applications are independent services and where the platform boundary ends.
- [Building blocks](https://cloud.k2b.dev/en/docs/building-blocks.md): Match a third-party application task to its supported public Cloud entry point.

## Build an app

- [Overview](https://cloud.k2b.dev/en/docs/build.md): Build an independently released application against Cloud's public runtime contract.
- [First application](https://cloud.k2b.dev/en/docs/build/getting-started.md): Build and verify a standalone API-only application with the published Cloud package.
- [Define an application](https://cloud.k2b.dev/en/docs/build/define-app.md): Declare application identity, routes, navigation, and platform integrations with defineApp().
- [Application lifecycle](https://cloud.k2b.dev/en/docs/build/lifecycle.md): Start the service, prepare required state, run process work, and stop cleanly.
- [Routes and discovery](https://cloud.k2b.dev/en/docs/build/routing.md): Publish route prefixes and make an application reachable through the gateway.
- [Internationalization](https://cloud.k2b.dev/en/docs/build/internationalization.md): Add translations and locale-aware formatting without breaking Cloud SSR, islands, errors, Help, widgets, or capabilities.
- [Product language and tone](https://cloud.k2b.dev/en/docs/build/product-language-and-tone.md): Write clear English and German labels, feedback, errors, notifications, and Help without changing product meaning.

## Server

- [Overview](https://cloud.k2b.dev/en/docs/server.md): Follow one request from the gateway to a typed response.
- [Request middleware](https://cloud.k2b.dev/en/docs/server/middleware.md): Add the request context and transport policies an application needs.
- [Typed HTTP APIs](https://cloud.k2b.dev/en/docs/server/http.md): Validate a Hono endpoint, publish its contract, and use its typed browser client.
- [Services and Result](https://cloud.k2b.dev/en/docs/server/services-and-results.md): Keep business rules reusable and return explicit failures.
- [Locale and time](https://cloud.k2b.dev/en/docs/server/locale-and-time.md): Resolve the request locale and timezone once and reuse them for formatting, SSR, and capability metadata.
- [Pagination and filtering](https://cloud.k2b.dev/en/docs/server/pagination-and-filtering.md): Validate list state and apply it before data leaves the server.

## Identity and access

- [Overview](https://cloud.k2b.dev/en/docs/identity.md): Separate credential, route, and resource decisions in an application.
- [Request identity](https://cloud.k2b.dev/en/docs/identity/authentication.md): Resolve Cloud credentials into the actor and access subject used by an application.
- [Route policies](https://cloud.k2b.dev/en/docs/identity/route-policies.md): Choose who may enter an API or SSR route before the service checks its resource.
- [Resource authorization](https://cloud.k2b.dev/en/docs/identity/authorization.md): Resolve resource grants in application services for users, groups, service accounts, and public callers.
- [Resource API keys](https://cloud.k2b.dev/en/docs/identity/resource-api-keys.md): Create API keys for one application resource without bypassing resource authorization.
- [OAuth](https://cloud.k2b.dev/en/docs/identity/oauth.md): Configure OAuth clients and choose authorization code or client credentials.
- [Background mandates](https://cloud.k2b.dev/en/docs/identity/background-mandates.md): Let durable app work call another application without storing a user's session or API key.
- [Public access](https://cloud.k2b.dev/en/docs/identity/public-and-anonymous-access.md): Expose selected routes without creating another identity or permission model.

