diff --git a/src/agent/coverage/src/source.rs b/src/agent/coverage/src/source.rs
index 33067e6cc6..10c6cb2342 100644
--- a/src/agent/coverage/src/source.rs
+++ b/src/agent/coverage/src/source.rs
@@ -15,12 +15,12 @@ use crate::binary::BinaryCoverage;
 
 pub use crate::binary::Count;
 
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
 pub struct SourceCoverage {
     pub files: BTreeMap<FilePath, FileCoverage>,
 }
 
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
 pub struct FileCoverage {
     pub lines: BTreeMap<Line, Count>,
 }
diff --git a/src/agent/onefuzz-agent/src/agent.rs b/src/agent/onefuzz-agent/src/agent.rs
index d26ecb732a..17059332ae 100644
--- a/src/agent/onefuzz-agent/src/agent.rs
+++ b/src/agent/onefuzz-agent/src/agent.rs
@@ -12,7 +12,7 @@ use crate::reboot::*;
 use crate::scheduler::*;
 use crate::setup::*;
 use crate::work::IWorkQueue;
-use crate::worker::IWorkerRunner;
+use crate::worker::{IWorkerRunner, WorkerEvent};
 
 const PENDING_COMMANDS_DELAY: time::Duration = time::Duration::from_secs(10);
 const BUSY_DELAY: time::Duration = time::Duration::from_secs(1);
@@ -62,7 +62,7 @@ impl Agent {
         }
     }
 
-    pub async fn run(&mut self) -> Result<()> {
+    pub async fn run(self) -> Result<()> {
         let mut instant = time::Instant::now();
 
         // Tell the service that the agent has started.
@@ -78,42 +78,39 @@ impl Agent {
             let event = StateUpdateEvent::Init.into();
             self.coordinator.emit_event(event).await?;
         }
-
-        loop {
-            self.heartbeat.alive();
+        let mut state = self;
+        let mut done = false;
+        while !done {
+            state.heartbeat.alive();
             if instant.elapsed() >= PENDING_COMMANDS_DELAY {
-                self.execute_pending_commands().await?;
+                state = state.execute_pending_commands().await?;
                 instant = time::Instant::now();
             }
 
-            let done = self.update().await?;
-
-            if done {
-                debug!("agent done, exiting loop");
-                break;
-            }
+            (state, done) = state.update().await?;
         }
 
+        info!("agent done, exiting loop");
         Ok(())
     }
 
-    async fn update(&mut self) -> Result<bool> {
+    async fn update(mut self) -> Result<(Self, bool)> {
         let last = self.scheduler.take().ok_or_else(scheduler_error)?;
         let previous_state = NodeState::from(&last);
         let (next, done) = match last {
-            Scheduler::Free(s) => (self.free(s).await?, false),
-            Scheduler::SettingUp(s) => (self.setting_up(s).await?, false),
-            Scheduler::PendingReboot(s) => (self.pending_reboot(s).await?, false),
-            Scheduler::Ready(s) => (self.ready(s).await?, false),
-            Scheduler::Busy(s) => (self.busy(s).await?, false),
-            Scheduler::Done(s) => (self.done(s).await?, true),
+            Scheduler::Free(s) => (self.free(s, previous_state).await?, false),
+            Scheduler::SettingUp(s) => (self.setting_up(s, previous_state).await?, false),
+            Scheduler::PendingReboot(s) => (self.pending_reboot(s, previous_state).await?, false),
+            Scheduler::Ready(s) => (self.ready(s, previous_state).await?, false),
+            Scheduler::Busy(s) => (self.busy(s, previous_state).await?, false),
+            //todo: introduce  a new prameter to allow the agent to restart after this point
+            Scheduler::Done(s) => (self.done(s, previous_state).await?, true),
         };
-        self.previous_state = previous_state;
-        self.scheduler = Some(next);
-        Ok(done)
+
+        Ok((next, done))
     }
 
-    async fn emit_state_update_if_changed(&mut self, event: StateUpdateEvent) -> Result<()> {
+    async fn emit_state_update_if_changed(&self, event: StateUpdateEvent) -> Result<()> {
         match (&event, self.previous_state) {
             (StateUpdateEvent::Free, NodeState::Free)
             | (StateUpdateEvent::Busy, NodeState::Busy)
@@ -129,7 +126,7 @@ impl Agent {
         Ok(())
     }
 
-    async fn free(&mut self, state: State<Free>) -> Result<Scheduler> {
+    async fn free(mut self, state: State<Free>, previous: NodeState) -> Result<Self> {
         self.emit_state_update_if_changed(StateUpdateEvent::Free)
             .await?;
 
@@ -190,7 +187,7 @@ impl Agent {
                     // Otherwise, the work was not stopped, but we still should not execute it. This is likely
                     // our because agent version is out of date. Do nothing, so another node can see the work.
                     // The service will eventually send us a stop command and reimage our node, if appropriate.
-                    debug!(
+                    info!(
                         "not scheduling active work set, not dropping: {:?}",
                         msg.work_set
                     );
@@ -205,11 +202,15 @@ impl Agent {
             state.into()
         };
 
-        Ok(next)
+        Ok(Self {
+            previous_state: previous,
+            scheduler: Some(next),
+            ..self
+        })
     }
 
-    async fn setting_up(&mut self, state: State<SettingUp>) -> Result<Scheduler> {
-        debug!("agent setting up");
+    async fn setting_up(mut self, state: State<SettingUp>, previous: NodeState) -> Result<Self> {
+        info!("agent setting up");
 
         let tasks = state.work_set().task_ids();
         self.emit_state_update_if_changed(StateUpdateEvent::SettingUp { tasks })
@@ -221,11 +222,19 @@ impl Agent {
             SetupDone::Done(s) => s.into(),
         };
 
-        Ok(scheduler)
+        Ok(Self {
+            previous_state: previous,
+            scheduler: Some(scheduler),
+            ..self
+        })
     }
 
