> For the complete documentation index, see [llms.txt](https://docs.orbitcdp.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.orbitcdp.finance/technical-documentation/bridge-oracle.md).

# Bridge Oracle

The Bridge Oracle contract provides reliable price feeds for the Orbit Protocol by connecting different assets to their reference values. It serves as a critical price discovery mechanism that enables accurate asset valuations within the protocol.

## Price Feed Management

The Bridge Oracle manages price feeds by mapping assets to their reference counterparts and retrieving price data from specialized oracle sources.

### Asset Mapping

Assets are mapped to their reference assets using the `add_asset()` function:

```rust
fn add_asset(e: Env, asset: Asset, to: Asset)
```

This function:

* Creates a mapping between the source asset and its reference asset
* Can only be called by the admin
* Allows bridging between Stellar assets and external assets
* Emits an event recording the mapping

### Price Retrieval

The Bridge Oracle provides price data through the `lastprice()` function:

```rust
fn lastprice(env: Env, asset: Asset) -> Option<PriceData>
```

When retrieving prices:

1. The contract looks up the reference asset for the requested asset
2. Based on the type of reference asset, it routes the request to the appropriate oracle:
   * For Stellar assets, it queries the Stellar oracle
   * For USD, it returns a fixed value of 1 with the current timestamp
   * For other external assets, it queries the external oracle
3. Returns the price data if available, or None if not found

### Decimal Precision

The contract provides information about the decimal precision used by the Stellar oracle:

```rust
fn decimals(env: Env) -> u32
```

This function relays the decimal precision information from the underlying Stellar oracle.

## Administration

The Bridge Oracle provides administrative functions to manage protocol configuration.

### Setting Oracle Sources

The data sources for the Bridge Oracle can be updated using:

```rust
fn set_oracles(e: Env, stellar_oracle: Address, other_oracle: Address)
```

This function:

* Updates the addresses for both the Stellar and external oracles
* Can only be called by the admin
* Emits an event recording the change

### Setting the Admin

The admin address can be updated by the current admin:

```rust
fn set_admin(e: Env, new_admin: Address)
```

This function updates the admin address and emits an event recording the change.

### Contract Upgrades

The Bridge Oracle supports upgradability through Soroban's native upgrade mechanism:

```rust
fn upgrade(e: Env, new_wasm_hash: BytesN<32>)
```

This function allows the admin to upgrade the contract to a new implementation while preserving all contract storage.

## Contract Initialization

The Bridge Oracle is initialized with three key parameters:

```rust
fn __constructor(e: Env, admin: Address, stellar_oracle: Address, other_oracle: Address)
```

During initialization:

* The admin address is set (the DAO contract)
* The Stellar oracle address is configured
* The external oracle address is configured
* An initialization event is emitted

All future administrative operations will require authorization from this admin address.

## Events

The Bridge Oracle emits events for all major operations:

* `init`: Contract initialization with admin and oracle addresses
* `add_asset`: Creation of a new asset mapping
* `set_oracles`: Update to oracle sources
* `set_admin`: Admin address update