Include mention context in acp-based native agent (#36006)

Also adds data-layer support for symbols, thread, and rules.

Release Notes:

- N/A

---------

Co-authored-by: Cole Miller <cole@zed.dev>

Cargo.lock

@@ -29,6 +29,7 @@ dependencies = [
  "tempfile",
  "terminal",
  "ui",
+ "url",
  "util",
  "workspace-hack",
 ]

crates/acp_thread/Cargo.toml

@@ -34,6 +34,7 @@ settings.workspace = true
 smol.workspace = true
 terminal.workspace = true
 ui.workspace = true
+url.workspace = true
 util.workspace = true
 workspace-hack.workspace = true
 

crates/acp_thread/src/acp_thread.rs

@@ -1,13 +1,15 @@
 mod connection;
 mod diff;
+mod mention;
 mod terminal;
 
 pub use connection::*;
 pub use diff::*;
+pub use mention::*;
 pub use terminal::*;
 
 use action_log::ActionLog;
-use agent_client_protocol as acp;
+use agent_client_protocol::{self as acp};
 use anyhow::{Context as _, Result};
 use editor::Bias;
 use futures::{FutureExt, channel::oneshot, future::BoxFuture};
@@ -21,12 +23,7 @@ use std::error::Error;
 use std::fmt::Formatter;
 use std::process::ExitStatus;
 use std::rc::Rc;
-use std::{
-    fmt::Display,
-    mem,
-    path::{Path, PathBuf},
-    sync::Arc,
-};
+use std::{fmt::Display, mem, path::PathBuf, sync::Arc};
 use ui::App;
 use util::ResultExt;
 
@@ -53,38 +50,6 @@ impl UserMessage {
     }
 }
 
-#[derive(Debug)]
-pub struct MentionPath<'a>(&'a Path);
-
-impl<'a> MentionPath<'a> {
-    const PREFIX: &'static str = "@file:";
-
-    pub fn new(path: &'a Path) -> Self {
-        MentionPath(path)
-    }
-
-    pub fn try_parse(url: &'a str) -> Option<Self> {
-        let path = url.strip_prefix(Self::PREFIX)?;
-        Some(MentionPath(Path::new(path)))
-    }
-
-    pub fn path(&self) -> &Path {
-        self.0
-    }
-}
-
-impl Display for MentionPath<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "[@{}]({}{})",
-            self.0.file_name().unwrap_or_default().display(),
-            Self::PREFIX,
-            self.0.display()
-        )
-    }
-}
-
 #[derive(Debug, PartialEq)]
 pub struct AssistantMessage {
     pub chunks: Vec<AssistantMessageChunk>,
@@ -367,16 +332,24 @@ impl ContentBlock {
     ) {
         let new_content = match block {
             acp::ContentBlock::Text(text_content) => text_content.text.clone(),
-            acp::ContentBlock::ResourceLink(resource_link) => {
-                if let Some(path) = resource_link.uri.strip_prefix("file://") {
-                    format!("{}", MentionPath(path.as_ref()))
+            acp::ContentBlock::Resource(acp::EmbeddedResource {
+                resource:
+                    acp::EmbeddedResourceResource::TextResourceContents(acp::TextResourceContents {
+                        uri,
+                        ..
+                    }),
+                ..
+            }) => {
+                if let Some(uri) = MentionUri::parse(&uri).log_err() {
+                    uri.to_link()
                 } else {
-                    resource_link.uri.clone()
+                    uri.clone()
                 }
             }
             acp::ContentBlock::Image(_)
             | acp::ContentBlock::Audio(_)
-            | acp::ContentBlock::Resource(_) => String::new(),
+            | acp::ContentBlock::Resource(acp::EmbeddedResource { .. })
+            | acp::ContentBlock::ResourceLink(_) => String::new(),
         };
 