-    async fn pending_reboot(&mut self, state: State<PendingReboot>) -> Result<Scheduler> {
-        debug!("agent pending reboot");
+    async fn pending_reboot(
+        self,
+        state: State<PendingReboot>,
+        _previous: NodeState,
+    ) -> Result<Self> {
+        info!("agent pending reboot");
         self.emit_state_update_if_changed(StateUpdateEvent::Rebooting)
             .await?;
 
@@ -236,14 +245,18 @@ impl Agent {
         unreachable!()
     }
 
-    async fn ready(&mut self, state: State<Ready>) -> Result<Scheduler> {
-        debug!("agent ready");
+    async fn ready(self, state: State<Ready>, previous: NodeState) -> Result<Self> {
+        info!("agent ready");
         self.emit_state_update_if_changed(StateUpdateEvent::Ready)
             .await?;
-        Ok(state.run().await?.into())
+        Ok(Self {
+            previous_state: previous,
+            scheduler: Some(state.run().await?.into()),
+            ..self
+        })
     }
 
-    async fn busy(&mut self, state: State<Busy>) -> Result<Scheduler> {
+    async fn busy(mut self, state: State<Busy>, previous: NodeState) -> Result<Self> {
         self.emit_state_update_if_changed(StateUpdateEvent::Busy)
             .await?;
 
@@ -255,7 +268,7 @@ impl Agent {
         // that is done, this sleep should be removed.
         time::sleep(BUSY_DELAY).await;
 
-        let mut events = vec![];
+        let mut events: Vec<WorkerEvent> = vec![];
         let updated = state
             .update(&mut events, self.worker_runner.as_mut())
             .await?;
@@ -264,11 +277,15 @@ impl Agent {
             self.coordinator.emit_event(event.into()).await?;
         }
 
-        Ok(updated.into())
+        Ok(Self {
+            previous_state: previous,
+            scheduler: Some(updated.into()),
+            ..self
+        })
     }
 
-    async fn done(&mut self, state: State<Done>) -> Result<Scheduler> {
-        debug!("agent done");
+    async fn done(self, state: State<Done>, previous: NodeState) -> Result<Self> {
+        info!("agent done");
         set_done_lock(self.machine_id).await?;
 
         let event = match state.cause() {
@@ -287,23 +304,41 @@ impl Agent {
 
         self.emit_state_update_if_changed(event).await?;
         // `Done` is a final state.
-        Ok(state.into())
+        Ok(Self {
+            previous_state: previous,
+            scheduler: Some(state.into()),
+            ..self
+        })
     }
 
-    async fn execute_pending_commands(&mut self) -> Result<()> {
+    async fn execute_pending_commands(mut self) -> Result<Self> {
         let result = self.coordinator.poll_commands().await;
 
         match &result {
-            Ok(None) => {}
+            Ok(None) => Ok(Self {
+                last_poll_command: result,
+                ..self
+            }),
             Ok(Some(cmd)) => {
                 info!("agent received node command: {:?}", cmd);
                 let managed = self.managed;
-                self.scheduler()?.execute_command(cmd, managed).await?;
+                let scheduler = self.scheduler.take().ok_or_else(scheduler_error)?;
+                let new_scheduler = scheduler.execute_command(cmd.clone(), managed).await?;
+
+                Ok(Self {
+                    last_poll_command: result,
+                    scheduler: Some(new_scheduler),
+                    ..self
+                })
             }
             Err(PollCommandError::RequestFailed(err)) => {
                 // If we failed to request commands, this could be the service
                 // could be down.  Log it, but keep going.
                 error!("error polling the service for commands: {:?}", err);
+                Ok(Self {
+                    last_poll_command: result,
+                    ..self
+                })
             }
             Err(PollCommandError::RequestParseFailed(err)) => {
                 bail!("poll commands failed: {:?}", err);
@@ -321,22 +356,18 @@ impl Agent {
                     bail!("repeated command claim attempt failures: {:?}", err);
                 }
                 error!("error claiming command from the service: {:?}", err);
+                Ok(Self {
+                    last_poll_command: result,
+                    ..self
+                })
             }
         }
-
-        self.last_poll_command = result;
-
-        Ok(())
     }
 
-    async fn sleep(&mut self) {
+    async fn sleep(&self) {
         let delay = time::Duration::from_secs(30);
         time::sleep(delay).await;
     }
-
-    fn scheduler(&mut self) -> Result<&mut Scheduler> {
-        self.scheduler.as_mut().ok_or_else(scheduler_error)
-    }
 }
 
 // The agent owns a `Scheduler`, which it must consume when driving its state
diff --git a/src/agent/onefuzz-agent/src/agent/tests.rs b/src/agent/onefuzz-agent/src/agent/tests.rs
index 13929aad55..f94c40f6fe 100644
--- a/src/agent/onefuzz-agent/src/agent/tests.rs
+++ b/src/agent/onefuzz-agent/src/agent/tests.rs
@@ -83,12 +83,12 @@ impl Fixture {
 
 #[tokio::test]
 async fn test_update_free_no_work() {
-    let mut agent = Fixture.agent();
+    let agent = Fixture.agent();
 
-    let done = agent.update().await.unwrap();
+    let (agent, done) = agent.update().await.unwrap();
     assert!(!done);
 
-    assert!(matches!(agent.scheduler().unwrap(), Scheduler::Free(..)));
+    assert!(matches!(agent.scheduler.unwrap(), Scheduler::Free(..)));
 
     let double: &WorkQueueDouble = agent.work_queue.downcast_ref().unwrap();
     let claimed_worksets = double
@@ -109,13 +109,9 @@ async fn test_update_free_has_work() {
         .available
         .push(Fixture.message());
 
-    let done = agent.update().await.unwrap();
+    let (agent, done) = agent.update().await.unwrap();
     assert!(!done);
-
-    assert!(matches!(
-        agent.scheduler().unwrap(),
-        Scheduler::SettingUp(..)
-    ));
+    assert!(matches!(agent.scheduler.unwrap(), Scheduler::SettingUp(..)));
 
     let double: &WorkQueueDouble = agent.work_queue.downcast_ref().unwrap();
     let claimed_worksets = double
@@ -149,8 +145,10 @@ async fn test_emitted_state() {
         .available
         .push(Fixture.message());
 
