# `Ash.Can`
[🔗](https://github.com/ash-project/ash/blob/v3.33.1/lib/ash/can.ex#L5)

Contains the Ash.can function logic.

# `check_entry`

```elixir
@type check_entry() :: subject() | {subject(), Keyword.t()}
```

# `checks`

```elixir
@type checks() :: [check_entry()] | [{atom(), check_entry()}]
```

# `subject`

```elixir
@type subject() ::
  Ash.Query.t()
  | Ash.Changeset.t()
  | Ash.ActionInput.t()
  | {Ash.Resource.t(), atom() | Ash.Resource.Actions.action()}
  | {Ash.Resource.t(), atom() | Ash.Resource.Actions.action(), input :: map()}
  | {Ash.Resource.Record.t(), atom() | Ash.Resource.Actions.action()}
  | {Ash.Resource.Record.t(), atom() | Ash.Resource.Actions.action(),
     input :: map()}
```

# `can`

```elixir
@spec can(subject(), Ash.Domain.t(), Ash.actor() | Ash.Scope.t(), Keyword.t()) ::
  {:ok, boolean() | :maybe}
  | {:ok, boolean(), term()}
  | {:ok, boolean(), Ash.Changeset.t(), Ash.Query.t()}
  | {:error, Ash.Error.t()}
```

Returns a an ok tuple if the actor can perform the action, query, or changeset,
an error tuple if an error happens, and a ok tuple with maybe if maybe is set to true
or not set.

You should prefer to use `Ash.can/3` over this module, directly.

Note: `maybe_is` is set to `:maybe`, if not set.

# `can?`

```elixir
@spec can?(subject(), Ash.Domain.t(), Ash.Resource.Record.t(), Keyword.t()) ::
  boolean() | no_return()
```

Returns whether an actor can perform an action, query, or changeset.

You should prefer to use `Ash.can?/3` over this module, directly.

Can raise an exception if return_forbidden_error is truthy in opts or there's an error.

# `can_do_all`

```elixir
@spec can_do_all(checks(), Ash.actor() | Ash.Scope.t(), Keyword.t()) ::
  {:ok, [boolean() | :maybe] | map()} | {:error, Ash.Error.t()}
```

Returns whether an actor can perform each of the given actions.

You should prefer to use `Ash.can_do_all/3` over this module, directly.

Returns `{:ok, results}` where `results` is a list (when `checks` is a list) or a map
(when `checks` is a keyword list). Each value is `true`, `false`, or `:maybe`.

Each entry in `checks` is the same shape accepted by `can/3`, or `{subject, opts}`
to provide per-check options. Per-check options are merged on top of the shared
options, so values like `tenant` and `context` only need to be provided once.

# `can_do_all?`

```elixir
@spec can_do_all?(checks(), Ash.actor() | Ash.Scope.t(), Keyword.t()) ::
  boolean() | no_return()
```

Returns whether an actor can perform all of the given actions.

You should prefer to use `Ash.can_do_all?/3` over this module, directly.

Each entry in `checks` is the same shape accepted by `can?/3`, or `{subject, opts}`
to provide per-check options. Per-check options are merged on top of the shared
options, so values like `tenant` and `context` only need to be provided once.

When `checks` is a keyword list, use `Ash.can_do_all/3` to get a map of results
keyed by the provided names.

Can raise an exception if `return_forbidden_error?` is truthy in opts or there's an error.

# `evaluate_field_policies`

```elixir
@spec evaluate_field_policies(
  subject() | Ash.Resource.t(),
  Ash.Domain.t(),
  Ash.actor() | Ash.Scope.t(),
  [atom()],
  Keyword.t()
) ::
  {:ok, %{required(atom()) => boolean() | {:filter, term()}}}
  | {:error, Ash.Error.t()}
```

Evaluates field policies for the given fields in the context of the given
action, query, or changeset, without needing any records in hand.

You should prefer to use `Ash.can_see_fields?/4` or `Ash.can_see_fields/4`
over this module, directly.

Returns `{:ok, results}` where each requested field maps to `true`, `false`,
or `{:filter, expr}` when its visibility depends on the record it is read
from (i.e its field policies use filter checks).

When a record is provided via the `:data` option (or the subject is a
`{record, read_action}` tuple), record-dependent fields are instead resolved
by evaluating their filters against that record. With `run_queries?: false`,
filters that cannot be resolved from the record's in-memory values remain
`{:filter, expr}` for the caller to collapse.

---

*Consult [api-reference.md](api-reference.md) for complete listing*