         match self {
@@ -1329,7 +1302,7 @@ mod tests {
     use serde_json::json;
     use settings::SettingsStore;
     use smol::stream::StreamExt as _;
-    use std::{cell::RefCell, rc::Rc, time::Duration};
+    use std::{cell::RefCell, path::Path, rc::Rc, time::Duration};
 
     use util::path;
 

crates/acp_thread/src/mention.rs

@@ -0,0 +1,122 @@
+use agent_client_protocol as acp;
+use anyhow::{Result, bail};
+use std::path::PathBuf;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum MentionUri {
+    File(PathBuf),
+    Symbol(PathBuf, String),
+    Thread(acp::SessionId),
+    Rule(String),
+}
+
+impl MentionUri {
+    pub fn parse(input: &str) -> Result<Self> {
+        let url = url::Url::parse(input)?;
+        let path = url.path();
+        match url.scheme() {
+            "file" => {
+                if let Some(fragment) = url.fragment() {
+                    Ok(Self::Symbol(path.into(), fragment.into()))
+                } else {
+                    Ok(Self::File(path.into()))
+                }
+            }
+            "zed" => {
+                if let Some(thread) = path.strip_prefix("/agent/thread/") {
+                    Ok(Self::Thread(acp::SessionId(thread.into())))
+                } else if let Some(rule) = path.strip_prefix("/agent/rule/") {
+                    Ok(Self::Rule(rule.into()))
+                } else {
+                    bail!("invalid zed url: {:?}", input);
+                }
+            }
+            other => bail!("unrecognized scheme {:?}", other),
+        }
+    }
+
+    pub fn name(&self) -> String {
+        match self {
+            MentionUri::File(path) => path.file_name().unwrap().to_string_lossy().into_owned(),
+            MentionUri::Symbol(_path, name) => name.clone(),
+            MentionUri::Thread(thread) => thread.to_string(),
+            MentionUri::Rule(rule) => rule.clone(),
+        }
+    }
+
+    pub fn to_link(&self) -> String {
+        let name = self.name();
+        let uri = self.to_uri();
+        format!("[{name}]({uri})")
+    }
+
+    pub fn to_uri(&self) -> String {
+        match self {
+            MentionUri::File(path) => {
+                format!("file://{}", path.display())
+            }
+            MentionUri::Symbol(path, name) => {
+                format!("file://{}#{}", path.display(), name)
+            }
+            MentionUri::Thread(thread) => {
+                format!("zed:///agent/thread/{}", thread.0)
+            }
+            MentionUri::Rule(rule) => {
+                format!("zed:///agent/rule/{}", rule)
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_mention_uri_parse_and_display() {
+        // Test file URI
+        let file_uri = "file:///path/to/file.rs";
+        let parsed = MentionUri::parse(file_uri).unwrap();
+        match &parsed {
+            MentionUri::File(path) => assert_eq!(path.to_str().unwrap(), "/path/to/file.rs"),
+            _ => panic!("Expected File variant"),
+        }
+        assert_eq!(parsed.to_uri(), file_uri);
+
+        // Test symbol URI
+        let symbol_uri = "file:///path/to/file.rs#MySymbol";
+        let parsed = MentionUri::parse(symbol_uri).unwrap();
+        match &parsed {
+            MentionUri::Symbol(path, symbol) => {
+                assert_eq!(path.to_str().unwrap(), "/path/to/file.rs");
+                assert_eq!(symbol, "MySymbol");
+            }
+            _ => panic!("Expected Symbol variant"),
+        }
+        assert_eq!(parsed.to_uri(), symbol_uri);
+
+        // Test thread URI
+        let thread_uri = "zed:///agent/thread/session123";
+        let parsed = MentionUri::parse(thread_uri).unwrap();
+        match &parsed {
+            MentionUri::Thread(session_id) => assert_eq!(session_id.0.as_ref(), "session123"),
+            _ => panic!("Expected Thread variant"),
+        }
+        assert_eq!(parsed.to_uri(), thread_uri);
+
+        // Test rule URI
+        let rule_uri = "zed:///agent/rule/my_rule";
+        let parsed = MentionUri::parse(rule_uri).unwrap();
+        match &parsed {
+            MentionUri::Rule(rule) => assert_eq!(rule, "my_rule"),
+            _ => panic!("Expected Rule variant"),
+        }
+        assert_eq!(parsed.to_uri(), rule_uri);
+
+        // Test invalid scheme
+        assert!(MentionUri::parse("http://example.com").is_err());
+
+        // Test invalid zed path
+        assert!(MentionUri::parse("zed:///invalid/path").is_err());
+    }
+}