+    let mut done;
     for _i in 0..10 {
-        if agent.update().await.unwrap() {
+        (agent, done) = agent.update().await.unwrap();
+        if done {
             break;
         }
     }
@@ -181,8 +179,8 @@ async fn test_emitted_state() {
         }),
     ];
     let coordinator: &CoordinatorDouble = agent.coordinator.downcast_ref().unwrap();
-    let events = &coordinator.events;
-    assert_eq!(events, &expected_events);
+    let events = &coordinator.events.read().await;
+    assert_eq!(&events.to_vec(), &expected_events);
 }
 
 #[tokio::test]
@@ -206,8 +204,10 @@ async fn test_emitted_state_failed_setup() {
         .available
         .push(Fixture.message());
 
+    let mut done;
     for _i in 0..10 {
-        if agent.update().await.unwrap() {
+        (agent, done) = agent.update().await.unwrap();
+        if done {
             break;
         }
     }
@@ -223,7 +223,7 @@ async fn test_emitted_state_failed_setup() {
         }),
     ];
     let coordinator: &CoordinatorDouble = agent.coordinator.downcast_ref().unwrap();
-    let events = &coordinator.events;
+    let events = &coordinator.events.read().await.to_vec();
     assert_eq!(events, &expected_events);
 
     // TODO: at some point, the underlying tests should be updated to not write
diff --git a/src/agent/onefuzz-agent/src/commands.rs b/src/agent/onefuzz-agent/src/commands.rs
index a613c8550a..8a62748c1a 100644
--- a/src/agent/onefuzz-agent/src/commands.rs
+++ b/src/agent/onefuzz-agent/src/commands.rs
@@ -25,7 +25,7 @@ const ONEFUZZ_SERVICE_USER: &str = "onefuzz";
 #[cfg(target_family = "windows")]
 static SET_PERMISSION_ONCE: OnceCell<()> = OnceCell::const_new();
 
-#[derive(Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Debug, Deserialize, Eq, PartialEq, Serialize, Clone)]
 pub struct SshKeyInfo {
     pub public_key: Secret<String>,
 }
diff --git a/src/agent/onefuzz-agent/src/config.rs b/src/agent/onefuzz-agent/src/config.rs
index d26d54e7f0..a9a8c650dd 100644
--- a/src/agent/onefuzz-agent/src/config.rs
+++ b/src/agent/onefuzz-agent/src/config.rs
@@ -319,13 +319,12 @@ impl Registration {
     pub async fn load_existing(config: StaticConfig) -> Result<Self> {
         let dynamic_config = DynamicConfig::load().await?;
         let machine_id = config.machine_identity.machine_id;
-        let mut registration = Self {
+        let registration = Self {
             config,
             dynamic_config,
             machine_id,
         };
-        registration.renew().await?;
-        Ok(registration)
+        registration.renew().await
     }
 
     pub async fn create_managed(config: StaticConfig) -> Result<Self> {
@@ -336,7 +335,7 @@ impl Registration {
         Self::create(config, false, DEFAULT_REGISTRATION_CREATE_TIMEOUT).await
     }
 
-    pub async fn renew(&mut self) -> Result<()> {
+    pub async fn renew(&self) -> Result<Self> {
         info!("renewing registration");
         let token = self.config.credentials.access_token().await?;
 
@@ -355,9 +354,13 @@ impl Registration {
             .await
             .context("Registration.renew request body")?;
 
-        self.dynamic_config = response.json().await?;
-        self.dynamic_config.save().await?;
+        let dynamic_config: DynamicConfig = response.json().await?;
+        dynamic_config.save().await?;
 
-        Ok(())
+        Ok(Self {
+            dynamic_config,
+            config: self.config.clone(),
+            machine_id: self.machine_id,
+        })
     }
 }
diff --git a/src/agent/onefuzz-agent/src/coordinator.rs b/src/agent/onefuzz-agent/src/coordinator.rs
index d940d46d8a..e63f250b11 100644
--- a/src/agent/onefuzz-agent/src/coordinator.rs
+++ b/src/agent/onefuzz-agent/src/coordinator.rs
@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+use std::sync::Arc;
+
 use anyhow::{Context, Error, Result};
 use downcast_rs::Downcast;
 use onefuzz::{auth::AccessToken, http::ResponseExt, process::Output};
@@ -9,6 +11,7 @@ use reqwest_retry::{
     is_auth_failure, RetryCheck, SendRetry, DEFAULT_RETRY_PERIOD, MAX_RETRY_ATTEMPTS,
 };
 use serde::Serialize;
+use tokio::sync::RwLock;
 use uuid::Uuid;
 
 use crate::commands::SshKeyInfo;
@@ -16,12 +19,12 @@ use crate::config::Registration;
 use crate::work::{TaskId, WorkSet};
 use crate::worker::WorkerEvent;
 
-#[derive(Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Debug, Deserialize, Eq, PartialEq, Serialize, Clone)]
 pub struct StopTask {
     pub task_id: TaskId,
 }
 
-#[derive(Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Debug, Deserialize, Eq, PartialEq, Serialize, Clone)]
 #[serde(rename_all = "snake_case")]
 pub enum NodeCommand {
     AddSshKey(SshKeyInfo),
@@ -153,9 +156,9 @@ pub struct TaskInfo {
 pub trait ICoordinator: Downcast {
     async fn poll_commands(&mut self) -> Result<Option<NodeCommand>, PollCommandError>;
 
-    async fn emit_event(&mut self, event: NodeEvent) -> Result<()>;
+    async fn emit_event(&self, event: NodeEvent) -> Result<()>;
 
-    async fn can_schedule(&mut self, work: &WorkSet) -> Result<CanSchedule>;
+    async fn can_schedule(&self, work: &WorkSet) -> Result<CanSchedule>;
 }
 
 impl_downcast!(ICoordinator);
@@ -163,15 +166,15 @@ impl_downcast!(ICoordinator);
 #[async_trait]
 impl ICoordinator for Coordinator {
     async fn poll_commands(&mut self) -> Result<Option<NodeCommand>, PollCommandError> {
-        self.poll_commands().await
+        Coordinator::poll_commands(self).await
     }
 
