# Apps

Create, deploy, and control SingulaComp Apps from the SDK and from React.

Canonical page: https://singulacomp.ai/docs/sdk/apps

Apps are project-scoped serverless deployments. This page covers the SDK
surface: the `apps` facade on a project handle, the artifact and deployment
calls, the access calls, the exported types, and the React hooks.

For what an App is, the source kinds, the CLI, the stable URL, and cold-wake
behavior, read [Apps](/docs/feature-flags/apps).

```ts
const apps = singulacomp.project(projectId).apps;
```

> **Apps is a feature flag**
> Every Apps route answers `403` with `{ error, code: "feature_disabled", feature: "apps" }`
> until the project turns Apps on. Use `isFeatureDisabledError(error)` to branch
> on it. See [Feature flags](/docs/feature-flags).

## The apps facade

| Method | Wraps | What it does |
|---|---|---|
| `apps.list()` | `GET /projects/:pid/apps` | Lists the project's Apps |
| `apps.create(input)` | `POST …/apps` | Creates an App and assigns its stable URL |
| `apps.get(appId)` | `GET …/apps/:id` | Reads one App |
| `apps.update(appId, input)` | `PATCH …/apps/:id` | Renames it or changes machine, idle timeout, or budget |
| `apps.remove(appId)` | `DELETE …/apps/:id` | Deletes the App and its runtimes |
| `apps.start(appId)` | `POST …/apps/:id/start` | Sets `desired_state` to `running` and warms the runtime |
| `apps.stop(appId)` | `POST …/apps/:id/stop` | Suspends compute now; the next request resumes it |
| `apps.rollback(appId, deploymentId)` | `POST …/apps/:id/rollback` | Moves traffic to a ready deployment |

Artifacts are the immutable input to a deployment:

| Method | Wraps | What it does |
|---|---|---|
| `apps.artifacts.register(input)` | `POST …/apps/artifacts` | Registers an `archive` or an `oci_image`; returns the upload URL for an archive |
| `apps.artifacts.uploadArchive(bytes, options?)` | — | Registers, uploads, hashes, and finalizes one `.tar.gz` in a single call |
| `apps.artifacts.finalize(artifactId, input)` | `POST …/apps/artifacts/:id/finalize` | Confirms `sha256` and `size_bytes` for a manual upload |

Deployments are immutable and numbered:

| Method | Wraps | What it does |
|---|---|---|
| `apps.deployments.create(appId, input)` | `POST …/apps/:id/deployments` | Starts a deployment from an artifact and a source |
| `apps.deployments.list(appId)` | `GET …/apps/:id/deployments` | Lists the deployment history |
| `apps.deployments.get(appId, deploymentId)` | `GET …/deployments/:did` | Reads one deployment plus its events |
| `apps.deployments.logs(appId, deploymentId, options?)` | `GET …/deployments/:did/logs` | Reads runtime logs with a cursor |

Access is the App's own authorization policy:

| Method | Wraps | What it does |
|---|---|---|
| `apps.access.get(appId)` | `GET …/apps/:id/access` | Reads the policy. Needs `project.customize.write` |
| `apps.access.update(appId, input)` | `PATCH …/apps/:id/access` | Replaces the policy and bumps its revision |
| `apps.access.session(appId)` | `POST …/apps/:id/access-session` | Mints a five-minute URL that exchanges into a host-only cookie |

## Deploy a static site

`uploadArchive` does the whole artifact handshake: it registers the artifact,
checks it against `max_bytes`, `PUT`s the bytes, computes the SHA-256, and
finalizes.

```ts
const apps = singulacomp.project(projectId).apps;

const app = await apps.create({ slug: 'docs', name: 'Docs' });
const artifact = await apps.artifacts.uploadArchive(tarGzBytes, {
  onProgress: (uploaded, total) => console.log(`${uploaded}/${total}`),
});

const deployment = await apps.deployments.create(app.app_id, {
  artifact_id: artifact.artifact_id,
  source: { kind: 'static', spa: true },
});

console.log(app.url, deployment.status); // https://…apps.singulacomp.ai  queued
```

`create` accepts the machine and budget fields too: `cpu`, `memory_gb`,
`disk_gb`, `idle_timeout_seconds`, and `monthly_budget_usd`. Omit them for the
defaults.