crates/agent2/src/agent.rs

@@ -1,8 +1,8 @@
 use crate::{AgentResponseEvent, Thread, templates::Templates};
 use crate::{
     ContextServerRegistry, CopyPathTool, CreateDirectoryTool, DiagnosticsTool, EditFileTool,
-    FetchTool, FindPathTool, GrepTool, ListDirectoryTool, MovePathTool, NowTool, OpenTool,
-    ReadFileTool, TerminalTool, ThinkingTool, ToolCallAuthorization, WebSearchTool,
+    FetchTool, FindPathTool, GrepTool, ListDirectoryTool, MessageContent, MovePathTool, NowTool,
+    OpenTool, ReadFileTool, TerminalTool, ThinkingTool, ToolCallAuthorization, WebSearchTool,
 };
 use acp_thread::ModelSelector;
 use agent_client_protocol as acp;
@@ -516,10 +516,13 @@ impl acp_thread::AgentConnection for NativeAgentConnection {
                 })?;
             log::debug!("Found session for: {}", session_id);
 
-            // Convert prompt to message
-            let message = convert_prompt_to_message(params.prompt);
+            let message: Vec<MessageContent> = params
+                .prompt
+                .into_iter()
+                .map(Into::into)
+                .collect::<Vec<_>>();
             log::info!("Converted prompt to message: {} chars", message.len());
-            log::debug!("Message content: {}", message);
+            log::debug!("Message content: {:?}", message);
 
             // Get model using the ModelSelector capability (always available for agent2)
             // Get the selected model from the thread directly
@@ -623,39 +626,6 @@ impl acp_thread::AgentConnection for NativeAgentConnection {
     }
 }
 
-/// Convert ACP content blocks to a message string
-fn convert_prompt_to_message(blocks: Vec<acp::ContentBlock>) -> String {
-    log::debug!("Converting {} content blocks to message", blocks.len());
-    let mut message = String::new();
-
-    for block in blocks {
-        match block {
-            acp::ContentBlock::Text(text) => {
-                log::trace!("Processing text block: {} chars", text.text.len());
-                message.push_str(&text.text);
-            }
-            acp::ContentBlock::ResourceLink(link) => {
-                log::trace!("Processing resource link: {}", link.uri);
-                message.push_str(&format!(" @{} ", link.uri));
-            }
-            acp::ContentBlock::Image(_) => {
-                log::trace!("Processing image block");
-                message.push_str(" [image] ");
-            }
-            acp::ContentBlock::Audio(_) => {
-                log::trace!("Processing audio block");
-                message.push_str(" [audio] ");
-            }
-            acp::ContentBlock::Resource(resource) => {
-                log::trace!("Processing resource block: {:?}", resource.resource);
-                message.push_str(&format!(" [resource: {:?}] ", resource.resource));
-            }
-        }
-    }
-
-    message
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