-    async fn emit_event(&mut self, event: NodeEvent) -> Result<()> {
-        self.emit_event(event).await
+    async fn emit_event(&self, event: NodeEvent) -> Result<()> {
+        Coordinator::emit_event(self, event).await
     }
 
-    async fn can_schedule(&mut self, work_set: &WorkSet) -> Result<CanSchedule> {
-        self.can_schedule(work_set).await
+    async fn can_schedule(&self, work_set: &WorkSet) -> Result<CanSchedule> {
+        Coordinator::can_schedule(self, work_set).await
     }
 }
 
@@ -184,7 +187,7 @@ pub enum PollCommandError {
 pub struct Coordinator {
     client: Client,
     registration: Registration,
-    token: AccessToken,
+    token: Arc<RwLock<AccessToken>>,
 }
 
 impl Coordinator {
@@ -195,7 +198,7 @@ impl Coordinator {
         Ok(Self {
             client,
             registration,
-            token,
+            token: Arc::new(RwLock::new(token)),
         })
     }
 
@@ -203,7 +206,7 @@ impl Coordinator {
     ///
     /// If the request fails due to an expired access token, we will retry once
     /// with a fresh one.
-    pub async fn poll_commands(&mut self) -> Result<Option<NodeCommand>, PollCommandError> {
+    pub async fn poll_commands(&self) -> Result<Option<NodeCommand>, PollCommandError> {
         let request = PollCommandsRequest {
             machine_id: self.registration.machine_id,
         };
@@ -241,7 +244,7 @@ impl Coordinator {
         }
     }
 
-    pub async fn emit_event(&mut self, event: NodeEvent) -> Result<()> {
+    pub async fn emit_event(&self, event: NodeEvent) -> Result<()> {
         let envelope = NodeEventEnvelope {
             event,
             machine_id: self.registration.machine_id,
@@ -255,7 +258,7 @@ impl Coordinator {
         Ok(())
     }
 
-    async fn can_schedule(&mut self, work_set: &WorkSet) -> Result<CanSchedule> {
+    async fn can_schedule(&self, work_set: &WorkSet) -> Result<CanSchedule> {
         // Temporary: assume one work unit per work set.
         //
         // In the future, we will probably want the same behavior, but we will
@@ -283,11 +286,23 @@ impl Coordinator {
         Ok(can_schedule)
     }
 
-    async fn send_request(&mut self, request: RequestBuilder) -> Result<Response> {
+    async fn get_token(&self) -> Result<AccessToken> {
+        let token = self.token.read().await;
+        Ok(token.clone())
+    }
+
+    async fn refresh_token(&self) -> Result<AccessToken> {
+        let mut token = self.token.write().await;
+        *token = self.registration.config.credentials.access_token().await?;
+        Ok(token.clone())
+    }
+
+    async fn send_request(&self, request: RequestBuilder) -> Result<Response> {
+        let token = self.get_token().await?;
         let mut response = request
             .try_clone()
             .ok_or_else(|| anyhow!("unable to clone request"))?
-            .bearer_auth(self.token.secret().expose_ref())
+            .bearer_auth(token.secret().expose_ref())
             .send_retry(
                 |code| match code {
                     StatusCode::UNAUTHORIZED => RetryCheck::Fail,
@@ -303,13 +318,13 @@ impl Coordinator {
             debug!("access token expired, renewing");
 
             // If we didn't succeed due to authorization, refresh our token,
-            self.token = self.registration.config.credentials.access_token().await?;
+            let token = self.refresh_token().await?;
 
             debug!("retrying request after refreshing access token");
 
             // And try one more time.
             response = request
-                .bearer_auth(self.token.secret().expose_ref())
+                .bearer_auth(token.secret().expose_ref())
                 .send_retry_default()
                 .await
                 .context("Coordinator.send after refreshing access token");
diff --git a/src/agent/onefuzz-agent/src/coordinator/double.rs b/src/agent/onefuzz-agent/src/coordinator/double.rs
index 6abbe77140..f7c488f2c2 100644
--- a/src/agent/onefuzz-agent/src/coordinator/double.rs
+++ b/src/agent/onefuzz-agent/src/coordinator/double.rs
@@ -5,22 +5,24 @@ use super::*;
 
 #[derive(Debug, Default)]
 pub struct CoordinatorDouble {
-    pub commands: Vec<NodeCommand>,
-    pub events: Vec<NodeEvent>,
+    pub commands: Arc<RwLock<Vec<NodeCommand>>>,
+    pub events: Arc<RwLock<Vec<NodeEvent>>>,
 }
 
 #[async_trait]
 impl ICoordinator for CoordinatorDouble {
     async fn poll_commands(&mut self) -> Result<Option<NodeCommand>, PollCommandError> {
-        Ok(self.commands.pop())
+        let mut commands = self.commands.write().await;
+        Ok(commands.pop())
     }
 
-    async fn emit_event(&mut self, event: NodeEvent) -> Result<()> {
-        self.events.push(event);
+    async fn emit_event(&self, event: NodeEvent) -> Result<()> {
+        let mut events = self.events.write().await;
+        events.push(event);
         Ok(())
     }
 