## Platform services

- [Document extraction](https://cloud.k2b.dev/en/docs/platform/document-extraction.md): Convert authorized document bytes to bounded Markdown in application server code.
- [Overview](https://cloud.k2b.dev/en/docs/platform.md): Choose the platform boundary that removes shared infrastructure from an application.
- [Settings](https://cloud.k2b.dev/en/docs/platform/settings.md): Define application settings and access them in requests, jobs, and lifecycle hooks.
- [Logging](https://cloud.k2b.dev/en/docs/platform/logging.md): Write structured application logs with safe metadata.
- [Notifications](https://cloud.k2b.dev/en/docs/platform/notifications.md): Define, send, and inspect typed notifications.
- [Tracing](https://cloud.k2b.dev/en/docs/platform/tracing.md): Follow one request across application and platform boundaries.
- [Audit events](https://cloud.k2b.dev/en/docs/platform/audit-events.md): Record security-relevant and administrative actions as durable audit evidence.
- [Types, Queries & Actions](https://cloud.k2b.dev/en/docs/platform/capabilities.md): Publish a small, versioned RPC surface for cross-app calls, agents, CLI, and MCP.
- [Universal search](https://cloud.k2b.dev/en/docs/platform/search.md): Project focused application Queries into the shared Cloud search.
- [Resource copy and paste](https://cloud.k2b.dev/en/docs/platform/resource-references.md): Preserve stable Cloud resource identity across application clipboard interactions.
- [MCP server](https://cloud.k2b.dev/en/docs/platform/mcp.md): Connect MCP clients to live Cloud capabilities and registered app Help.
- [Dashboard widgets](https://cloud.k2b.dev/en/docs/platform/dashboard-widgets.md): Add application-owned information to the shared Cloud dashboard.
- [In-product Help](https://cloud.k2b.dev/en/docs/platform/help.md): Declare app-owned Markdown once for the shared Help UI, full-page Help, Assistant, and MCP.
- [PDF and templates](https://cloud.k2b.dev/en/docs/platform/pdf-and-templates.md): Render documents from application data with shared template and PDF services.
- [CLI modules](https://cloud.k2b.dev/en/docs/platform/cli-modules.md): Expose application operations through the shared cld command-line interface.

## Data

- [Overview](https://cloud.k2b.dev/en/docs/data.md): Decide which data belongs to an application and which data belongs to the platform.
- [Postgres queries](https://cloud.k2b.dev/en/docs/data/postgres-queries.md): Query application-owned Postgres data with the shared database connection.
- [Public resource IDs](https://cloud.k2b.dev/en/docs/data/public-resource-identifiers.md): Decide whether an application needs compact public IDs and keep one identity consistent across its public surfaces.
- [Migrations and transactions](https://cloud.k2b.dev/en/docs/data/migrations-and-transactions.md): Evolve application schemas safely and keep related writes atomic.
- [Secrets and state](https://cloud.k2b.dev/en/docs/data/secrets-and-persistent-state.md): Store sensitive configuration and durable application state in the correct platform service.

## Automation

- [Overview](https://cloud.k2b.dev/en/docs/automation.md): Choose the smallest execution model that preserves the work and recovery guarantees you need.
- [Lifecycle work](https://cloud.k2b.dev/en/docs/automation/lifecycle-background-work.md): Start and stop simple background work with the application process.
- [Jobs and queues](https://cloud.k2b.dev/en/docs/automation/jobs-and-queues.md): Run asynchronous work and control how tasks wait for workers.
- [Schedulers](https://cloud.k2b.dev/en/docs/automation/schedulers.md): Run recurring work without coupling it to HTTP requests.
- [Topics and live events](https://cloud.k2b.dev/en/docs/automation/topics-and-live-events.md): Publish transient events to application processes and connected browsers.
- [Coordination primitives](https://cloud.k2b.dev/en/docs/automation/coordination-primitives.md): Coordinate distributed application instances with rate limits, mutexes, and ephemeral state.
- [Workflow overview](https://cloud.k2b.dev/en/docs/automation/workflow-overview.md): Understand when durable workflows are the correct automation model.
- [Author workflows](https://cloud.k2b.dev/en/docs/automation/author-and-publish-workflows.md): Build a workflow definition and publish a version that can be executed.
- [Start workflow runs](https://cloud.k2b.dev/en/docs/automation/emit-events-and-start-runs.md): Start durable workflow runs from domain events or direct application requests.
- [Effects and retry](https://cloud.k2b.dev/en/docs/automation/effects-retry-and-reconciliation.md): Make external side effects recoverable when workflow steps retry or workers crash.
- [Workflow testing](https://cloud.k2b.dev/en/docs/automation/workflow-observability-and-testing.md): Inspect workflow runs and verify application actions without hiding runtime failures.

