diff --git a/Cargo.lock b/Cargo.lock
index 8e64dde937..13ad82070a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -462,6 +462,7 @@ dependencies = [
  "async-watch",
  "chrono",
  "client",
+ "clock",
  "collections",
  "command_palette_hooks",
  "context_server",
@@ -476,6 +477,7 @@ dependencies = [
  "html_to_markdown",
  "http_client",
  "indoc",
+ "itertools 0.13.0",
  "language",
  "language_model",
  "language_model_selector",
diff --git a/crates/assistant2/Cargo.toml b/crates/assistant2/Cargo.toml
index c67674b437..8b52a946a7 100644
--- a/crates/assistant2/Cargo.toml
+++ b/crates/assistant2/Cargo.toml
@@ -19,6 +19,7 @@ assets.workspace = true
 assistant_tool.workspace = true
 async-watch.workspace = true
 client.workspace = true
+clock.workspace = true
 chrono.workspace = true
 collections.workspace = true
 command_palette_hooks.workspace = true
@@ -33,6 +34,7 @@ gpui.workspace = true
 handlebars.workspace = true
 html_to_markdown.workspace = true
 http_client.workspace = true
+itertools.workspace = true
 language.workspace = true
 language_model.workspace = true
 language_model_selector.workspace = true
diff --git a/crates/assistant2/src/active_thread.rs b/crates/assistant2/src/active_thread.rs
index 75da3bb11f..bcbc1e8431 100644
--- a/crates/assistant2/src/active_thread.rs
+++ b/crates/assistant2/src/active_thread.rs
@@ -282,11 +282,13 @@ impl ActiveThread {
                     .child(div().p_2p5().text_ui(cx).child(markdown.clone()))
                     .when_some(context, |parent, context| {
                         if !context.is_empty() {
-                            parent.child(h_flex().flex_wrap().gap_1().px_1p5().pb_1p5().children(
-                                context.iter().map(|context| {
-                                    ContextPill::new_added(context.clone(), false, None)
-                                }),
-                            ))
+                            parent.child(
+                                h_flex().flex_wrap().gap_1().px_1p5().pb_1p5().children(
+                                    context.into_iter().map(|context| {
+                                        ContextPill::new_added(context, false, None)
+                                    }),
+                                ),
+                            )
                         } else {
                             parent
                         }
diff --git a/crates/assistant2/src/buffer_codegen.rs b/crates/assistant2/src/buffer_codegen.rs
index aacbcccddf..90d830dea3 100644
--- a/crates/assistant2/src/buffer_codegen.rs
+++ b/crates/assistant2/src/buffer_codegen.rs
@@ -421,8 +421,7 @@ impl CodegenAlternative {
         };
 
         if let Some(context_store) = &self.context_store {
-            let context = context_store.update(cx, |this, _cx| this.context().clone());
-            attach_context_to_message(&mut request_message, context);
+            attach_context_to_message(&mut request_message, context_store.read(cx).snapshot(cx));
         }
 
         request_message.content.push(prompt.into());
@@ -1053,7 +1052,7 @@ mod tests {
         stream::{self},
         Stream,
     };
-    use gpui::{Context, TestAppContext};
+    use gpui::TestAppContext;
     use indoc::indoc;
     use language::{
         language_settings, tree_sitter_rust, Buffer, Language, LanguageConfig, LanguageMatcher,
diff --git a/crates/assistant2/src/context.rs b/crates/assistant2/src/context.rs
index 0620707e47..55a0b71ba7 100644
--- a/crates/assistant2/src/context.rs
+++ b/crates/assistant2/src/context.rs
@@ -1,8 +1,17 @@
-use gpui::SharedString;
+use std::path::Path;
+use std::rc::Rc;
+use std::sync::Arc;
+
+use collections::BTreeMap;
+use gpui::{AppContext, Model, SharedString};
+use language::Buffer;
 use language_model::{LanguageModelRequestMessage, MessageContent};
 use serde::{Deserialize, Serialize};
+use text::BufferId;
 use util::post_inc;
 
+use crate::thread::Thread;
+
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy, Serialize, Deserialize)]
 pub struct ContextId(pub(crate) usize);
 
@@ -14,16 +23,17 @@ impl ContextId {
 
 /// Some context attached to a message in a thread.
 #[derive(Debug, Clone)]
-pub struct Context {
+pub struct ContextSnapshot {
     pub id: ContextId,
     pub name: SharedString,
     pub parent: Option<SharedString>,
     pub tooltip: Option<SharedString>,
     pub kind: ContextKind,
+    /// Text to send to the model. This is not refreshed by `snapshot`.
     pub text: SharedString,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum ContextKind {
     File,
     Directory,
@@ -31,18 +41,139 @@ pub enum ContextKind {
     Thread,
 }
 