-    async fn can_schedule(&mut self, _work: &WorkSet) -> Result<CanSchedule> {
+    async fn can_schedule(&self, _work: &WorkSet) -> Result<CanSchedule> {
         Ok(CanSchedule {
             allowed: true,
             work_stopped: true,
diff --git a/src/agent/onefuzz-agent/src/debug.rs b/src/agent/onefuzz-agent/src/debug.rs
index 82072e7825..9df0d48592 100644
--- a/src/agent/onefuzz-agent/src/debug.rs
+++ b/src/agent/onefuzz-agent/src/debug.rs
@@ -180,7 +180,7 @@ fn debug_run_worker(opt: RunWorkerOpt) -> Result<()> {
 
 async fn run_worker(mut work_set: WorkSet) -> Result<Vec<WorkerEvent>> {
     use crate::setup::SetupRunner;
-    let mut setup_runner = SetupRunner {
+    let setup_runner = SetupRunner {
         machine_id: Uuid::new_v4(),
     };
     setup_runner.run(&work_set).await?;
diff --git a/src/agent/onefuzz-agent/src/main.rs b/src/agent/onefuzz-agent/src/main.rs
index 38ca6ef621..c2eda46675 100644
--- a/src/agent/onefuzz-agent/src/main.rs
+++ b/src/agent/onefuzz-agent/src/main.rs
@@ -306,7 +306,7 @@ async fn run_agent(config: StaticConfig, reset_node: bool) -> Result<()> {
     let mut coordinator = coordinator::Coordinator::new(registration.clone()).await?;
     debug!("initialized coordinator");
 
-    let mut reboot = reboot::Reboot;
+    let reboot = reboot::Reboot;
     let reboot_context = reboot.load_context().await?;
     if reset_node {
         WorkSet::remove_context(config.machine_identity.machine_id).await?;
@@ -331,7 +331,7 @@ async fn run_agent(config: StaticConfig, reset_node: bool) -> Result<()> {
         ),
         None => None,
     };
-    let mut agent = agent::Agent::new(
+    let agent = agent::Agent::new(
         Box::new(coordinator),
         Box::new(reboot),
         scheduler,
diff --git a/src/agent/onefuzz-agent/src/reboot.rs b/src/agent/onefuzz-agent/src/reboot.rs
index 0ffd4ef0ac..7584cea858 100644
--- a/src/agent/onefuzz-agent/src/reboot.rs
+++ b/src/agent/onefuzz-agent/src/reboot.rs
@@ -12,26 +12,26 @@ use crate::work::*;
 
 #[async_trait]
 pub trait IReboot: Downcast {
-    async fn save_context(&mut self, ctx: RebootContext) -> Result<()>;
+    async fn save_context(&self, ctx: RebootContext) -> Result<()>;
 
-    async fn load_context(&mut self) -> Result<Option<RebootContext>>;
+    async fn load_context(&self) -> Result<Option<RebootContext>>;
 
-    fn invoke(&mut self) -> Result<()>;
+    fn invoke(&self) -> Result<()>;
 }
 
 impl_downcast!(IReboot);
 
 #[async_trait]
 impl IReboot for Reboot {
-    async fn save_context(&mut self, ctx: RebootContext) -> Result<()> {
+    async fn save_context(&self, ctx: RebootContext) -> Result<()> {
         self.save_context(ctx).await
     }
 
-    async fn load_context(&mut self) -> Result<Option<RebootContext>> {
+    async fn load_context(&self) -> Result<Option<RebootContext>> {
         self.load_context().await
     }
 
-    fn invoke(&mut self) -> Result<()> {
+    fn invoke(&self) -> Result<()> {
         self.invoke()
     }
 }
@@ -39,7 +39,7 @@ impl IReboot for Reboot {
 pub struct Reboot;
 
 impl Reboot {
-    pub async fn save_context(&mut self, ctx: RebootContext) -> Result<()> {
+    pub async fn save_context(&self, ctx: RebootContext) -> Result<()> {
         let path = reboot_context_path()?;
 
         info!("saving reboot context to: {}", path.display());
@@ -54,7 +54,7 @@ impl Reboot {
         Ok(())
     }
 
-    pub async fn load_context(&mut self) -> Result<Option<RebootContext>> {
+    pub async fn load_context(&self) -> Result<Option<RebootContext>> {
         use std::io::ErrorKind;
         let path = reboot_context_path()?;
 
@@ -82,7 +82,7 @@ impl Reboot {
     }
 
     #[cfg(target_family = "unix")]
-    pub fn invoke(&mut self) -> Result<()> {
+    pub fn invoke(&self) -> Result<()> {
         info!("invoking local reboot command");
 
         Command::new("reboot").arg("-f").status()?;
@@ -91,7 +91,7 @@ impl Reboot {
     }
 
     #[cfg(target_family = "windows")]
-    pub fn invoke(&mut self) -> Result<()> {
+    pub fn invoke(&self) -> Result<()> {
         info!("invoking local reboot command");
 
         Command::new("powershell.exe")
diff --git a/src/agent/onefuzz-agent/src/reboot/double.rs b/src/agent/onefuzz-agent/src/reboot/double.rs
index e63e474172..ab5027b948 100644
--- a/src/agent/onefuzz-agent/src/reboot/double.rs
+++ b/src/agent/onefuzz-agent/src/reboot/double.rs
@@ -1,27 +1,45 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+use std::sync::{
+    atomic::{self, AtomicBool},
+    Arc,
+};
+
+use tokio::sync::RwLock;
+
 use super::*;
 
-#[derive(Clone, Debug, Default)]
+#[derive(Debug, Default)]
 pub struct RebootDouble {
-    pub saved: Vec<RebootContext>,
-    pub invoked: bool,
+    pub saved: Arc<RwLock<Vec<RebootContext>>>,
+    pub invoked: AtomicBool,
+}
+
+impl Clone for RebootDouble {
+    fn clone(&self) -> Self {
+        Self {
+            saved: self.saved.clone(),
+            invoked: AtomicBool::new(self.invoked.load(atomic::Ordering::SeqCst)),
+        }
+    }
 }
 
 #[async_trait]
 impl IReboot for RebootDouble {
-    async fn save_context(&mut self, ctx: RebootContext) -> Result<()> {
-        self.saved.push(ctx);
+    async fn save_context(&self, ctx: RebootContext) -> Result<()> {
+        let mut saved = self.saved.write().await;
+        saved.push(ctx);
         Ok(())
     }
 
-    async fn load_context(&mut self) -> Result<Option<RebootContext>> {
-        Ok(self.saved.pop())
+    async fn load_context(&self) -> Result<Option<RebootContext>> {
+        let mut saved = self.saved.write().await;
+        Ok(saved.pop())
     }
 
