# Examples and recipes

These recipes show the finished One product through complete, task-oriented
slices. Start with a goal, follow its authored meaning into implementation and
operation, and keep every physical choice behind its owning contract.

All `.one` and language API snippets in this section are illustrative end-product
syntax. They demonstrate the product contract and intended
ergonomics; the owning language packages and executable examples remain the
source of exact implementation evidence.

Commands under an **Executable evidence** heading are current, copyable owning
checks. Other command snippets describe the finished product interface and do
not claim that a current package implements that capability. This distinction
keeps the end-product documentation useful without turning an illustrative
coordinate, option, or output into false repository evidence.

## Choose a recipe

| If you want to… | Follow |
| --- | --- |
| See how every file and root fits together | [Assemble a complete project](/one/examples/complete-project) |
| Define and invoke a typed operation | [Build a service](/one/examples/service) |
| Add governed persistent state | [Build a data-backed service](/one/examples/data-service) |
| Project an operation to HTTP or streaming | [Project communication boundaries](/one/examples/communication) |
| Export and consume Rust or TypeScript clients | [Generate and use an SDK](/one/examples/sdk-client) |
| Coordinate retries, timers, and human approval | [Build a durable workflow](/one/examples/durable-workflow) |
| Present typed places and intents in a browser | [Build a One Web application](/one/examples/one-web) |
| Use One from Next.js without pretending it is One Web | [Use a framework-native application](/one/examples/framework-application) |
| Build a mobile, desktop, terminal, or device client | [Build other application targets](/one/examples/application-targets) |
| Give an agent bounded typed tools | [Build an agent](/one/examples/agent) |
| Bound concurrent work and resource lifetimes | [Manage resources and execution](/one/examples/resources-execution) |
| Grant one effect and deliver a protected secret | [Grant authority and deliver secrets](/one/examples/authority-secrets) |
| Connect an external system without surrendering ownership | [Build a provider adapter](/one/examples/provider-adapter) |
| Project commands and events to a broker | [Use messaging](/one/examples/messaging) |
| Derive analytical, search, and vector views | [Build data projections](/one/examples/analytical-search-data) |
| Release a bounded customer control plane | [Build a multi-tenant platform](/one/examples/multi-tenant-platform) |
| Create organization-owned meaning | [Define a semantic domain](/one/examples/semantic-domain) |
| Change a contract and its stored data | [Evolve and migrate](/one/examples/change-migration) |
| Restore, fail over, or roll back | [Recover a release](/one/examples/recovery) |
| Connect live signals to causal facts | [Observe and trace history](/one/examples/observability-history) |
| Sign, admit, publish, and revoke | [Govern the supply chain](/one/examples/supply-chain) |
| Manage workspace and package source changes | [Use source transactions](/one/examples/workspace-source-transactions) |
| Authenticate CI without a stored production secret | [Use workload identity](/one/examples/workload-identity) |
| Bind accessibility, performance, and CI to a release | [Qualify a release](/one/examples/release-qualification) |
| Keep negative outcomes distinct | [Handle failures](/one/examples/failure-handling) |
| Produce and inspect a governed release | [Ship and inspect a release](/one/examples/release) |

## Read examples as one lifecycle

Every recipe uses the same boundaries:

```text
authored declaration
  -> checked owner value
  -> selected implementation and providers
  -> exact Build artifacts
  -> authorized placement and effects
  -> observations, receipts, and causal history
```

A declaration is never executable authority. A code body is never selected
merely because it exists. A provider package is inert until one root selects
it. A successful command output is not deployment evidence unless its owner
record and receipts remain resolvable.

Use [Build your first system](/one/start/first-system) for the shortest guided
introduction, then return here for the capability you need.