+#[derive(Debug)]
+pub enum Context {
+    File(FileContext),
+    Directory(DirectoryContext),
+    FetchedUrl(FetchedUrlContext),
+    Thread(ThreadContext),
+}
+
+impl Context {
+    pub fn id(&self) -> ContextId {
+        match self {
+            Self::File(file) => file.id,
+            Self::Directory(directory) => directory.snapshot.id,
+            Self::FetchedUrl(url) => url.id,
+            Self::Thread(thread) => thread.id,
+        }
+    }
+}
+
+// TODO: Model<Buffer> holds onto the buffer even if the file is deleted and closed. Should remove
+// the context from the message editor in this case.
+
+#[derive(Debug)]
+pub struct FileContext {
+    pub id: ContextId,
+    pub buffer: Model<Buffer>,
+    #[allow(unused)]
+    pub version: clock::Global,
+    pub text: SharedString,
+}
+
+#[derive(Debug)]
+pub struct DirectoryContext {
+    #[allow(unused)]
+    pub path: Rc<Path>,
+    // TODO: The choice to make this a BTreeMap was a result of use in a version of
+    // ContextStore::will_include_buffer before I realized that the path logic should be used there
+    // too.
+    #[allow(unused)]
+    pub buffers: BTreeMap<BufferId, (Model<Buffer>, clock::Global)>,
+    pub snapshot: ContextSnapshot,
+}
+
+#[derive(Debug)]
+pub struct FetchedUrlContext {
+    pub id: ContextId,
+    pub url: SharedString,
+    pub text: SharedString,
+}
+
+// TODO: Model<Thread> holds onto the thread even if the thread is deleted. Can either handle this
+// explicitly or have a WeakModel<Thread> and remove during snapshot.
+
+#[derive(Debug)]
+pub struct ThreadContext {
+    pub id: ContextId,
+    pub thread: Model<Thread>,
+    pub text: SharedString,
+}
+
+impl Context {
+    pub fn snapshot(&self, cx: &AppContext) -> Option<ContextSnapshot> {
+        match &self {
+            Self::File(file_context) => {
+                let path = file_context.path(cx)?;
+                let full_path: SharedString = path.to_string_lossy().into_owned().into();
+                let name = match path.file_name() {
+                    Some(name) => name.to_string_lossy().into_owned().into(),
+                    None => full_path.clone(),
+                };
+                let parent = path
+                    .parent()
+                    .and_then(|p| p.file_name())
+                    .map(|p| p.to_string_lossy().into_owned().into());
+
+                Some(ContextSnapshot {
+                    id: self.id(),
+                    name,
+                    parent,
+                    tooltip: Some(full_path),
+                    kind: ContextKind::File,
+                    text: file_context.text.clone(),
+                })
+            }
+            Self::Directory(DirectoryContext { snapshot, .. }) => Some(snapshot.clone()),
+            Self::FetchedUrl(FetchedUrlContext { url, text, id }) => Some(ContextSnapshot {
+                id: *id,
+                name: url.clone(),
+                parent: None,
+                tooltip: None,
+                kind: ContextKind::FetchedUrl,
+                text: text.clone(),
+            }),
+            Self::Thread(thread_context) => {
+                let thread = thread_context.thread.read(cx);
+
+                Some(ContextSnapshot {
+                    id: self.id(),
+                    name: thread.summary().unwrap_or("New thread".into()),
+                    parent: None,
+                    tooltip: None,
+                    kind: ContextKind::Thread,
+                    text: thread_context.text.clone(),
+                })
+            }
+        }
+    }
+}
+
+impl FileContext {
+    pub fn path(&self, cx: &AppContext) -> Option<Arc<Path>> {
+        let buffer = self.buffer.read(cx);
+        if let Some(file) = buffer.file() {
+            Some(file.path().clone())
+        } else {
+            log::error!("Buffer that had a path unexpectedly no longer has a path.");
+            None
+        }
+    }
+}
+
 pub fn attach_context_to_message(
     message: &mut LanguageModelRequestMessage,
-    context: impl IntoIterator<Item = Context>,
+    contexts: impl Iterator<Item = ContextSnapshot>,
 ) {
     let mut file_context = String::new();
     let mut directory_context = String::new();
     let mut fetch_context = String::new();
     let mut thread_context = String::new();
 
