Add contracts to asset folder and update Deployment Method and `Ref…

…erence Implementation` sections

ERCS/erc-5564.md

@@ -259,9 +259,13 @@ The recipient's address and the `viewTag` MUST be included in the announcement e
 
 This ERC is fully backward compatible.
 
+### Deployment Method
+
+The `ERC5564Announcer` contract is deployed at `0x55649E01B5Df198D18D95b5cc5051630cfD45564` using `CREATE2` via the deterministic deployer at `0x4e59b44847b379578588920ca78fbf26c0b4956c` with a salt of `0xd0103a290d760f027c9ca72675f5121d725397fb2f618f05b6c44958b25b4447`.
+
 ## Reference Implementation
 
-You can find the implementation of the ERC above in the Specification section.
+You can find the implementation of the `ERC5564Announcer` contract [here](../assets/eip-5564/contracts/ERC5564Announcer.sol) and the interface `IERC5564Announcer.sol` [here](../assets/eip-5564/contracts/interfaces/IERC5564Announcer.sol).
 
 ## Security Considerations
 

assets/erc-5564/contracts/ERC5564Announcer.sol

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: CC0-1.0
+pragma solidity 0.8.23;
+
+/// @notice `ERC5564Announcer` contract to emit an `Announcement` event to broadcast information
+/// about a transaction involving a stealth address. See
+/// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) to learn more.
+contract ERC5564Announcer {
+  /// @notice Emitted when something is sent to a stealth address.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthAddress The computed stealth address for the recipient.
+  /// @param caller The caller of the `announce` function that emitted this event.
+  /// @param ephemeralPubKey Ephemeral public key used by the sender to derive the `stealthAddress`.
+  /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
+  /// @dev The remaining metadata can be used by the senders however they like. See
+  /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
+  /// this metadata.
+  event Announcement(
+    uint256 indexed schemeId,
+    address indexed stealthAddress,
+    address indexed caller,
+    bytes ephemeralPubKey,
+    bytes metadata
+  );
+
+  /// @notice Called by integrators to emit an `Announcement` event.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthAddress The computed stealth address for the recipient.
+  /// @param ephemeralPubKey Ephemeral public key used by the sender.
+  /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
+  /// @dev The remaining metadata can be used by the senders however they like. See
+  /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
+  /// this metadata.
+  function announce(
+    uint256 schemeId,
+    address stealthAddress,
+    bytes memory ephemeralPubKey,
+    bytes memory metadata
+  ) external {
+    emit Announcement(schemeId, stealthAddress, msg.sender, ephemeralPubKey, metadata);
+  }
+}

assets/erc-5564/contracts/interfaces/IERC5564Announcer.sol

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: CC0-1.0
+pragma solidity 0.8.23;
+
+/// @notice Interface for calling the `ERC5564Announcer` contract, which emits an `Announcement`
+/// event to broadcast information about a transaction involving a stealth address. See
+/// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) to learn more.
+interface IERC5564Announcer {
+  /// @notice Emitted when something is sent to a stealth address.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthAddress The computed stealth address for the recipient.
+  /// @param caller The caller of the `announce` function that emitted this event.
+  /// @param ephemeralPubKey Ephemeral public key used by the sender to derive the `stealthAddress`.
+  /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
+  /// @dev The remaining metadata can be used by the senders however they like. See
+  /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
+  /// this metadata.
+  event Announcement(
+    uint256 indexed schemeId,
+    address indexed stealthAddress,
+    address indexed caller,
+    bytes ephemeralPubKey,
+    bytes metadata
+  );
+
+  /// @notice Called by integrators to emit an `Announcement` event.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthAddress The computed stealth address for the recipient.
+  /// @param ephemeralPubKey Ephemeral public key used by the sender.
+  /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
+  /// @dev The remaining metadata can be used by the senders however they like. See
+  /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
+  /// this metadata.
+  function announce(
+    uint256 schemeId,
+    address stealthAddress,
+    bytes memory ephemeralPubKey,
+    bytes memory metadata
+  ) external;
+}