crates/agent2/src/tests/mod.rs

@@ -1,4 +1,5 @@
 use super::*;
+use crate::MessageContent;
 use acp_thread::AgentConnection;
 use action_log::ActionLog;
 use agent_client_protocol::{self as acp};
@@ -13,8 +14,8 @@ use gpui::{
 use indoc::indoc;
 use language_model::{
     LanguageModel, LanguageModelCompletionError, LanguageModelCompletionEvent, LanguageModelId,
-    LanguageModelRegistry, LanguageModelToolResult, LanguageModelToolUse, MessageContent, Role,
-    StopReason, fake_provider::FakeLanguageModel,
+    LanguageModelRegistry, LanguageModelToolResult, LanguageModelToolUse, Role, StopReason,
+    fake_provider::FakeLanguageModel,
 };
 use project::Project;
 use prompt_store::ProjectContext;
@@ -272,14 +273,14 @@ async fn test_tool_authorization(cx: &mut TestAppContext) {
     assert_eq!(
         message.content,
         vec![
-            MessageContent::ToolResult(LanguageModelToolResult {
+            language_model::MessageContent::ToolResult(LanguageModelToolResult {
                 tool_use_id: tool_call_auth_1.tool_call.id.0.to_string().into(),
                 tool_name: ToolRequiringPermission.name().into(),
                 is_error: false,
                 content: "Allowed".into(),
                 output: Some("Allowed".into())
             }),
-            MessageContent::ToolResult(LanguageModelToolResult {
+            language_model::MessageContent::ToolResult(LanguageModelToolResult {
                 tool_use_id: tool_call_auth_2.tool_call.id.0.to_string().into(),
                 tool_name: ToolRequiringPermission.name().into(),
                 is_error: true,
@@ -312,13 +313,15 @@ async fn test_tool_authorization(cx: &mut TestAppContext) {
     let message = completion.messages.last().unwrap();
     assert_eq!(
         message.content,
-        vec![MessageContent::ToolResult(LanguageModelToolResult {
-            tool_use_id: tool_call_auth_3.tool_call.id.0.to_string().into(),
-            tool_name: ToolRequiringPermission.name().into(),
-            is_error: false,
-            content: "Allowed".into(),
-            output: Some("Allowed".into())
-        })]
+        vec![language_model::MessageContent::ToolResult(
+            LanguageModelToolResult {
+                tool_use_id: tool_call_auth_3.tool_call.id.0.to_string().into(),
+                tool_name: ToolRequiringPermission.name().into(),
+                is_error: false,
+                content: "Allowed".into(),
+                output: Some("Allowed".into())
+            }
+        )]
     );
 
     // Simulate a final tool call, ensuring we don't trigger authorization.
@@ -337,13 +340,15 @@ async fn test_tool_authorization(cx: &mut TestAppContext) {
     let message = completion.messages.last().unwrap();
     assert_eq!(
         message.content,
-        vec![MessageContent::ToolResult(LanguageModelToolResult {
-            tool_use_id: "tool_id_4".into(),
-            tool_name: ToolRequiringPermission.name().into(),
-            is_error: false,
-            content: "Allowed".into(),
-            output: Some("Allowed".into())
-        })]
+        vec![language_model::MessageContent::ToolResult(
+            LanguageModelToolResult {
+                tool_use_id: "tool_id_4".into(),
+                tool_name: ToolRequiringPermission.name().into(),
+                is_error: false,
+                content: "Allowed".into(),
+                output: Some("Allowed".into())
+            }
+        )]
     );
 }
 

crates/agent2/src/thread.rs

@@ -1,4 +1,5 @@
 use crate::{ContextServerRegistry, SystemPromptTemplate, Template, Templates};
+use acp_thread::MentionUri;
 use action_log::ActionLog;
 use agent_client_protocol as acp;
 use agent_settings::{AgentProfileId, AgentSettings};
@@ -13,10 +14,10 @@ use futures::{
 };
 use gpui::{App, Context, Entity, SharedString, Task};
 use language_model::{
-    LanguageModel, LanguageModelCompletionError, LanguageModelCompletionEvent,
+    LanguageModel, LanguageModelCompletionError, LanguageModelCompletionEvent, LanguageModelImage,
     LanguageModelRequest, LanguageModelRequestMessage, LanguageModelRequestTool,
     LanguageModelToolResult, LanguageModelToolResultContent, LanguageModelToolSchemaFormat,
-    LanguageModelToolUse, LanguageModelToolUseId, MessageContent, Role, StopReason,
+    LanguageModelToolUse, LanguageModelToolUseId, Role, StopReason,
 };
 use log;
 use project::Project;
@@ -25,7 +26,8 @@ use schemars::{JsonSchema, Schema};
 use serde::{Deserialize, Serialize};
 use settings::{Settings, update_settings_file};
 use smol::stream::StreamExt;
-use std::{cell::RefCell, collections::BTreeMap, fmt::Write, rc::Rc, sync::Arc};
+use std::fmt::Write;
+use std::{cell::RefCell, collections::BTreeMap, path::Path, rc::Rc, sync::Arc};
 use util::{ResultExt, markdown::MarkdownCodeBlock};
 