-    for context in context.into_iter() {
+    for context in contexts {
         match context.kind {
-            ContextKind::File { .. } => {
+            ContextKind::File => {
                 file_context.push_str(&context.text);
                 file_context.push('\n');
             }
@@ -56,7 +187,7 @@ pub fn attach_context_to_message(
                 fetch_context.push_str(&context.text);
                 fetch_context.push('\n');
             }
-            ContextKind::Thread => {
+            ContextKind::Thread { .. } => {
                 thread_context.push_str(&context.name);
                 thread_context.push('\n');
                 thread_context.push_str(&context.text);
diff --git a/crates/assistant2/src/context_picker/directory_context_picker.rs b/crates/assistant2/src/context_picker/directory_context_picker.rs
index a8c76a1554..2a6d0a7fa8 100644
--- a/crates/assistant2/src/context_picker/directory_context_picker.rs
+++ b/crates/assistant2/src/context_picker/directory_context_picker.rs
@@ -240,7 +240,7 @@ impl PickerDelegate for DirectoryContextPickerDelegate {
         let added = self.context_store.upgrade().map_or(false, |context_store| {
             context_store
                 .read(cx)
-                .included_directory(&path_match.path)
+                .includes_directory(&path_match.path)
                 .is_some()
         });
 
diff --git a/crates/assistant2/src/context_picker/fetch_context_picker.rs b/crates/assistant2/src/context_picker/fetch_context_picker.rs
index 24bee6ea2f..6704150096 100644
--- a/crates/assistant2/src/context_picker/fetch_context_picker.rs
+++ b/crates/assistant2/src/context_picker/fetch_context_picker.rs
@@ -82,10 +82,12 @@ impl FetchContextPickerDelegate {
     }
 
     async fn build_message(http_client: Arc<HttpClientWithUrl>, url: &str) -> Result<String> {
-        let mut url = url.to_owned();
-        if !url.starts_with("https://") && !url.starts_with("http://") {
-            url = format!("https://{url}");
-        }
+        let prefixed_url = if !url.starts_with("https://") && !url.starts_with("http://") {
+            Some(format!("https://{url}"))
+        } else {
+            None
+        };
+        let url = prefixed_url.as_deref().unwrap_or(url);
 
         let mut response = http_client.get(&url, AsyncBody::default(), true).await?;
 
@@ -200,7 +202,7 @@ impl PickerDelegate for FetchContextPickerDelegate {
                 this.delegate
                     .context_store
                     .update(cx, |context_store, _cx| {
-                        if context_store.included_url(&url).is_none() {
+                        if context_store.includes_url(&url).is_none() {
                             context_store.insert_fetched_url(url, text);
                         }
                     })?;
@@ -234,7 +236,7 @@ impl PickerDelegate for FetchContextPickerDelegate {
         cx: &mut ViewContext<Picker<Self>>,
     ) -> Option<Self::ListItem> {
         let added = self.context_store.upgrade().map_or(false, |context_store| {
-            context_store.read(cx).included_url(&self.url).is_some()
+            context_store.read(cx).includes_url(&self.url).is_some()
         });
 
         Some(
diff --git a/crates/assistant2/src/context_picker/file_context_picker.rs b/crates/assistant2/src/context_picker/file_context_picker.rs
index 8b75433569..288483bf2f 100644
--- a/crates/assistant2/src/context_picker/file_context_picker.rs
+++ b/crates/assistant2/src/context_picker/file_context_picker.rs
@@ -11,7 +11,7 @@ use util::ResultExt as _;
 use workspace::Workspace;
 
 use crate::context_picker::{ConfirmBehavior, ContextPicker};
-use crate::context_store::{ContextStore, IncludedFile};
+use crate::context_store::{ContextStore, FileInclusion};
 
 pub struct FileContextPicker {
     picker: View<Picker<FileContextPickerDelegate>>,
@@ -275,10 +275,11 @@ impl PickerDelegate for FileContextPickerDelegate {
             (file_name, Some(directory))
         };
 
-        let added = self
-            .context_store
-            .upgrade()
-            .and_then(|context_store| context_store.read(cx).included_file(&path_match.path));
+        let added = self.context_store.upgrade().and_then(|context_store| {
+            context_store
+                .read(cx)
+                .will_include_file_path(&path_match.path, cx)
+        });
 
         Some(
             ListItem::new(ix)
@@ -295,7 +296,7 @@ impl PickerDelegate for FileContextPickerDelegate {
                         })),
                 )
                 .when_some(added, |el, added| match added {
-                    IncludedFile::Direct(_) => el.end_slot(
+                    FileInclusion::Direct(_) => el.end_slot(
                         h_flex()
                             .gap_1()
                             .child(
@@ -305,7 +306,7 @@ impl PickerDelegate for FileContextPickerDelegate {
                             )
                             .child(Label::new("Added").size(LabelSize::Small)),
                     ),
-                    IncludedFile::InDirectory(dir_name) => {
+                    FileInclusion::InDirectory(dir_name) => {
                         let dir_name = dir_name.to_string_lossy().into_owned();
 
                         el.end_slot(
diff --git a/crates/assistant2/src/context_picker/thread_context_picker.rs b/crates/assistant2/src/context_picker/thread_context_picker.rs
index 86578cb8f7..db09082bda 100644
--- a/crates/assistant2/src/context_picker/thread_context_picker.rs
+++ b/crates/assistant2/src/context_picker/thread_context_picker.rs
@@ -194,7 +194,7 @@ impl PickerDelegate for ThreadContextPickerDelegate {
         let thread = &self.matches[ix];
 
         let added = self.context_store.upgrade().map_or(false, |context_store| {
-            context_store.read(cx).included_thread(&thread.id).is_some()
+            context_store.read(cx).includes_thread(&thread.id).is_some()
         });
 
