# Assemble a complete application project

This recipe follows ParcelHub's checked canonical project. It combines owned
Contracts, native One implementations, a generated Rust SDK, a framework-native
Orders Desk, tests, an exact lock, and the ordinary lifecycle without adding a
product-specific manifest or parallel build path.

The layout and commands below correspond to current owning evidence. Elided
digests and caller-owned credential inputs remain illustrative end-product
values.

## Project layout

```text
systems/system-idl/examples/parcelhub/
├── Cargo.toml
├── one.one
├── one.lock
├── one/
│   ├── contracts.one
│   ├── application.one
│   ├── system.one
│   ├── orders_get.one
│   ├── orders_place.one
│   └── orders_cancel.one
├── generated/
│   └── orders.receipt
├── src/
│   ├── generated/orders.rs
│   ├── orders_desk_terminal.rs
│   └── app/page.tsx
└── tests/
    ├── generated_sdk.rs
    └── reactive_orders.rs
```

The complete source is available in the
[ParcelHub owning example](https://github.com/muijf/one/tree/main/systems/system-idl/examples/parcelhub).

## One canonical scope entry

`one.one` contains one project declaration and no implementation item:

```one
one 1

semantic parcelhub
    domain one.project@1
    project ParcelHub@1
        source ./one/contracts.one
        source ./one/application.one
        source ./one/system.one
        source ./one/orders_get.one
        source ./one/orders_place.one
        source ./one/orders_cancel.one
        lock ./one.lock
```

The selected `.one` units remain bounded sources. Their physical co-location
does not merge semantic items, implementation claims, body grammars,
reachability, trust, or selection.

## Independent roots

The System declaration selects two roots:

```one
system ParcelHub@1
    root parcelhub_embedded
        include OrdersService
        build development
        build release
        build reproducible

    root parcelhub_orders_desk
        include OrdersDeskApplication
        source OrdersDeskApplication from parcelhub.build#OrdersDeskWeb@1
        activate parcelhub.test#OrdersDeskHealth@1
        activate parcelhub.projection#OrdersTypeScript@1
        build development
        build release
        build reproducible
```

`parcelhub_embedded` closes the native order service. `parcelhub_orders_desk`
closes the framework-native Next/TypeScript presentation, its readiness
scenario, and exact client projection. Sharing a project does not merge their
source, artifacts, providers, credentials, or grants.

## Verify the owning code

```console
cargo test -p parcelhub --all-targets
cargo check -p parcelhub --no-default-features

one init systems/system-idl/examples/parcelhub --offline
one check \
  --workspace systems/system-idl/examples/parcelhub --offline
```

The Cargo tests own generated-SDK parity, exact process-local dispatch,
operator-language uncertain-outcome behavior, and exact-key reactive query
behavior. The project check reparses and normalizes the canonical sources
through the exact lock.

## Inspect without selecting or mutating

```console
one inspect parcelhub.system#OrdersService@1 \
  --workspace systems/system-idl/examples/parcelhub --format json

one inspect parcelhub.implementation#OrdersGetOne@1 \
  --workspace systems/system-idl/examples/parcelhub --format json

one inspect root:parcelhub_embedded \
  --workspace systems/system-idl/examples/parcelhub --format json
```

These views distinguish normalized component meaning, an implementation claim,
and root reachability. Candidate visibility is not Planning selection, Build
realization, binding, or authority.

## Exercise the public lifecycle

The focused owning integration test supplies disposable provider packages and
request values in a temporary directory, then invokes the checked-in project
through the public CLI:

```console
cargo test -p one-cli --test parcelhub_lifecycle \
  parcelhub_native_one_workflow_retains_interpreter_receipt \
  -- --exact --nocapture
```

The complete release path remains:

```text
init/adopt -> invoke local -> release -> approve -> apply -> inspect -> reconcile
```

Provider packages, configuration, OCS requests, credentials, and release
evidence used by the integration test are owning test inputs. They do not
become ParcelHub source, an ambient provider catalog, or product acceptance by
mere fixture presence.

Continue with [Build a typed service](/one/examples/service),
[Use a framework-native application](/one/examples/framework-application),
[Build a durable workflow](/one/examples/durable-workflow), and
[Ship and inspect a release](/one/examples/release).