-    fn invoke(&mut self) -> Result<()> {
-        self.invoked = true;
+    fn invoke(&self) -> Result<()> {
+        self.invoked.swap(true, atomic::Ordering::SeqCst);
         Ok(())
     }
 }
diff --git a/src/agent/onefuzz-agent/src/scheduler.rs b/src/agent/onefuzz-agent/src/scheduler.rs
index 0283c06f2a..b7cca0da45 100644
--- a/src/agent/onefuzz-agent/src/scheduler.rs
+++ b/src/agent/onefuzz-agent/src/scheduler.rs
@@ -55,18 +55,22 @@ impl Scheduler {
         Self::default()
     }
 
-    pub async fn execute_command(&mut self, cmd: &NodeCommand, managed: bool) -> Result<()> {
+    pub async fn execute_command(self, cmd: NodeCommand, managed: bool) -> Result<Self> {
         match cmd {
             NodeCommand::AddSshKey(ssh_key_info) => {
                 if managed {
-                    add_ssh_key(ssh_key_info).await?;
+                    add_ssh_key(&ssh_key_info).await?;
                 } else {
                     warn!("adding ssh keys only supported on managed nodes");
                 }
+                Ok(self)
             }
             NodeCommand::StopTask(stop_task) => {
                 if let Scheduler::Busy(state) = self {
-                    state.stop(stop_task.task_id)?;
+                    let state = state.stop(stop_task.task_id)?;
+                    Ok(state.into())
+                } else {
+                    Ok(self)
                 }
             }
             NodeCommand::Stop {} => {
@@ -74,7 +78,7 @@ impl Scheduler {
                 let state = State {
                     ctx: Done { cause },
                 };
-                *self = state.into();
+                Ok(state.into())
             }
             NodeCommand::StopIfFree {} => {
                 if let Scheduler::Free(_) = self {
@@ -82,12 +86,12 @@ impl Scheduler {
                     let state = State {
                         ctx: Done { cause },
                     };
-                    *self = state.into();
+                    Ok(state.into())
+                } else {
+                    Ok(self)
                 }
             }
         }
-
-        Ok(())
     }
 }
 
@@ -187,7 +191,7 @@ pub enum SetupDone {
 }
 
 impl State<SettingUp> {
-    pub async fn finish(self, runner: &mut dyn ISetupRunner) -> Result<SetupDone> {
+    pub async fn finish(self, runner: &dyn ISetupRunner) -> Result<SetupDone> {
         let work_set = self.ctx.work_set;
 
         let output = runner.run(&work_set).await;
@@ -289,7 +293,7 @@ impl State<Busy> {
             .all(|worker| worker.as_ref().unwrap().is_done())
     }
 
-    pub fn stop(&mut self, task_id: TaskId) -> Result<()> {
+    pub fn stop(mut self, task_id: TaskId) -> Result<Self> {
         for worker in &mut self.ctx.workers {
             let worker = worker.as_mut().unwrap();
 
@@ -300,7 +304,7 @@ impl State<Busy> {
             }
         }
 
-        Ok(())
+        Ok(self)
     }
 }
 
diff --git a/src/agent/onefuzz-agent/src/setup.rs b/src/agent/onefuzz-agent/src/setup.rs
index fe9dc7bab8..a1caac3abc 100644
--- a/src/agent/onefuzz-agent/src/setup.rs
+++ b/src/agent/onefuzz-agent/src/setup.rs
@@ -24,14 +24,14 @@ pub type SetupOutput = Option<Output>;
 
 #[async_trait]
 pub trait ISetupRunner: Downcast {
-    async fn run(&mut self, work_set: &WorkSet) -> Result<SetupOutput>;
+    async fn run(&self, work_set: &WorkSet) -> Result<SetupOutput>;
 }
 
 impl_downcast!(ISetupRunner);
 
 #[async_trait]
 impl ISetupRunner for SetupRunner {
-    async fn run(&mut self, work_set: &WorkSet) -> Result<SetupOutput> {
+    async fn run(&self, work_set: &WorkSet) -> Result<SetupOutput> {
         self.run(work_set).await
     }
 }
@@ -42,7 +42,7 @@ pub struct SetupRunner {
 }
 
 impl SetupRunner {
-    pub async fn run(&mut self, work_set: &WorkSet) -> Result<SetupOutput> {
+    pub async fn run(&self, work_set: &WorkSet) -> Result<SetupOutput> {
         info!("running setup for work set");
         work_set.save_context(self.machine_id).await?;
         // Download the setup container.
diff --git a/src/agent/onefuzz-agent/src/setup/double.rs b/src/agent/onefuzz-agent/src/setup/double.rs
index 6fac515508..33dc1d0fe5 100644
--- a/src/agent/onefuzz-agent/src/setup/double.rs
+++ b/src/agent/onefuzz-agent/src/setup/double.rs
@@ -1,19 +1,24 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+use std::sync::Arc;
+
+use tokio::sync::RwLock;
+
 use super::*;
 
 #[derive(Clone, Debug, Default)]
 pub struct SetupRunnerDouble {
-    pub ran: Vec<WorkSet>,
+    pub ran: Arc<RwLock<Vec<WorkSet>>>,
     pub script: SetupOutput,
     pub error_message: Option<String>,
 }
 