         Some(
diff --git a/crates/assistant2/src/context_store.rs b/crates/assistant2/src/context_store.rs
index 3ae7bfb9b4..84b4d0b97b 100644
--- a/crates/assistant2/src/context_store.rs
+++ b/crates/assistant2/src/context_store.rs
@@ -3,23 +3,25 @@ use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 use anyhow::{anyhow, bail, Result};
-use collections::{HashMap, HashSet};
-use gpui::{Model, ModelContext, SharedString, Task, WeakView};
+use collections::{BTreeMap, HashMap};
+use gpui::{AppContext, Model, ModelContext, SharedString, Task, WeakView};
 use language::Buffer;
 use project::{ProjectPath, Worktree};
+use text::BufferId;
 use workspace::Workspace;
 
-use crate::thread::Thread;
-use crate::{
-    context::{Context, ContextId, ContextKind},
-    thread::ThreadId,
+use crate::context::{
+    Context, ContextId, ContextKind, ContextSnapshot, DirectoryContext, FetchedUrlContext,
+    FileContext, ThreadContext,
 };
+use crate::thread::{Thread, ThreadId};
 
 pub struct ContextStore {
     workspace: WeakView<Workspace>,
     context: Vec<Context>,
+    // TODO: If an EntityId is used for all context types (like BufferId), can remove ContextId.
     next_context_id: ContextId,
-    files: HashMap<PathBuf, ContextId>,
+    files: BTreeMap<BufferId, ContextId>,
     directories: HashMap<PathBuf, ContextId>,
     threads: HashMap<ThreadId, ContextId>,
     fetched_urls: HashMap<String, ContextId>,
@@ -31,13 +33,22 @@ impl ContextStore {
             workspace,
             context: Vec::new(),
             next_context_id: ContextId(0),
-            files: HashMap::default(),
+            files: BTreeMap::default(),
             directories: HashMap::default(),
             threads: HashMap::default(),
             fetched_urls: HashMap::default(),
         }
     }
 
+    pub fn snapshot<'a>(
+        &'a self,
+        cx: &'a AppContext,
+    ) -> impl Iterator<Item = ContextSnapshot> + 'a {
+        self.context()
+            .iter()
+            .flat_map(|context| context.snapshot(cx))
+    }
+
     pub fn context(&self) -> &Vec<Context> {
         &self.context
     }
@@ -63,64 +74,54 @@ impl ContextStore {
             return Task::ready(Err(anyhow!("failed to read project")));
         };
 
-        let already_included = match self.included_file(&project_path.path) {
-            Some(IncludedFile::Direct(context_id)) => {
-                self.remove_context(&context_id);
-                true
-            }
-            Some(IncludedFile::InDirectory(_)) => true,
-            None => false,
-        };
-        if already_included {
-            return Task::ready(Ok(()));
-        }
-
         cx.spawn(|this, mut cx| async move {
-            let open_buffer_task =
-                project.update(&mut cx, |project, cx| project.open_buffer(project_path, cx))?;
+            let open_buffer_task = project.update(&mut cx, |project, cx| {
+                project.open_buffer(project_path.clone(), cx)
+            })?;
 
             let buffer = open_buffer_task.await?;
+            let buffer_id = buffer.update(&mut cx, |buffer, _cx| buffer.remote_id())?;
+
+            let already_included = this.update(&mut cx, |this, _cx| {
+                match this.will_include_buffer(buffer_id, &project_path.path) {
+                    Some(FileInclusion::Direct(context_id)) => {
+                        this.remove_context(context_id);
+                        true
+                    }
+                    Some(FileInclusion::InDirectory(_)) => true,
+                    None => false,
+                }
+            })?;
+
+            if already_included {
+                return anyhow::Ok(());
+            }
+
             this.update(&mut cx, |this, cx| {
-                this.insert_file(buffer.read(cx));
+                this.insert_file(buffer, cx);
             })?;
 
             anyhow::Ok(())
         })
     }
 
-    pub fn insert_file(&mut self, buffer: &Buffer) {
+    pub fn insert_file(&mut self, buffer_model: Model<Buffer>, cx: &AppContext) {
+        let buffer = buffer_model.read(cx);
         let Some(file) = buffer.file() else {
             return;
         };
 
