# Hub Core runtime

The initial runtime scaffold implements the packaging decision in ADR-0001 and
the minimal vertical in `HUB-WP-0004-T04`. It is a conformance and absorption
base, not yet the production replacement for Core Hub.

## Processes

The `runtime` dependency extra installs one `hub-core` command with three
process modes:

```bash
uv sync --extra runtime
hub-core api --host 127.0.0.1 --port 8010
hub-core mcp --host 127.0.0.1 --port 8011 --api-base http://127.0.0.1:8010
hub-core migrate head --database-url postgresql+asyncpg://...
```

The migration command converts the async PostgreSQL URL for the packaged
synchronous Alembic environment. Production must run migrations explicitly;
the API does not auto-create tables.

## Runtime ports

| Port | Initial path | Behavior |
| --- | --- | --- |
| `port.registry` | `POST /ports/registry/registrations` | Validates and idempotently records a descriptor/manifest package |
| `port.messaging` | `GET/POST /ports/messaging/messages` | Addressed messages with optional conversation identity |
| `port.events.progress` | `POST /ports/events/progress` | Accepts only cataloged progress-family events |
| `port.events.interaction` | `POST /ports/events/interaction` | Accepts only cataloged interaction-family events |
| `port.projection.query` | `GET /ports/projections/{id}` | Rebuildable registry/message/event projections with provenance |

Available projection ids are `hub_registry`, `messages`, `progress_events`, and
`interaction_events`. The two event families use distinct stores and cannot be
submitted through each other's endpoint.

## Backend boundary and readiness

The app is created with an injected `PortStore`. T04 ships
`InMemoryPortStore` for deterministic tests and local contract smokes. It is
ephemeral and is not a production authority.

`GET /healthz` proves the process is alive. `GET /readyz` fails with HTTP 503
when the active backend does not match `HUB_CORE_BACKEND`, or when the memory
backend is used without explicit permission. Development and test permit it by
default; the OCI image sets production-safe defaults:

```text
HUB_CORE_ENV=production
HUB_CORE_BACKEND=memory
HUB_CORE_ALLOW_EPHEMERAL=0
```

Therefore the image is deliberately not production-ready until a durable
backend lands in an absorption slice. A local image smoke may opt in with
`HUB_CORE_ALLOW_EPHEMERAL=1`.

## OCI image

The `Containerfile` uses `uv.lock` with `uv sync --frozen`, installs the runtime
extra, runs as UID/GID 10001, includes OCI version/revision labels, and exposes
API port 8010 plus MCP port 8011.

```bash
docker build -f Containerfile \
  --build-arg VERSION=0.2.0 \
  --build-arg VCS_REF="$(git rev-parse HEAD)" \
  -t hub-core:dev .

docker run --rm -p 8010:8010 \
  -e HUB_CORE_ALLOW_EPHEMERAL=1 \
  hub-core:dev
```

Deployment charts, secrets, rollout policy, and live evidence remain owned by
the rapp/platform repositories. `/api/v2` data and compatibility routes remain
on Core Hub until the T06/CORE-WP-0010 dual-run slices move them.

## Conformance

The public-port Tier 2/3 scaffold is documented in `docs/conformance.md`. Run
it against an isolated runtime with `hub-core conformance --base-url <url>`.

## Core Hub absorption

`docs/core-hub-absorption-plan.md` defines the capability-sized `/api/v2`
route and data move order, single-writer dual-run controls, evidence gates,
rollback, and final cutover criteria shared with `CORE-WP-0010`.