Wait for the deployment by polling its status:

```ts
async function waitForReady(appId: string, deploymentId: string) {
  for (;;) {
    const { deployment } = await apps.deployments.get(appId, deploymentId);
    if (deployment.status === 'ready') return deployment;
    if (deployment.status === 'failed' || deployment.status === 'cancelled') {
      throw new Error(deployment.error ?? deployment.error_code ?? deployment.status);
    }
    await new Promise((resolve) => setTimeout(resolve, 2000));
  }
}
```

The status values are `queued`, `validating`, `building`, `provisioning`,
`checking`, `ready`, `failed`, and `cancelled`.

## Deploy an OCI image

Register the immutable image reference, then declare the process command and
the public target port:

```ts
const registered = await apps.artifacts.register({
  kind: 'oci_image',
  image: 'ghcr.io/acme/service:2026-08-07',
});

await apps.deployments.create(app.app_id, {
  artifact_id: registered.artifact.artifact_id,
  source: {
    kind: 'oci_image',
    image: 'ghcr.io/acme/service:2026-08-07',
    command: ['node', 'server.js'],
    port: 3000,
    readiness_path: '/health',
  },
});
```

`register` returns `upload: null` for an `oci_image`. Only an `archive` gets an
upload URL.

`CreateAppDeploymentInput` also accepts `environment` (non-secret runtime
values), `secrets` (runtime key to project secret name), and `provider`
(`'daytona' | 'platinum' | 'e2b'`). Omit `provider` to use the server policy.

## Read runtime logs

```ts
let cursor = 0;
for (;;) {
  const page = await apps.deployments.logs(app.app_id, deployment.deployment_id, {
    after: cursor,
    limit: 200,
  });
  for (const entry of page.entries) console.log(entry.source, entry.line);
  cursor = page.next_cursor;
  if (page.entries.length === 0) break;
}
```

Each entry carries `cursor`, `time`, `source` (`app`, `appd`, `caddy`), and
`line`.

## Your App already knows who is looking

An App hosted by SingulaComp is opened by someone SingulaComp **already signed in**. The
Apps gate authenticates them before your first byte is served, so your App needs
no login of its own — no second password, no consent screen, no redirect.

In the browser:

```ts
import { createSingulaComp, singulacompAppViewerToken } from '@singulacomp/sdk';
import { useSingulaCompAppViewer } from '@singulacomp/sdk/react';

const singulacomp = createSingulaComp({
  backendUrl: 'https://api.singulacomp.ai/v1',
  getToken: singulacompAppViewerToken(),          // the viewer's own App-scoped token
});

function Header() {
  const { status, viewer } = useSingulaCompAppViewer();
  return <span>{status === 'viewer' ? viewer.email : 'Signed out'}</span>;
}
```

On your App's server, the gate signs the identity into every request:

```ts
import { readAppViewer, createAppViewerSingulaComp } from '@singulacomp/sdk/server';

const viewer = await readAppViewer(request);
// { userId, email, groupIds, accountId, appId, accessMode, token }
if (!viewer) return new Response('Not found', { status: 404 });

// and, for an `api`-scoped App, act as them:
const singulacomp = await createAppViewerSingulaComp(request, { backendUrl });
await singulacomp.projects.list();               // their projects, their role
```

`readAppViewer` verifies an HMAC over the header with `SINGULACOMP_APP_VIEWER_SECRET`,
which SingulaComp injects into your App at deploy. A forged header never passes: the
gate deletes any client-supplied copy before forwarding, and the signature is
made with a secret derived per App.

### How much your App is told

One setting on the App's access policy — **Settings → Access** in SingulaComp, or
`viewer_token_scope` on `PATCH /projects/:id/apps/:appId/access`:

| Scope | Your App receives |
|---|---|
| `identity` (default) | The viewer's id, email and group ids, plus a `profile email` token. Enough to show each person their own data. |
| `api` | The above, and a token that acts **as** that person on the SingulaComp API — bounded by their own role. |
| `off` | Nothing. |

The token is never the user's SingulaComp session: it lasts an hour, carries only
those scopes, and every token an App minted dies when the App is deleted or its
access policy changes. `public` and `password` Apps have no signed-in SingulaComp
viewer, so they receive none of this.

An App served on its **own domain** (not `*.apps.singulacomp.ai`) has no gate in
front of it — use [Sign in with SingulaComp](/docs/sdk/sign-in) there instead.

## Manage access

```ts
await apps.access.update(app.app_id, {
  mode: 'restricted',
  member_ids: [memberId],
  group_ids: [groupId],
});

const preview = await apps.access.session(app.app_id);
window.open(preview.url); // valid for five minutes
```

`AppAccessConfig` reports `password_configured`, never the password or its
hash. Set a password with `{ mode: 'password', password }`. Each update
increments `revision`, which revokes existing App cookies.