-        let path = file.path();
+        let mut text = String::new();
+        push_fenced_codeblock(file.path(), buffer.text(), &mut text);
 
         let id = self.next_context_id.post_inc();
-        self.files.insert(path.to_path_buf(), id);
-
-        let full_path: SharedString = path.to_string_lossy().into_owned().into();
-
-        let name = match path.file_name() {
-            Some(name) => name.to_string_lossy().into_owned().into(),
-            None => full_path.clone(),
-        };
-
-        let parent = path
-            .parent()
-            .and_then(|p| p.file_name())
-            .map(|p| p.to_string_lossy().into_owned().into());
-
-        let mut text = String::new();
-        push_fenced_codeblock(path, buffer.text(), &mut text);
-
-        self.context.push(Context {
+        self.files.insert(buffer.remote_id(), id);
+        self.context.push(Context::File(FileContext {
             id,
-            name,
-            parent,
-            tooltip: Some(full_path),
-            kind: ContextKind::File,
+            buffer: buffer_model,
+            version: buffer.version.clone(),
             text: text.into(),
-        });
+        }));
     }
 
     pub fn add_directory(
@@ -136,9 +137,9 @@ impl ContextStore {
             return Task::ready(Err(anyhow!("failed to read project")));
         };
 
-        let already_included = if let Some(context_id) = self.included_directory(&project_path.path)
+        let already_included = if let Some(context_id) = self.includes_directory(&project_path.path)
         {
-            self.remove_context(&context_id);
+            self.remove_context(context_id);
             true
         } else {
             false
@@ -178,23 +179,24 @@ impl ContextStore {
 
             this.update(&mut cx, |this, cx| {
                 let mut text = String::new();
-                let mut added_files = 0;
-
-                for buffer in buffers.into_iter().flatten() {
-                    let buffer = buffer.read(cx);
+                let mut directory_buffers = BTreeMap::new();
+                for buffer_model in buffers {
+                    let buffer_model = buffer_model?;
+                    let buffer = buffer_model.read(cx);
                     let path = buffer.file().map_or(&project_path.path, |file| file.path());
                     push_fenced_codeblock(&path, buffer.text(), &mut text);
-                    added_files += 1;
+                    directory_buffers
+                        .insert(buffer.remote_id(), (buffer_model, buffer.version.clone()));
                 }
 
-                if added_files == 0 {
+                if directory_buffers.is_empty() {
                     bail!(
                         "could not read any text files from {}",
                         &project_path.path.display()
                     );
                 }
 
-                this.insert_directory(&project_path.path, text);
+                this.insert_directory(&project_path.path, directory_buffers, text);
 
                 anyhow::Ok(())
             })??;
@@ -203,7 +205,12 @@ impl ContextStore {
         })
     }
 
-    pub fn insert_directory(&mut self, path: &Path, text: impl Into<SharedString>) {
+    pub fn insert_directory(
+        &mut self,
+        path: &Path,
+        buffers: BTreeMap<BufferId, (Model<Buffer>, clock::Global)>,
+        text: impl Into<SharedString>,
+    ) {
         let id = self.next_context_id.post_inc();
         self.directories.insert(path.to_path_buf(), id);
 
@@ -219,78 +226,104 @@ impl ContextStore {
             .and_then(|p| p.file_name())
             .map(|p| p.to_string_lossy().into_owned().into());
 
-        self.context.push(Context {
-            id,
-            name,
-            parent,
-            tooltip: Some(full_path),
-            kind: ContextKind::Directory,
-            text: text.into(),
-        });
+        self.context.push(Context::Directory(DirectoryContext {
+            path: path.into(),
+            buffers,
+            snapshot: ContextSnapshot {
+                id,
+                name,
+                parent,
+                tooltip: Some(full_path),
+                kind: ContextKind::Directory,
+                text: text.into(),
+            },
+        }));
     }
 
     pub fn add_thread(&mut self, thread: Model<Thread>, cx: &mut ModelContext<Self>) {
-        if let Some(context_id) = self.included_thread(&thread.read(cx).id()) {
-            self.remove_context(&context_id);
+        if let Some(context_id) = self.includes_thread(&thread.read(cx).id()) {
+            self.remove_context(context_id);
         } else {
-            self.insert_thread(thread.read(cx));
+            self.insert_thread(thread, cx);
         }
     }
 
-    pub fn insert_thread(&mut self, thread: &Thread) {
-        let context_id = self.next_context_id.post_inc();
-        self.threads.insert(thread.id().clone(), context_id);
+    pub fn insert_thread(&mut self, thread: Model<Thread>, cx: &AppContext) {
+        let id = self.next_context_id.post_inc();
+        let thread_ref = thread.read(cx);
+        let text = thread_ref.text().into();
 
-        self.context.push(Context {
-            id: context_id,
-            name: thread.summary().unwrap_or("New thread".into()),
-            parent: None,
-            tooltip: None,
-            kind: ContextKind::Thread,
-            text: thread.text().into(),
-        });
+        self.threads.insert(thread_ref.id().clone(), id);
+        self.context
+            .push(Context::Thread(ThreadContext { id, thread, text }));
     }
 
     pub fn insert_fetched_url(&mut self, url: String, text: impl Into<SharedString>) {
-        let context_id = self.next_context_id.post_inc();
-        self.fetched_urls.insert(url.clone(), context_id);
+        let id = self.next_context_id.post_inc();
 
