Updates related to the fact we'll have an autorelayer on mainnet

components/AutorelayCallout.tsx

@@ -0,0 +1,27 @@
+/**
+ * The AutorelayCallout function renders a callout component with a message about autorelays
+ * 
+ * @param {Props} props - Expected to be empty, ignored.
+ * @returns {ReactElement} The AutorelayCallout component, a callout that explains about autorelays.
+ */
+import type { ReactElement } from 'react';
+import { useState } from 'react';
+
+interface Props {
+  context?: string;
+}
+export function AutorelayCallout({ context }: Props): ReactElement {
+  return (
+    <div
+      className="custom-callouts nx-w-full nx-mt-6 nx-flex nx-justify-center nx-items-center nx-bg-white dark:nx-bg-black"
+    >
+      <div className="nx-w-full  nx-px-4 nx-text-center nx-font-medium nx-text-sm nx-text-left">
+          <div className="nx-text-left">
+            Normally we expect Superchain blockchains to run an autorelayer and relay your messages automatically.
+            However, for performance reasons or reliability, you might decide to subnmit the executing message manually.
+            This section shows how to do that.
+          </div>
+      </div>
+    </div>
+  );
+}

pages/stack/interop/message-passing.mdx

@@ -69,7 +69,7 @@ sequenceDiagram
 ```mermaid
 
 sequenceDiagram
-    participant app as Application
+    participant app as Autorelayer
     box rgba(0,0,0,0.1) Source Chain
       participant log as Event Log
     end    
@@ -88,7 +88,7 @@ sequenceDiagram
 
 1.  Before the executing message is processed, the log event of the initiating message has to get to `op-supervisor` on the destination chain.
 
-2.  The application (or a contract calling on the application's behalf) calls [`L2ToL2CrossDomainMessenger.SendMessage.relayMessage`](https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts-bedrock/src/L2/L2ToL2CrossDomainMessenger.sol#L156-L216).
+2.  The autorelayer, the application, or a contract calling on the application's behalf calls [`L2ToL2CrossDomainMessenger.SendMessage.relayMessage`](https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts-bedrock/src/L2/L2ToL2CrossDomainMessenger.sol#L156-L216).
     This call includes the message that was sent (`_sendMessage`), as well as the [fields required to find that message (`_id`)](https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts-bedrock/interfaces/L2/ICrossL2Inbox.sol#L4-L10).
 
 3.  The `L2ToL2CrossDomainMessenger` uses `CrossL2Inbox` to verify the message was sent from the source.
@@ -107,10 +107,9 @@ sequenceDiagram
 ## Next steps
 
 *   Build a [revolutionary app](/app-developers/get-started) that uses multiple blockchains within the Superchain
+*   Actually [pass messages between blockchains](/stack/interop/tutorials/message-passing).
 *   Deploy a [SuperchainERC20](/stack/interop/tutorials/deploy-superchain-erc20) to the Superchain
 *   Practice how to use [Superchain interop message passing](/stack/interop/message-passing)
 *   Read how [messages get from one blockchain to another (`CrossL2Inbox`)](explainer#how-messages-get-from-one-chain-to-the-other).
 *   Try [Supersim](tools/supersim) for testing cross-chain messages locally.
 *   Learn about [manually relaying messages](/stack/interop/tutorials/relay-messages-viem)
-
-{/*  After the tutorial for L2ToL2CrossDomainMessenger is written, need to add a link here */}

pages/stack/interop/superchain-weth.mdx

@@ -82,13 +82,13 @@ sequenceDiagram
 
 4.  An off-chain entity submits a transaction to execute the message.
     Any address can submit this transaction, but it must have ETH on the destination chain.
-    Typically, a relayer submits the transaction, since the user does not yet have ETH on the destination chain.
+    Typically this would be thge chain's autorelayer.
 
 5.  `L2ToL2CrossDomainMessenger` on the destination chain calls `SuperchainWETH` with the following details:
 
-*   Source of the ETH
-*   Destination address
-*   Amount of ETH
+    *   Source of the ETH
+    *   Destination address
+    *   Amount of ETH
 
     `SuperchainWETH` performs several sanity checks:
 

pages/stack/interop/tutorials/message-passing.mdx

@@ -7,6 +7,7 @@ description: Learn to implement cross-chain communication in the Superchain by b
 import { Callout } from 'nextra/components'
 import { Steps } from 'nextra/components'
 import { InteropCallout } from '@/components/WipCallout'
+import { AutorelayCallout } from '@/components/AutorelayCallout'
 
 <InteropCallout />
 
@@ -362,6 +363,8 @@ In this section we change `Greeter.sol` to emit a separate event in it receives
 
 ## Implement manual message relaying
 
+<AutorelayCallout />
+
 So far we relied on `--interop.autorelay` to send the executing messages to chain B.
 But we only have it because we're using a development system.
 In production we will not have this, we need to create our own executing messages.