## Types

Every type below is exported from `@singulacomp/sdk`.

| Type | What it holds |
|---|---|
| `App` | Identity, `url`, `access_mode`, `access_revision`, `desired_state`, `active_deployment_id`, `machine`, `idle_timeout_seconds`, `monthly_budget_usd`, `last_request_at`, `viewer_can_access` |
| `AppDeployment` | `version`, `status`, `source_kind`, `hosting_provider`, `runtime_spec`, `build_spec`, `error_code`, `attempt_count`, `created_by`, `actor_type`, `source_session_id` |
| `AppDeploymentDetail` | One `deployment` plus its `events` |
| `AppAccessConfig` | `mode`, `revision`, `member_ids`, `group_ids`, `password_configured` |
| `AppAccessMode` | `'private' \| 'project' \| 'restricted' \| 'public' \| 'password'` |
| `AppSource` | `StaticAppSource \| BundleAppSource \| DockerfileAppSource \| OciImageAppSource` |
| `AppArtifact` | `kind`, `status`, `sha256`, `size_bytes`, `image_reference` |
| `AppLogEntry` · `AppLogsResponse` | One log line, and one page plus `next_cursor` |

`viewer_can_access` answers whether the caller may OPEN the App, which is not
the same as whether they can see it listed. A project manager sees every App in
the project so a private one stays manageable when its creator leaves. Check
this field before asking for an access session. Treat `undefined` as unknown,
not as denied.

`AppAccessMode` is a per-resource visibility setting on top of the role model,
not a role. `restricted` names users and groups — the same principal types the
role model uses. See
[Accounts & access](/docs/accounts#per-feature-access-settings).

`DockerfileAppSource` and `OciImageAppSource` require `command` and `port`.
`StaticAppSource` and `BundleAppSource` do not.

## React hooks

`@singulacomp/sdk/react` exports three hooks for Apps.

### useProjectApps(projectId)

The project's App inventory plus its lifecycle mutations. Every mutation
invalidates the inventory on success.

```tsx
import { useProjectApps } from '@singulacomp/sdk/react';

function AppList({ projectId }: { projectId: string }) {
  const apps = useProjectApps(projectId);
  if (!apps.data) return null;

  return (
    <ul>
      {apps.data.map((app) => (
        <li key={app.app_id}>
          <a href={app.url}>{app.slug}</a>
          <button onClick={() => apps.stop.mutate(app.app_id)}>Stop</button>
        </li>
      ))}
    </ul>
  );
}
```

It returns the query fields plus `create`, `update`, `start`, `stop`, and
`remove`.

### useAppDeployments(projectId, appId)

The immutable deployment history, refetched every 5 s so a running build
advances on its own.

```tsx
const deployments = useAppDeployments(projectId, appId);

await deployments.deploy.mutateAsync({
  artifact_id: artifact.artifact_id,
  source: { kind: 'static', spa: true },
});
await deployments.rollback.mutateAsync(previousDeploymentId);
```

Both mutations invalidate the deployment list and the App inventory.

### useAppAccess(projectId, appId, options?)

The access policy and a short-lived access session. Both halves are separate
queries, and each one is optional.

```tsx
const access = useAppAccess(projectId, appId, {
  policy: canEditAccess,
  session: app.viewer_can_access,
});

access.policy.data;  // AppAccessConfig
access.session.data; // { url, expires_at }
await access.update.mutateAsync({ mode: 'project' });
```

| Option | Default | Use `false` when |
|---|---|---|
| `policy` | `true` | The surface only previews the App. `GET …/access` is an administrative read and answers `403` for a caller without project-manager permissions. |
| `session` | `true` | The caller may see the App but not open it. Pass `app.viewer_can_access`. |

A grid of Apps that leaves both options at `true` fires one policy read and one
session mint per App, and each is a `403` for a member who may not open that
App.

## Errors

```ts
import { featureDisabledKey, isFeatureDisabledError } from '@singulacomp/sdk';

try {
  await singulacomp.project(projectId).apps.list();
} catch (error) {
  if (isFeatureDisabledError(error)) {
    console.log(`${featureDisabledKey(error)} is off for this project`);
  }
}
```

Other answers you should handle: `409` for a duplicate slug, `402` with
`app_quota_exceeded` when the account is at its App limit, and `400` with
`app_machine_out_of_range` or `app_budget_out_of_range` for a spec outside its
bounds.