-        self.context.push(Context {
-            id: context_id,
-            name: url.into(),
-            parent: None,
-            tooltip: None,
-            kind: ContextKind::FetchedUrl,
+        self.fetched_urls.insert(url.clone(), id);
+        self.context.push(Context::FetchedUrl(FetchedUrlContext {
+            id,
+            url: url.into(),
             text: text.into(),
-        });
+        }));
     }
 
-    pub fn remove_context(&mut self, id: &ContextId) {
-        let Some(ix) = self.context.iter().position(|context| context.id == *id) else {
+    pub fn remove_context(&mut self, id: ContextId) {
+        let Some(ix) = self.context.iter().position(|context| context.id() == id) else {
             return;
         };
 
-        match self.context.remove(ix).kind {
-            ContextKind::File => {
-                self.files.retain(|_, context_id| context_id != id);
+        match self.context.remove(ix) {
+            Context::File(_) => {
+                self.files.retain(|_, context_id| *context_id != id);
             }
-            ContextKind::Directory => {
-                self.directories.retain(|_, context_id| context_id != id);
+            Context::Directory(_) => {
+                self.directories.retain(|_, context_id| *context_id != id);
             }
-            ContextKind::FetchedUrl => {
-                self.fetched_urls.retain(|_, context_id| context_id != id);
+            Context::FetchedUrl(_) => {
+                self.fetched_urls.retain(|_, context_id| *context_id != id);
             }
-            ContextKind::Thread => {
-                self.threads.retain(|_, context_id| context_id != id);
+            Context::Thread(_) => {
+                self.threads.retain(|_, context_id| *context_id != id);
             }
         }
     }
 
-    pub fn included_file(&self, path: &Path) -> Option<IncludedFile> {
-        if let Some(id) = self.files.get(path) {
-            return Some(IncludedFile::Direct(*id));
+    /// Returns whether the buffer is already included directly in the context, or if it will be
+    /// included in the context via a directory. Directory inclusion is based on paths rather than
+    /// buffer IDs as the directory will be re-scanned.
+    pub fn will_include_buffer(&self, buffer_id: BufferId, path: &Path) -> Option<FileInclusion> {
+        if let Some(context_id) = self.files.get(&buffer_id) {
+            return Some(FileInclusion::Direct(*context_id));
         }
 
+        self.will_include_file_path_via_directory(path)
+    }
+
+    /// Returns whether this file path is already included directly in the context, or if it will be
+    /// included in the context via a directory.
+    pub fn will_include_file_path(&self, path: &Path, cx: &AppContext) -> Option<FileInclusion> {
+        if !self.files.is_empty() {
+            let found_file_context = self.context.iter().find(|context| match &context {
+                Context::File(file_context) => {
+                    if let Some(file_path) = file_context.path(cx) {
+                        *file_path == *path
+                    } else {
+                        false
+                    }
+                }
+                _ => false,
+            });
+            if let Some(context) = found_file_context {
+                return Some(FileInclusion::Direct(context.id()));
+            }
+        }
+
+        self.will_include_file_path_via_directory(path)
+    }
+
+    fn will_include_file_path_via_directory(&self, path: &Path) -> Option<FileInclusion> {
         if self.directories.is_empty() {
             return None;
         }
@@ -299,40 +332,27 @@ impl ContextStore {
 
         while buf.pop() {
             if let Some(_) = self.directories.get(&buf) {
-                return Some(IncludedFile::InDirectory(buf));
+                return Some(FileInclusion::InDirectory(buf));
             }
         }
 
         None
     }
 
-    pub fn included_directory(&self, path: &Path) -> Option<ContextId> {
+    pub fn includes_directory(&self, path: &Path) -> Option<ContextId> {
         self.directories.get(path).copied()
     }
 
-    pub fn included_thread(&self, thread_id: &ThreadId) -> Option<ContextId> {
+    pub fn includes_thread(&self, thread_id: &ThreadId) -> Option<ContextId> {
         self.threads.get(thread_id).copied()
     }
 
-    pub fn included_url(&self, url: &str) -> Option<ContextId> {
+    pub fn includes_url(&self, url: &str) -> Option<ContextId> {
         self.fetched_urls.get(url).copied()
     }
-
-    pub fn duplicated_names(&self) -> HashSet<SharedString> {
-        let mut seen = HashSet::default();
-        let mut dupes = HashSet::default();
-
-        for context in self.context().iter() {
-            if !seen.insert(&context.name) {
-                dupes.insert(context.name.clone());
-            }
-        }
-
-        dupes
-    }
 }
 