 #[derive(Debug, Clone)]
@@ -34,6 +36,23 @@ pub struct AgentMessage {
     pub content: Vec<MessageContent>,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum MessageContent {
+    Text(String),
+    Thinking {
+        text: String,
+        signature: Option<String>,
+    },
+    Mention {
+        uri: MentionUri,
+        content: String,
+    },
+    RedactedThinking(String),
+    Image(LanguageModelImage),
+    ToolUse(LanguageModelToolUse),
+    ToolResult(LanguageModelToolResult),
+}
+
 impl AgentMessage {
     pub fn to_markdown(&self) -> String {
         let mut markdown = format!("## {}\n", self.role);
@@ -93,6 +112,9 @@ impl AgentMessage {
                         .unwrap();
                     }
                 }
+                MessageContent::Mention { uri, .. } => {
+                    write!(markdown, "{}", uri.to_link()).ok();
+                }
             }
         }
 
@@ -214,10 +236,11 @@ impl Thread {
     /// The returned channel will report all the occurrences in which the model stops before erroring or ending its turn.
     pub fn send(
         &mut self,
-        content: impl Into<MessageContent>,
+        content: impl Into<UserMessage>,
         cx: &mut Context<Self>,
     ) -> mpsc::UnboundedReceiver<Result<AgentResponseEvent, LanguageModelCompletionError>> {
-        let content = content.into();
+        let content = content.into().0;
+
         let model = self.selected_model.clone();
         log::info!("Thread::send called with model: {:?}", model.name());
         log::debug!("Thread::send content: {:?}", content);
@@ -230,7 +253,7 @@ impl Thread {
         let user_message_ix = self.messages.len();
         self.messages.push(AgentMessage {
             role: Role::User,
-            content: vec![content],
+            content,
         });
         log::info!("Total messages in thread: {}", self.messages.len());
         self.running_turn = Some(cx.spawn(async move |thread, cx| {
@@ -353,7 +376,7 @@ impl Thread {
         log::debug!("System message built");
         AgentMessage {
             role: Role::System,
-            content: vec![prompt.into()],
+            content: vec![prompt.as_str().into()],
         }
     }
 
@@ -701,11 +724,7 @@ impl Thread {
                     },
                     message.content.len()
                 );
-                LanguageModelRequestMessage {
-                    role: message.role,
-                    content: message.content.clone(),
-                    cache: false,
-                }
+                message.to_request()
             })
             .collect();
         messages
@@ -720,6 +739,20 @@ impl Thread {
     }
 }
 