## Frontend

- [Overview](https://cloud.k2b.dev/en/docs/frontend.md): Keep server authority while adding the smallest useful browser interaction to a Cloud application.
- [SSR pages and routing](https://cloud.k2b.dev/en/docs/frontend/ssr-pages-and-routing.md): Render application pages on the server and map them to explicit routes.
- [Layout and navigation](https://cloud.k2b.dev/en/docs/frontend/layout-and-navigation.md): Place application pages in the shared Cloud layout and navigation.
- [Application shells](https://cloud.k2b.dev/en/docs/frontend/application-shells.md): Choose the shared shell that matches an application's information structure.
- [Islands and hydration](https://cloud.k2b.dev/en/docs/frontend/islands-and-hydration.md): Add browser interactivity to server-rendered pages without turning the whole page into a client application.
- [Clients and mutations](https://cloud.k2b.dev/en/docs/frontend/browser-clients-and-mutations.md): Call typed application APIs and handle user-initiated writes consistently.
- [Server-backed state](https://cloud.k2b.dev/en/docs/frontend/server-backed-island-state.md): Keep an authorized SSR snapshot current with owner-local Solid queries, pagination, mutations, and live invalidation.
- [URL state and navigation](https://cloud.k2b.dev/en/docs/frontend/url-state-and-navigation.md): Keep durable view state in the URL and navigate without losing server authority.
- [Realtime UI](https://cloud.k2b.dev/en/docs/frontend/realtime-ui.md): Update an open page from application events while preserving reload and recovery behavior.
- [Forms and feedback](https://cloud.k2b.dev/en/docs/frontend/forms-prompts-and-feedback.md): Collect input and show mutation progress, cancellation, success, and errors.
- [Styling and accessibility](https://cloud.k2b.dev/en/docs/frontend/styling-and-accessibility.md): Apply Cloud's visual and interaction rules without forking shared primitives.
- [Frontend testing](https://cloud.k2b.dev/en/docs/frontend/testing.md): Test server-rendered pages, interactive islands, navigation, and application states.

## AI

- [Overview](https://cloud.k2b.dev/en/docs/ai.md): Choose the smallest model runtime while keeping application authority explicit.
- [Resources and access](https://cloud.k2b.dev/en/docs/ai/resources-and-access.md): Attach Cloud resources without moving domain authorization into AI Core.
- [Models and providers](https://cloud.k2b.dev/en/docs/ai/models-and-providers.md): Configure models and providers without exposing credentials to application clients.
- [Chat and streaming](https://cloud.k2b.dev/en/docs/ai/chat-runtime-and-streaming.md): Create personal conversations, save composer drafts, and stream agent work.
- [Tools and approvals](https://cloud.k2b.dev/en/docs/ai/tools-and-approvals.md): Let models request application actions while keeping authorization and approval explicit.
- [Files, Projects, Skills, and personalization](https://cloud.k2b.dev/en/docs/ai/files-projects-and-personalization.md): Give AI controlled access to chat files, shared Project context and Skills, and durable personal preferences.
- [Structured and background AI](https://cloud.k2b.dev/en/docs/ai/structured-and-background-ai.md): Run validated model tasks outside an interactive chat request.
- [Usage and feedback](https://cloud.k2b.dev/en/docs/ai/usage-and-feedback.md): Filter AI usage, compare users and models, and inspect feedback and failed runs in Admin or the CLI.
- [Chat interface](https://cloud.k2b.dev/en/docs/ai/chat-interface.md): Present conversation state, tools, approvals, and failures with the shared chat controller and components.