-pub enum IncludedFile {
+pub enum FileInclusion {
     Direct(ContextId),
     InDirectory(PathBuf),
 }
diff --git a/crates/assistant2/src/context_strip.rs b/crates/assistant2/src/context_strip.rs
index ded54edc82..f62d799169 100644
--- a/crates/assistant2/src/context_strip.rs
+++ b/crates/assistant2/src/context_strip.rs
@@ -1,10 +1,12 @@
 use std::rc::Rc;
 
+use collections::HashSet;
 use editor::Editor;
 use gpui::{
     AppContext, DismissEvent, EventEmitter, FocusHandle, Model, Subscription, View, WeakModel,
     WeakView,
 };
+use itertools::Itertools;
 use language::Buffer;
 use ui::{prelude::*, KeyBinding, PopoverMenu, PopoverMenuHandle, Tooltip};
 use workspace::Workspace;
@@ -73,11 +75,17 @@ impl ContextStrip {
         let active_item = workspace.read(cx).active_item(cx)?;
 
         let editor = active_item.to_any().downcast::<Editor>().ok()?.read(cx);
-        let active_buffer = editor.buffer().read(cx).as_singleton()?;
+        let active_buffer_model = editor.buffer().read(cx).as_singleton()?;
+        let active_buffer = active_buffer_model.read(cx);
 
-        let path = active_buffer.read(cx).file()?.path();
+        let path = active_buffer.file()?.path();
 
-        if self.context_store.read(cx).included_file(path).is_some() {
+        if self
+            .context_store
+            .read(cx)
+            .will_include_buffer(active_buffer.remote_id(), path)
+            .is_some()
+        {
             return None;
         }
 
@@ -88,7 +96,7 @@ impl ContextStrip {
 
         Some(SuggestedContext::File {
             name,
-            buffer: active_buffer.downgrade(),
+            buffer: active_buffer_model.downgrade(),
         })
     }
 
@@ -106,7 +114,7 @@ impl ContextStrip {
         if self
             .context_store
             .read(cx)
-            .included_thread(active_thread.id())
+            .includes_thread(active_thread.id())
             .is_some()
         {
             return None;
@@ -131,13 +139,24 @@ impl ContextStrip {
 impl Render for ContextStrip {
     fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
         let context_store = self.context_store.read(cx);
-        let context = context_store.context().clone();
+        let context = context_store
+            .context()
+            .iter()
+            .flat_map(|context| context.snapshot(cx))
+            .collect::<Vec<_>>();
         let context_picker = self.context_picker.clone();
         let focus_handle = self.focus_handle.clone();
 
         let suggested_context = self.suggested_context(cx);
 
-        let dupe_names = context_store.duplicated_names();
+        let dupe_names = context
+            .iter()
+            .map(|context| context.name.clone())
+            .sorted()
+            .tuple_windows()
+            .filter(|(a, b)| a == b)
+            .map(|(a, _)| a)
+            .collect::<HashSet<SharedString>>();
 
         h_flex()
             .flex_wrap()
@@ -194,11 +213,11 @@ impl Render for ContextStrip {
                     context.clone(),
                     dupe_names.contains(&context.name),
                     Some({
-                        let context = context.clone();
+                        let id = context.id;
                         let context_store = self.context_store.clone();
                         Rc::new(cx.listener(move |_this, _event, cx| {
                             context_store.update(cx, |this, _cx| {
-                                this.remove_context(&context.id);
+                                this.remove_context(id);
                             });
                             cx.notify();
                         }))
@@ -284,12 +303,12 @@ impl SuggestedContext {
         match self {
             Self::File { buffer, name: _ } => {
                 if let Some(buffer) = buffer.upgrade() {
-                    context_store.insert_file(buffer.read(cx));
+                    context_store.insert_file(buffer, cx);
                 };
             }
             Self::Thread { thread, name: _ } => {
                 if let Some(thread) = thread.upgrade() {
-                    context_store.insert_thread(thread.read(cx));
+                    context_store.insert_thread(thread, cx);
                 };
             }
         }
diff --git a/crates/assistant2/src/message_editor.rs b/crates/assistant2/src/message_editor.rs
index 5621032b8f..e9a7b4fc8e 100644
--- a/crates/assistant2/src/message_editor.rs
+++ b/crates/assistant2/src/message_editor.rs
@@ -147,11 +147,10 @@ impl MessageEditor {
             editor.clear(cx);
             text
         });
-        let context = self
-            .context_store
-            .update(cx, |this, _cx| this.context().clone());
 
-        self.thread.update(cx, |thread, cx| {
+        let thread = self.thread.clone();
+        thread.update(cx, |thread, cx| {
+            let context = self.context_store.read(cx).snapshot(cx).collect::<Vec<_>>();
             thread.insert_user_message(user_message, context, cx);
             let mut request = thread.to_completion_request(request_kind, cx);
 
diff --git a/crates/assistant2/src/terminal_inline_assistant.rs b/crates/assistant2/src/terminal_inline_assistant.rs
index d3773de0a2..1b75dc2c3e 100644
--- a/crates/assistant2/src/terminal_inline_assistant.rs
+++ b/crates/assistant2/src/terminal_inline_assistant.rs
@@ -245,10 +245,10 @@ impl TerminalInlineAssistant {
             cache: false,
         };
 