 #[async_trait]
 impl ISetupRunner for SetupRunnerDouble {
-    async fn run(&mut self, work_set: &WorkSet) -> Result<SetupOutput> {
-        self.ran.push(work_set.clone());
+    async fn run(&self, work_set: &WorkSet) -> Result<SetupOutput> {
+        let mut ran = self.ran.write().await;
+        ran.push(work_set.clone());
         if let Some(error) = self.error_message.clone() {
             anyhow::bail!(error);
         }
diff --git a/src/agent/onefuzz-agent/src/work.rs b/src/agent/onefuzz-agent/src/work.rs
index 34b93af494..c89693d950 100644
--- a/src/agent/onefuzz-agent/src/work.rs
+++ b/src/agent/onefuzz-agent/src/work.rs
@@ -1,14 +1,15 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-use std::io::ErrorKind;
 use std::path::PathBuf;
+use std::{io::ErrorKind, sync::Arc};
 
 use anyhow::{Context, Result};
 use downcast_rs::Downcast;
 use onefuzz::{auth::Secret, blob::BlobContainerUrl, http::is_auth_error};
 use storage_queue::{Message as QueueMessage, QueueClient};
 use tokio::fs;
+use tokio::sync::RwLock;
 use uuid::Uuid;
 
 use crate::config::Registration;
@@ -145,7 +146,7 @@ pub struct Message {
 
 pub struct WorkQueue {
     queue: QueueClient,
-    registration: Registration,
+    registration: Arc<RwLock<Registration>>,
 }
 
 impl WorkQueue {
@@ -155,16 +156,17 @@ impl WorkQueue {
 
         Ok(Self {
             queue,
-            registration,
+            registration: Arc::new(RwLock::new(registration)),
         })
     }
 
     async fn renew(&mut self) -> Result<()> {
-        self.registration
+        let mut registration = self.registration.write().await;
+        *registration = registration
             .renew()
             .await
             .context("unable to renew registration in workqueue")?;
-        let url = self.registration.dynamic_config.work_queue.clone();
+        let url = registration.dynamic_config.work_queue.clone();
         self.queue = QueueClient::new(url)?;
         Ok(())
     }
@@ -207,7 +209,13 @@ impl WorkQueue {
                 Err(err) => {
                     if is_auth_error(&err) {
                         self.renew().await.context("unable to renew registration")?;
-                        let url = self.registration.dynamic_config.work_queue.clone();
+                        let url = self
+                            .registration
+                            .read()
+                            .await
+                            .dynamic_config
+                            .work_queue
+                            .clone();
                         queue_message
                             .update_url(url)
                             .delete()
diff --git a/src/agent/onefuzz-agent/src/worker.rs b/src/agent/onefuzz-agent/src/worker.rs
index c7f556fb8e..3e12523a6e 100644
--- a/src/agent/onefuzz-agent/src/worker.rs
+++ b/src/agent/onefuzz-agent/src/worker.rs
@@ -189,7 +189,7 @@ impl_from_state_for_worker!(Done);
 
 #[async_trait]
 pub trait IWorkerRunner: Downcast {
-    async fn run(&mut self, setup_dir: &Path, work: &WorkUnit) -> Result<Box<dyn IWorkerChild>>;
+    async fn run(&self, setup_dir: &Path, work: &WorkUnit) -> Result<Box<dyn IWorkerChild>>;
 }
 
 impl_downcast!(IWorkerRunner);
@@ -214,7 +214,7 @@ impl WorkerRunner {
 
 #[async_trait]
 impl IWorkerRunner for WorkerRunner {
-    async fn run(&mut self, setup_dir: &Path, work: &WorkUnit) -> Result<Box<dyn IWorkerChild>> {
+    async fn run(&self, setup_dir: &Path, work: &WorkUnit) -> Result<Box<dyn IWorkerChild>> {
         let working_dir = work.working_dir(self.machine_identity.machine_id)?;
 
         debug!("worker working dir = {}", working_dir.display());
@@ -268,12 +268,12 @@ impl IWorkerRunner for WorkerRunner {
 }
 
 trait SuspendableChild {
-    fn suspend(&mut self) -> Result<()>;
+    fn suspend(&self) -> Result<()>;
 }
 
 #[cfg(target_os = "windows")]
 impl SuspendableChild for Child {
-    fn suspend(&mut self) -> Result<()> {
+    fn suspend(&self) -> Result<()> {
         // DebugActiveProcess suspends all threads in the process.
         // https://docs.microsoft.com/en-us/windows/win32/api/debugapi/nf-debugapi-debugactiveprocess#remarks
         let result = unsafe { winapi::um::debugapi::DebugActiveProcess(self.id()) };
@@ -286,7 +286,7 @@ impl SuspendableChild for Child {
 
 #[cfg(target_os = "linux")]
 impl SuspendableChild for Child {
-    fn suspend(&mut self) -> Result<()> {
+    fn suspend(&self) -> Result<()> {
         use nix::sys::signal;
         signal::kill(
             nix::unistd::Pid::from_raw(self.id() as _),
diff --git a/src/agent/onefuzz-agent/src/worker/double.rs b/src/agent/onefuzz-agent/src/worker/double.rs
index 8fa6a918a7..fb64555a76 100644
--- a/src/agent/onefuzz-agent/src/worker/double.rs
+++ b/src/agent/onefuzz-agent/src/worker/double.rs
@@ -10,7 +10,7 @@ pub struct WorkerRunnerDouble {
 
 #[async_trait]
 impl IWorkerRunner for WorkerRunnerDouble {
-    async fn run(&mut self, _setup_dir: &Path, _work: &WorkUnit) -> Result<Box<dyn IWorkerChild>> {
+    async fn run(&self, _setup_dir: &Path, _work: &WorkUnit) -> Result<Box<dyn IWorkerChild>> {
         Ok(Box::new(self.child.clone()))
     }
 }
diff --git a/src/agent/onefuzz-agent/src/worker/tests.rs b/src/agent/onefuzz-agent/src/worker/tests.rs
index 822e30e805..20f857858c 100644
--- a/src/agent/onefuzz-agent/src/worker/tests.rs
+++ b/src/agent/onefuzz-agent/src/worker/tests.rs
@@ -55,7 +55,7 @@ struct RunnerDouble {
 
 #[async_trait]
 impl IWorkerRunner for RunnerDouble {
-    async fn run(&mut self, _setup_dir: &Path, _work: &WorkUnit) -> Result<Box<dyn IWorkerChild>> {
+    async fn run(&self, _setup_dir: &Path, _work: &WorkUnit) -> Result<Box<dyn IWorkerChild>> {
         Ok(Box::new(self.child.clone()))
     }
 }
diff --git a/src/agent/onefuzz-file-format/src/coverage/source/v1.rs b/src/agent/onefuzz-file-format/src/coverage/source/v1.rs
index 4a110795c0..c1eb87d109 100644
--- a/src/agent/onefuzz-file-format/src/coverage/source/v1.rs
+++ b/src/agent/onefuzz-file-format/src/coverage/source/v1.rs
@@ -9,13 +9,18 @@ use debuggable_module::path::FilePath;
 use serde::{Deserialize, Serialize};
 
 pub type SourceFile = String;
-pub type LineNumber = u32;
 pub type HitCount = u32;
+pub use line_number::LineNumber;
 
