# The app itself

> Read the app's id, slug, mode and mount path, and ask what an administrator attached.

Source: /toft-docs/latest/cli/sdk/app/

## Who am I

```python
toft.app.id, toft.app.slug, toft.app.name, toft.app.mode, toft.app.base_path
```
```js
toft.app.id;  toft.app.slug;   // plain properties
await toft.app.mode();         // also name(), basePath()
```
```go
self, err := toft.App.Self(ctx)   // self.ID, .Slug, .Name, .Mode, .BasePath
```
```r
info <- app_info()                # info$slug, info$base_path, ...
app_base_path()
```

> **Node: id and slug are properties, the rest are async**
>
> In Node, `toft.app.id` and `toft.app.slug` are plain strings — calling them,
> `toft.app.slug()`, is a `TypeError`. `name()`, `mode()` and `basePath()` return
> a Promise: forget the `await` and a template renders `[object Promise]`. In
> Python they are all plain properties.

The answer is fetched once and cached for the life of the process. Call
`toft.app.refresh()` (Go: `toft.App.Refresh()`) to re-read it.

### Base path

Your app is served under `/apps/<slug>`, and `base_path` is that prefix. Build
every link and form action from it. Redirects (`Location`) must not include it;
the proxy adds it. It falls back to the `BASE_PATH` variable, so it is never empty
on a mounted app. See [Environment variables](/toft-docs/latest/cli/reference/environment.md).

### Mode

`mode` is `shared` or `isolated` for **this** running workload, taken from the
deployment that started it. It is correct on the first request.

## What did an administrator attach

```python
if toft.app.can("email"): ...
```
```js
if (await toft.app.can("email")) { … }
```
```go
ok, err := toft.App.Can(ctx, "email")
```

`can()` takes an integration name (`email`, `slack`) or a full capability
(`email.send`). `toft.app.capabilities` lists everything attached.

Check at startup. An app that does can tell someone "email is not enabled for
this app" on a settings screen instead of failing later in a log.

A kind nobody attached is absent, not switched off. The fix is to ask an
administrator, not to retry.

R has no `can()`. `app_info()` includes the capabilities the install granted.

## What the app is not told

- Which channel, folder or address an integration points at. That belongs to
  the administrator.
- Whether a viewer is a Toft administrator, from the role alone. Use
  [`who`](/toft-docs/latest/cli/sdk/viewer.md).
- Other people's group memberships.