## Operations

- [Overview](https://cloud.k2b.dev/en/docs/operations.md): Develop and operate an independent Cloud application through the shared gateway.
- [Monorepo development](https://cloud.k2b.dev/en/docs/operations/monorepo-development.md): Develop a built-in application inside the Cloud monorepo.
- [Standalone development](https://cloud.k2b.dev/en/docs/operations/standalone-development.md): Develop an independent application against the published Cloud package.
- [Deployment requirements](https://cloud.k2b.dev/en/docs/operations/deployment-requirements.md): Choose Cloud applications and identify their infrastructure, secrets, feature dependencies, startup order, and verification checks.
- [Build and deploy](https://cloud.k2b.dev/en/docs/operations/build-and-deploy.md): Build a standalone application image and connect it to a Cloud deployment.
- [Snapshot worker cutover](https://cloud.k2b.dev/en/docs/operations/notebooks-snapshot-cutover.md): Move existing Notebook snapshot work to the ordered worker without losing accepted edits.
- [Runtime configuration](https://cloud.k2b.dev/en/docs/operations/runtime-configuration.md): Configure application containers, platform connections, and environment-specific values.
- [Identity keys](https://cloud.k2b.dev/en/docs/operations/identity-key-operations.md): Operate Core-owned signing keys, rotation, rewrap, and emergency revocation.
- [Scaling and shutdown](https://cloud.k2b.dev/en/docs/operations/scaling-and-shutdown.md): Run multiple application instances and shut them down without losing work.
- [Observability](https://cloud.k2b.dev/en/docs/operations/observability.md): Use logs, traces, metrics, and health data to operate Cloud applications.
- [NATS operations](https://cloud.k2b.dev/en/docs/operations/nats-operations.md): Inspect NATS infrastructure, investigate Sync failures, and configure independent outage monitoring.
- [FreeIPA](https://cloud.k2b.dev/en/docs/operations/freeipa.md): Connect a Cloud deployment to FreeIPA identity infrastructure.
- [Linux identities](https://cloud.k2b.dev/en/docs/operations/linux-identities.md): Assign local UID, GID, home and shell attributes and backfill existing accounts without changing authentication.
- [Troubleshooting](https://cloud.k2b.dev/en/docs/operations/troubleshooting.md): Diagnose common application registration, request, data, and runtime failures.

## Reference

- [Overview](https://cloud.k2b.dev/en/docs/reference.md): Look up stable Cloud application contracts and compatibility information.
- [API surface](https://cloud.k2b.dev/en/docs/reference/api-surface.md): Choose a supported Cloud import and check its runtime and stability.
- [Route conventions](https://cloud.k2b.dev/en/docs/reference/route-conventions.md): Look up the route prefixes reserved by Cloud and those owned by applications.
- [Settings reference](https://cloud.k2b.dev/en/docs/reference/settings-kinds-and-environment.md): Look up supported setting kinds, defaults, validation, and environment behavior.
- [Vocabulary and statuses](https://cloud.k2b.dev/en/docs/reference/vocabulary-and-statuses.md): Look up the terms and status values used across Cloud application APIs.
- [Deprecations](https://cloud.k2b.dev/en/docs/reference/deprecations-and-migrations.md): Find removed or superseded APIs and the supported migration path.

## Contributing

- [Document core changes](https://cloud.k2b.dev/en/docs/contributing/document-cloud-core-changes.md): Keep developer docs, UI examples, and the Fibel-backed Cloud skill aligned with core changes.
- [Identity performance](https://cloud.k2b.dev/en/docs/contributing/identity-performance.md): Measure JWT search latency and verify identity I/O with real authentication.
- [OAuth upgrade verification](https://cloud.k2b.dev/en/docs/contributing/oauth-upgrade-verification.md): Check the public OAuth contract against the pre-JWT implementation with an isolated HTTP reference client.

## Full text

- [All pages in one file](https://cloud.k2b.dev/en/docs/llms-full.txt)