 #[derive(Deserialize, Serialize)]
 pub struct SourceCoverageJson {
     #[serde(flatten)]
-    pub modules: BTreeMap<SourceFile, BTreeMap<LineNumber, HitCount>>,
+    pub files: BTreeMap<SourceFile, FileCoverageJson>,
+}
+
+#[derive(Deserialize, Serialize)]
+pub struct FileCoverageJson {
+    pub lines: BTreeMap<LineNumber, HitCount>,
 }
 
 impl TryFrom<SourceCoverageJson> for SourceCoverage {
@@ -24,13 +29,13 @@ impl TryFrom<SourceCoverageJson> for SourceCoverage {
     fn try_from(json: SourceCoverageJson) -> Result<Self> {
         let mut source = SourceCoverage::default();
 
-        for (file_path, lines) in json.modules {
+        for (file_path, file_json) in json.files {
             let file_path = FilePath::new(file_path)?;
 
             let mut file = FileCoverage::default();
 
-            for (line, count) in lines {
-                let line = Line::new(line)?;
+            for (line_number, count) in file_json.lines {
+                let line = Line::new(line_number.0)?;
                 let count = Count(count);
                 file.lines.insert(line, count);
             }
@@ -41,3 +46,26 @@ impl TryFrom<SourceCoverageJson> for SourceCoverage {
         Ok(source)
     }
 }
+
+mod line_number {
+    use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+    #[derive(Clone, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
+    pub struct LineNumber(#[serde(with = "self")] pub u32);
+
+    pub fn serialize<S>(val: &u32, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let s = format!("{}", val);
+        serializer.serialize_str(&s)
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<u32, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        s.parse().map_err(serde::de::Error::custom)
+    }
+}
diff --git a/src/agent/onefuzz-file-format/tests/integration.rs b/src/agent/onefuzz-file-format/tests/binary.rs
similarity index 100%
rename from src/agent/onefuzz-file-format/tests/integration.rs
rename to src/agent/onefuzz-file-format/tests/binary.rs
diff --git a/src/agent/onefuzz-file-format/tests/files/source-coverage.v0.json b/src/agent/onefuzz-file-format/tests/files/source-coverage.v0.json
new file mode 100644
index 0000000000..8e156e0859
--- /dev/null
+++ b/src/agent/onefuzz-file-format/tests/files/source-coverage.v0.json
@@ -0,0 +1,18 @@
+[
+    {
+        "file": "src/bin/main.c",
+        "locations": [
+            { "line": 4, "column": 1, "count": 1 },
+            { "line": 9, "column": 2, "count": 0 },
+            { "line": 12, "column": 3, "count": 5 }
+        ]
+    },
+    {
+        "file": "src/lib/common.c",
+        "locations": [
+            { "line": 5, "column": null, "count": 0 },
+            { "line": 5, "column": null, "count": 1 },
+            { "line": 8, "column": null, "count": 0 }
+        ]
+    }
+]
diff --git a/src/agent/onefuzz-file-format/tests/files/source-coverage.v1.json b/src/agent/onefuzz-file-format/tests/files/source-coverage.v1.json
new file mode 100644
index 0000000000..c489fbd8d8
--- /dev/null
+++ b/src/agent/onefuzz-file-format/tests/files/source-coverage.v1.json
@@ -0,0 +1,15 @@
+{
+    "src/bin/main.c": {
+        "lines": {
+            "4": 1,
+            "9": 0,
+            "12": 5
+        }
+    },
+    "src/lib/common.c": {
+        "lines": {
+            "5": 1,
+            "8": 0
+        }
+    }
+}
diff --git a/src/agent/onefuzz-file-format/tests/source.rs b/src/agent/onefuzz-file-format/tests/source.rs
new file mode 100644
index 0000000000..11bf08f536
--- /dev/null
+++ b/src/agent/onefuzz-file-format/tests/source.rs
@@ -0,0 +1,44 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+use pretty_assertions::assert_eq;
+
+use anyhow::Result;
+use coverage::source::{Count, Line, SourceCoverage};
+use debuggable_module::path::FilePath;
+use onefuzz_file_format::coverage::source::{v0, v1};
+
+fn expected_source_coverage() -> Result<SourceCoverage> {
+    let main_path = FilePath::new("src/bin/main.c")?;
+    let common_path = FilePath::new("src/lib/common.c")?;
+
+    let mut source = SourceCoverage::default();
+
+    let main = source.files.entry(main_path).or_default();
+    main.lines.insert(Line::new(4)?, Count(1));
+    main.lines.insert(Line::new(9)?, Count(0));
+    main.lines.insert(Line::new(12)?, Count(5));
+
+    let common = source.files.entry(common_path).or_default();
+    common.lines.insert(Line::new(5)?, Count(1));
+    common.lines.insert(Line::new(8)?, Count(0));
+
+    Ok(source)
+}
+
+#[test]
+fn test_source_coverage_formats() -> Result<()> {
+    let expected = expected_source_coverage()?;
+
+    let v0_text = include_str!("files/source-coverage.v0.json");
+    let v0_json: v0::SourceCoverageJson = serde_json::from_str(v0_text)?;
+    let from_v0 = SourceCoverage::try_from(v0_json)?;
+    assert_eq!(from_v0, expected);
+
+    let v1_text = include_str!("files/source-coverage.v1.json");
+    let v1_json: v1::SourceCoverageJson = serde_json::from_str(v1_text)?;
+    let from_v1 = SourceCoverage::try_from(v1_json)?;
+    assert_eq!(from_v1, expected);
+
+    Ok(())
+}