diff --git a/Cargo.lock b/Cargo.lock
index cd9ab02eeb..46aefe4262 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4655,6 +4655,7 @@ dependencies = [
  "postgres",
  "rand",
  "regex",
+ "safekeeper",
  "serde",
  "thiserror",
  "utils",
diff --git a/Cargo.toml b/Cargo.toml
index 188f663971..02777f2240 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -138,6 +138,7 @@ postgres_ffi = { version = "0.1", path = "./libs/postgres_ffi/" }
 pq_proto = { version = "0.1", path = "./libs/pq_proto/" }
 remote_storage = { version = "0.1", path = "./libs/remote_storage/" }
 safekeeper_api = { version = "0.1", path = "./libs/safekeeper_api" }
+safekeeper = { path = "./safekeeper/" }
 storage_broker = { version = "0.1", path = "./storage_broker/" } # Note: main broker code is inside the binary crate, so linking with the library shouldn't be heavy.
 tenant_size_model = { version = "0.1", path = "./libs/tenant_size_model/" }
 tracing-utils = { version = "0.1", path = "./libs/tracing-utils/" }
diff --git a/libs/walproposer/.gitignore b/libs/walproposer/.gitignore
index 9eca6c88cf..8800186e5f 100644
--- a/libs/walproposer/.gitignore
+++ b/libs/walproposer/.gitignore
@@ -1,2 +1,3 @@
 *.a
 *.o
+*.tmp
diff --git a/libs/walproposer/Cargo.toml b/libs/walproposer/Cargo.toml
index 62e8cb6c64..9fcd252386 100644
--- a/libs/walproposer/Cargo.toml
+++ b/libs/walproposer/Cargo.toml
@@ -18,6 +18,7 @@ memoffset.workspace = true
 thiserror.workspace = true
 serde.workspace = true
 utils.workspace = true
+safekeeper.workspace = true
 
 workspace_hack.workspace = true
 
diff --git a/libs/walproposer/bindgen_deps.h b/libs/walproposer/bindgen_deps.h
index 8d5c956bca..a10ca230e4 100644
--- a/libs/walproposer/bindgen_deps.h
+++ b/libs/walproposer/bindgen_deps.h
@@ -8,3 +8,4 @@
 // #include "walproposer.h"
 
 int TestFunc(int a, int b);
+void RunClientC();
diff --git a/libs/walproposer/build.rs b/libs/walproposer/build.rs
index 794ea5ad5e..65f3db460f 100644
--- a/libs/walproposer/build.rs
+++ b/libs/walproposer/build.rs
@@ -125,6 +125,7 @@ fn main() -> anyhow::Result<()> {
         // included header files changed.
         .parse_callbacks(Box::new(CargoCallbacks))
         .allowlist_function("TestFunc")
+        .allowlist_function("RunClientC")
         // .allowlist_function("WalProposerRust")
         // .clang_arg(format!("-I{inc_server_path}"))
         // .clang_arg(format!("-I{inc_pgxn_path}"))
diff --git a/libs/walproposer/rust_bindings.h b/libs/walproposer/rust_bindings.h
index 358731c5cf..2f8611a03e 100644
--- a/libs/walproposer/rust_bindings.h
+++ b/libs/walproposer/rust_bindings.h
@@ -4,3 +4,5 @@
 #include <stdlib.h>
 
 void rust_function(uint32_t a);
+
+void sim_sleep(uint64_t ms);
diff --git a/libs/walproposer/src/lib.rs b/libs/walproposer/src/lib.rs
index 2815de1e65..cb900005a3 100644
--- a/libs/walproposer/src/lib.rs
+++ b/libs/walproposer/src/lib.rs
@@ -6,23 +6,16 @@ pub mod bindings {
     include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 }
 
-pub use bindings::{TestFunc};
-
-use std::cell::RefCell;
-
-thread_local! {
-    pub static TMP_TEST: RefCell<Vec<u32>> = RefCell::new(vec![]);
-}
-
 #[no_mangle]
 pub extern "C" fn rust_function(a: u32) {
     println!("Hello from Rust!");
     println!("a: {}", a);
-    TMP_TEST.with(|f| {
-        f.borrow_mut().push(a);
-        println!("TMP_TEST: {:?}", f.borrow());
-    });
 }
 
