feat: create initial external-proofs ExEx crate

Cargo.toml

@@ -49,6 +49,7 @@ members = [
     "crates/exex/exex/",
     "crates/exex/test-utils/",
     "crates/exex/types/",
+    "crates/exex/external-proofs/",
     "crates/metrics/",
     "crates/net/banlist/",
     "crates/net/discv4/",

crates/exex/external-proofs/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "external-proofs"
+version = "0.1.0"
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+homepage.workspace = true
+repository.workspace = true
+description = "ExEx to save and serve trie nodes to make proofs faster."
+
+[lints]
+workspace = true
+
+[dependencies]
+reth-exex.workspace = true
+
+# reth
+reth-provider.workspace = true
+reth-node-types.workspace = true
+reth-node-api.workspace = true
+
+# misc
+eyre.workspace = true
+futures-util.workspace = true

crates/exex/external-proofs/src/lib.rs

@@ -0,0 +1,48 @@
+//! External Proofs ExEx - processes blocks and tracks state changes
+
+use futures_util::TryStreamExt;
+use reth_node_api::{FullNodeComponents, NodePrimitives};
+use reth_node_types::NodeTypes;
+use reth_provider::StateReader;
+
+use reth_exex::{ExExContext, ExExEvent};
+
+/// Saves and serves trie nodes to make proofs faster. This handles the process of
+/// saving the current state, new blocks as they're added, and serving proof RPCs
+/// based on the saved data.
+#[derive(Debug)]
+pub struct ExternalProofExEx<Node>
+where
+    Node: FullNodeComponents,
+    Node::Provider: StateReader,
+{
+    ctx: ExExContext<Node>,
+}
+
+impl<Node, Primitives> ExternalProofExEx<Node>
+where
+    Node: FullNodeComponents<Types: NodeTypes<Primitives = Primitives>>,
+    Primitives: NodePrimitives,
+{
+    /// Create a new `ExternalProofExEx` instance
+    pub const fn new(ctx: ExExContext<Node>) -> Self {
+        Self { ctx }
+    }
+
+    /// Main execution loop for the ExEx
+    pub async fn run(mut self) -> eyre::Result<()> {
+        while let Some(notification) = self.ctx.notifications.try_next().await? {
+            // match &notification {
+            //     _ => {}
+            // };
+
+            if let Some(committed_chain) = notification.committed_chain() {
+                self.ctx
+                    .events
+                    .send(ExExEvent::FinishedHeight(committed_chain.tip().num_hash()))?;
+            }
+        }
+
+        Ok(())
+    }
+}