From e9abc14b4ce2b03935695b177d87ac3667b32444 Mon Sep 17 00:00:00 2001
From: Enigbe <ochekliyeenigbe@gmail.com>
Date: Tue, 24 Feb 2026 13:03:33 +0100
Subject: [PATCH] Add LdkServer to manage comms with an instance of ldk-server
 (daemon)

Explores the addition of a client to manage communication
with an instance of an ldk-server.

We realize early the disparity between the local node
information APIs exposed by LDK, relative to LND and CLN,
and need to add feature support on ldk-node/server
to permit the retrieval of the running node's network and features.

These are necessary for sim-ln's validation logic as:
- network ensures all nodes run on the same network, and also do
not run on the mainnet
- features ensure that keysend support is enabled
---
 simln-lib/Cargo.toml               |  1 +
 simln-lib/src/ldk.rs               | 90 ++++++++++++++++++++++++++++++
 simln-lib/src/lib.rs               |  1 +
 simln-lib/tests/ldk_integration.rs | 14 +++++
 4 files changed, 106 insertions(+)
 create mode 100644 simln-lib/src/ldk.rs
 create mode 100644 simln-lib/tests/ldk_integration.rs

diff --git a/simln-lib/Cargo.toml b/simln-lib/Cargo.toml
index 39d2f5ca..2c9faafe 100755
--- a/simln-lib/Cargo.toml
+++ b/simln-lib/Cargo.toml
@@ -33,6 +33,7 @@ rand_distr = "0.4.3"
 rand_chacha = "0.3.1"
 reqwest = { version = "0.12", features = ["json", "multipart"] }
 tokio-util = { version = "0.7.13", features = ["rt"] }
+ldk-server-client = { git = "https://github.com/enigbe/ldk-server", rev = "refs/pull/1/head", package = "ldk-server-client"}
 
 [dev-dependencies]
 ntest = "0.9.0"
diff --git a/simln-lib/src/ldk.rs b/simln-lib/src/ldk.rs
new file mode 100644
index 00000000..36ca16b8
--- /dev/null
+++ b/simln-lib/src/ldk.rs
@@ -0,0 +1,90 @@
+use std::str::FromStr;
+
+use async_trait::async_trait;
+use bitcoin::Network;
+use ldk_server_client::client::LdkServerClient;
+use lightning::ln::features::NodeFeatures;
+
+use crate::{LightningError, LightningNode, NodeInfo};
+
+pub struct LdkServerConnection {
+    pub base_url: String,
+    pub api_key: String,
+    pub server_cert_pem: Vec<u8>,
+}
+
+pub struct LdkServer {
+    client: LdkServerClient,
+    info: NodeInfo,
+    network: Network,
+}
+
+impl LdkServer {
+    /// Creates a new instance that connects to a running `ldk-server` node (daemon).
+    pub async fn new(connection: LdkServerConnection) -> Result<Self, LightningError> {
+        let client = LdkServerClient::new(base_url, api_key, server_cert_pem)
+            .map_err(|e| LightningError::ConnectionError(e))?;
+
+        let node_info_res = client
+            .get_node_info(node_info_req)
+            .await
+            .map_err(|e| LightningError::GetNodeInfoError(e.to_string()))?;
+
+        let network = Network::from_str(node_info_res.network.as_str())
+            .map_err(|e| LightningError::GetNodeInfoError(e.to_string()))?;
+
+        let info = NodeInfo {
+            pubkey: node_info_res.node_id.into(),
+            alias: node_info_res.node_alias().to_string(),
+            features: match node_info_res.features {
+                Some(features) => NodeFeatures::from_be_bytes(features.node.to_vec()),
+                None => NodeFeatures::empty(),
+            },
+        };
+
+        Ok(Self {
+            client,
+            info,
+            network,
+        })
+    }
+}
+
+#[async_trait]
+impl LightningNode for LdkServer {
+    fn get_info(&self) -> &NodeInfo {
+        todo!()
+    }
+
+    fn get_network(&self) -> Network {
+        todo!()
+    }
+
+    async fn send_payment(
+        &self,
+        dest: PublicKey,
+        amount_msat: u64,
+    ) -> Result<PaymentHash, LightningError> {
+        todo!()
+    }
+
+    async fn track_payment(
+        &self,
+        hash: &PaymentHash,
+        shutdown: Listener,
+    ) -> Result<PaymentResult, LightningError> {
+        todo!()
+    }
+
+    async fn get_node_info(&self, node_id: &PublicKey) -> Result<NodeInfo, LightningError> {
+        todo!()
+    }
+
+    async fn channel_capacities(&self) -> Result<u64, LightningError> {
+        todo!()
+    }
+
+    async fn get_graph(&self) -> Result<Graph, LightningError> {
+        todo!()
+    }
+}
diff --git a/simln-lib/src/lib.rs b/simln-lib/src/lib.rs
index a1b5fe0e..23988abb 100755
--- a/simln-lib/src/lib.rs
+++ b/simln-lib/src/lib.rs
@@ -36,6 +36,7 @@ pub mod clock;
 mod defined_activity;
 pub mod eclair;
 pub mod latency_interceptor;
+pub mod ldk;
 pub mod lnd;
 mod random_activity;
 pub mod serializers;
diff --git a/simln-lib/tests/ldk_integration.rs b/simln-lib/tests/ldk_integration.rs
new file mode 100644
index 00000000..f8a3f60c
--- /dev/null
+++ b/simln-lib/tests/ldk_integration.rs
@@ -0,0 +1,14 @@
+use simln_lib::ldk::{LdkServer, LdkServerConnection};
+
+#[test]
+async fn connect_successfully_to_ldkserver() {
+    let conn = LdkServerConnection {
+        base_url: "127.0.0.1:3002".to_string(),
+        api_key: todo!(),
+        server_cert_pem: todo!(),
+    };
+    let client = LdkServer::new(conn)
+        .await
+        .expect("Failed to connect to LDK server.");
+    todo!()
+}