+pub mod sim;
+
 #[cfg(test)]
 mod test;
+
+#[cfg(test)]
+pub mod simtest;
diff --git a/libs/walproposer/src/sim.rs b/libs/walproposer/src/sim.rs
new file mode 100644
index 0000000000..be5eacec33
--- /dev/null
+++ b/libs/walproposer/src/sim.rs
@@ -0,0 +1,27 @@
+use std::cell::RefCell;
+
+use safekeeper::simlib::node_os::NodeOs;
+
+thread_local! {
+    pub static CURRENT_NODE_OS: RefCell<Option<NodeOs>> = RefCell::new(None);
+}
+
+/// Get the current node os.
+fn os() -> NodeOs {
+    CURRENT_NODE_OS.with(|cell| {
+        cell.borrow().clone().expect("no node os set")
+    })
+}
+
+/// Should be called before calling any of the C functions.
+pub fn c_attach_node_os(os: NodeOs) {
+    CURRENT_NODE_OS.with(|cell| {
+        *cell.borrow_mut() = Some(os);
+    });
+}
+
+#[no_mangle]
+pub extern "C" fn sim_sleep(ms: u64) {
+    println!("got a call to sleep for {} ms", ms);
+    os().sleep(ms);
+}
diff --git a/libs/walproposer/src/simtest/mod.rs b/libs/walproposer/src/simtest/mod.rs
new file mode 100644
index 0000000000..c9c0f39aef
--- /dev/null
+++ b/libs/walproposer/src/simtest/mod.rs
@@ -0,0 +1,41 @@
+use std::sync::Arc;
+
+use safekeeper::simlib::{network::{NetworkOptions, Delay}, world::World};
+
+use crate::{bindings::RunClientC, sim::c_attach_node_os};
+
+#[test]
+fn run_rust_c_test() {
+    let delay = Delay {
+        min: 1,
+        max: 60,
+        fail_prob: 0.4,
+    };
+
+    let network = NetworkOptions {
+        timeout: Some(50),
+        connect_delay: delay.clone(),
+        send_delay: delay.clone(),
+    };
+    let seed = 1337;
+
+    start_simulation_2(seed, network.clone(), 1_000_000);
+}
+
+fn start_simulation_2(seed: u64, network: NetworkOptions, time_limit: u64) {
+    let network = Arc::new(network);
+    let world = Arc::new(World::new(seed, network));
+    world.register_world();
+
+    let client_node = world.new_node();
+    client_node.launch(move |os| {
+        c_attach_node_os(os);
+        unsafe { RunClientC() }
+    });
+
+    world.await_all();
+
+    while world.step() && world.now() < time_limit {
+        println!("made a step");
+    }
+}
diff --git a/libs/walproposer/src/test.rs b/libs/walproposer/src/test.rs
index bda40356c1..9e70c928d8 100644
--- a/libs/walproposer/src/test.rs
+++ b/libs/walproposer/src/test.rs
@@ -1,8 +1,12 @@
-use crate::{TestFunc, TMP_TEST};
+use crate::bindings::{TestFunc, RunClientC};
 
 #[test]
-fn run_test() {
+fn test_rust_c_calls() {
     let res = unsafe { TestFunc(1, 2) };
-    // unsafe { WalProposerRust(); }
     println!("res: {}", res);
 }
+
+#[test]
+fn test_sim_bindings() {
+    unsafe { RunClientC(); }
+}
diff --git a/libs/walproposer/test.c b/libs/walproposer/test.c
index 20086604de..61f8c7945b 100644
--- a/libs/walproposer/test.c
+++ b/libs/walproposer/test.c
@@ -16,3 +16,14 @@ int TestFunc(int a, int b) {
     printf("After rust_function\n");
     return a + b;
 }
+
+// This is a quick experiment with rewriting existing Rust code in C.
+void RunClientC() {
+    MemoryContextInit();
+
+    elog(LOG, "started client");
+
+    for (int i = 0; i < 10; i++) {
+        sim_sleep(100);
+    }
+}
diff --git a/safekeeper/src/simlib/node_os.rs b/safekeeper/src/simlib/node_os.rs
index 3344e2bb39..b582aa0c7e 100644
--- a/safekeeper/src/simlib/node_os.rs
+++ b/safekeeper/src/simlib/node_os.rs
@@ -10,6 +10,7 @@ use super::{
 };
 
 /// Abstraction with all functions (aka syscalls) available to the node.
+#[derive(Clone)]
 pub struct NodeOs {
     world: Arc<World>,
     internal: Arc<Node>,
diff --git a/safekeeper/src/simtest/mod.rs b/safekeeper/src/simtest/mod.rs
index 6ec9f9157e..22e8d5e2af 100644
--- a/safekeeper/src/simtest/mod.rs
+++ b/safekeeper/src/simtest/mod.rs
@@ -14,7 +14,7 @@ use crate::{
 };
 
 #[test]
-fn run_test() {
+fn run_pure_rust_test() {
     let delay = Delay {
         min: 1,
         max: 60,