-        let context = assist
-            .context_store
-            .update(cx, |this, _cx| this.context().clone());
-        attach_context_to_message(&mut request_message, context);
+        attach_context_to_message(
+            &mut request_message,
+            assist.context_store.read(cx).snapshot(cx),
+        );
 
         request_message.content.push(prompt.into());
 
diff --git a/crates/assistant2/src/thread.rs b/crates/assistant2/src/thread.rs
index f3de36f8a7..b2949680c4 100644
--- a/crates/assistant2/src/thread.rs
+++ b/crates/assistant2/src/thread.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 use anyhow::Result;
 use assistant_tool::ToolWorkingSet;
 use chrono::{DateTime, Utc};
-use collections::{HashMap, HashSet};
+use collections::{BTreeMap, HashMap, HashSet};
 use futures::future::Shared;
 use futures::{FutureExt as _, StreamExt as _};
 use gpui::{AppContext, EventEmitter, ModelContext, SharedString, Task};
@@ -17,7 +17,7 @@ use serde::{Deserialize, Serialize};
 use util::{post_inc, TryFutureExt as _};
 use uuid::Uuid;
 
-use crate::context::{attach_context_to_message, Context, ContextId};
+use crate::context::{attach_context_to_message, ContextId, ContextSnapshot};
 
 #[derive(Debug, Clone, Copy)]
 pub enum RequestKind {
@@ -64,7 +64,7 @@ pub struct Thread {
     pending_summary: Task<Option<()>>,
     messages: Vec<Message>,
     next_message_id: MessageId,
-    context: HashMap<ContextId, Context>,
+    context: BTreeMap<ContextId, ContextSnapshot>,
     context_by_message: HashMap<MessageId, Vec<ContextId>>,
     completion_count: usize,
     pending_completions: Vec<PendingCompletion>,
@@ -83,7 +83,7 @@ impl Thread {
             pending_summary: Task::ready(None),
             messages: Vec::new(),
             next_message_id: MessageId(0),
-            context: HashMap::default(),
+            context: BTreeMap::default(),
             context_by_message: HashMap::default(),
             completion_count: 0,
             pending_completions: Vec::new(),
@@ -131,7 +131,7 @@ impl Thread {
         &self.tools
     }
 
-    pub fn context_for_message(&self, id: MessageId) -> Option<Vec<Context>> {
+    pub fn context_for_message(&self, id: MessageId) -> Option<Vec<ContextSnapshot>> {
         let context = self.context_by_message.get(&id)?;
         Some(
             context
@@ -149,7 +149,7 @@ impl Thread {
     pub fn insert_user_message(
         &mut self,
         text: impl Into<String>,
-        context: Vec<Context>,
+        context: Vec<ContextSnapshot>,
         cx: &mut ModelContext<Self>,
     ) {
         let message_id = self.insert_message(Role::User, text, cx);
diff --git a/crates/assistant2/src/ui/context_pill.rs b/crates/assistant2/src/ui/context_pill.rs
index c6d2d3e7b0..e70169ed5f 100644
--- a/crates/assistant2/src/ui/context_pill.rs
+++ b/crates/assistant2/src/ui/context_pill.rs
@@ -3,12 +3,12 @@ use std::rc::Rc;
 use gpui::ClickEvent;
 use ui::{prelude::*, IconButtonShape, Tooltip};
 
-use crate::context::{Context, ContextKind};
+use crate::context::{ContextKind, ContextSnapshot};
 
 #[derive(IntoElement)]
 pub enum ContextPill {
     Added {
-        context: Context,
+        context: ContextSnapshot,
         dupe_name: bool,
         on_remove: Option<Rc<dyn Fn(&ClickEvent, &mut WindowContext)>>,
     },
@@ -21,7 +21,7 @@ pub enum ContextPill {
 
 impl ContextPill {
     pub fn new_added(
-        context: Context,
+        context: ContextSnapshot,
         dupe_name: bool,
         on_remove: Option<Rc<dyn Fn(&ClickEvent, &mut WindowContext)>>,
     ) -> Self {
@@ -49,10 +49,10 @@ impl ContextPill {
         }
     }
 
-    pub fn kind(&self) -> &ContextKind {
+    pub fn kind(&self) -> ContextKind {
         match self {
-            Self::Added { context, .. } => &context.kind,
-            Self::Suggested { kind, .. } => kind,
+            Self::Added { context, .. } => context.kind,
+            Self::Suggested { kind, .. } => *kind,
         }
     }
 }