> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vanna.finance/llms.txt
> Use this file to discover all available pages before exploring further.

# Controller Facade

> Current testnet implementation, behavior, authorization, and Rust signatures.

ControllerFacade resolves a controller for an external target, calls its capability check, and verifies permitted input tokens. Unknown targets return a denied result with empty token lists.

`can_call` uses a typed action; `can_call_fn` uses a function symbol. Each returns `(allowed, tokens_in, tokens_out)`. `validate_tokens_in` checks a supplied list against Registry. Admin can change Registry and upgrade WASM.

The facade remains available as a policy interface. AccountManager's current `exec` implementation optimizes the transaction budget by reading `Registry.get_exec_gate` and calling the controller directly, so an architecture diagram must not require the facade in every execution.

## Function signatures

These signatures are copied from the reviewed Rust implementation. `env` is supplied by Soroban and is not a transaction argument. `Result` errors and panics must be handled by the caller; simulation does not guarantee later execution. Public methods include privileged and internal-contract callbacks, not just user entrypoints.

### \_\_constructor

```rust theme={null}
pub fn __constructor(env: Env, admin: Address, registry: Address)
```

### can\_call

```rust theme={null}
pub fn can_call(
        env: &Env,
        target: Address,
        action: ExternalAction,
        tokens: Vec<Address>,
    ) -> (bool, Vec<Address>, Vec<Address>)
```

### can\_call\_fn

```rust theme={null}
pub fn can_call_fn(
        env: &Env,
        target: Address,
        func: soroban_sdk::Symbol,
        tokens: Vec<Address>,
    ) -> (bool, Vec<Address>, Vec<Address>)
```

### validate\_tokens\_in

```rust theme={null}
pub fn validate_tokens_in(env: &Env, tokens_in: Vec<Address>) -> bool
```

### get\_registry

```rust theme={null}
pub fn get_registry(env: &Env) -> Address
```

### set\_registry

```rust theme={null}
pub fn set_registry(env: &Env, new_registry: Address)
```

### upgrade

```rust theme={null}
pub fn upgrade(env: &Env, new_wasm_hash: BytesN<32>)
```

## Source reference

* `Protocol_V1_Soroban_testnet/contracts/ControllerFacadeContract/src/facade.rs`