+pub struct UserMessage(Vec<MessageContent>);
+
+impl From<Vec<MessageContent>> for UserMessage {
+    fn from(content: Vec<MessageContent>) -> Self {
+        UserMessage(content)
+    }
+}
+
+impl<T: Into<MessageContent>> From<T> for UserMessage {
+    fn from(content: T) -> Self {
+        UserMessage(vec![content.into()])
+    }
+}
+
 pub trait AgentTool
 where
     Self: 'static + Sized,
@@ -1102,3 +1135,207 @@ impl std::ops::DerefMut for ToolCallEventStreamReceiver {
         &mut self.0
     }
 }
+
+impl AgentMessage {
+    fn to_request(&self) -> language_model::LanguageModelRequestMessage {
+        let mut message = LanguageModelRequestMessage {
+            role: self.role,
+            content: Vec::with_capacity(self.content.len()),
+            cache: false,
+        };
+
+        const OPEN_CONTEXT: &str = "<context>\n\
+            The following items were attached by the user. \
+            They are up-to-date and don't need to be re-read.\n\n";
+
+        const OPEN_FILES_TAG: &str = "<files>";
+        const OPEN_SYMBOLS_TAG: &str = "<symbols>";
+        const OPEN_THREADS_TAG: &str = "<threads>";
+        const OPEN_RULES_TAG: &str =
+            "<rules>\nThe user has specified the following rules that should be applied:\n";
+
+        let mut file_context = OPEN_FILES_TAG.to_string();
+        let mut symbol_context = OPEN_SYMBOLS_TAG.to_string();
+        let mut thread_context = OPEN_THREADS_TAG.to_string();
+        let mut rules_context = OPEN_RULES_TAG.to_string();
+
+        for chunk in &self.content {
+            let chunk = match chunk {
+                MessageContent::Text(text) => language_model::MessageContent::Text(text.clone()),
+                MessageContent::Thinking { text, signature } => {
+                    language_model::MessageContent::Thinking {
+                        text: text.clone(),
+                        signature: signature.clone(),
+                    }
+                }
+                MessageContent::RedactedThinking(value) => {
+                    language_model::MessageContent::RedactedThinking(value.clone())
+                }
+                MessageContent::ToolUse(value) => {
+                    language_model::MessageContent::ToolUse(value.clone())
+                }
+                MessageContent::ToolResult(value) => {
+                    language_model::MessageContent::ToolResult(value.clone())
+                }
+                MessageContent::Image(value) => {
+                    language_model::MessageContent::Image(value.clone())
+                }
+                MessageContent::Mention { uri, content } => {
+                    match uri {
+                        MentionUri::File(path) | MentionUri::Symbol(path, _) => {
+                            write!(
+                                &mut symbol_context,
+                                "\n{}",
+                                MarkdownCodeBlock {
+                                    tag: &codeblock_tag(&path),
+                                    text: &content.to_string(),
+                                }
+                            )
+                            .ok();
+                        }
+                        MentionUri::Thread(_session_id) => {
+                            write!(&mut thread_context, "\n{}\n", content).ok();
+                        }
+                        MentionUri::Rule(_user_prompt_id) => {
+                            write!(
+                                &mut rules_context,
+                                "\n{}",
+                                MarkdownCodeBlock {
+                                    tag: "",
+                                    text: &content
+                                }
+                            )
+                            .ok();
+                        }
+                    }
+
+                    language_model::MessageContent::Text(uri.to_link())
+                }
+            };
+
+            message.content.push(chunk);
+        }
+
+        let len_before_context = message.content.len();
+
+        if file_context.len() > OPEN_FILES_TAG.len() {
+            file_context.push_str("</files>\n");
+            message
+                .content
+                .push(language_model::MessageContent::Text(file_context));
+        }
+
+        if symbol_context.len() > OPEN_SYMBOLS_TAG.len() {
+            symbol_context.push_str("</symbols>\n");
+            message
+                .content
+                .push(language_model::MessageContent::Text(symbol_context));
+        }
+
+        if thread_context.len() > OPEN_THREADS_TAG.len() {
+            thread_context.push_str("</threads>\n");
+            message
+                .content
+                .push(language_model::MessageContent::Text(thread_context));
+        }
+
+        if rules_context.len() > OPEN_RULES_TAG.len() {
+            rules_context.push_str("</user_rules>\n");
+            message
+                .content
+                .push(language_model::MessageContent::Text(rules_context));
+        }
+
+        if message.content.len() > len_before_context {
+            message.content.insert(
+                len_before_context,
+                language_model::MessageContent::Text(OPEN_CONTEXT.into()),
+            );
+            message
+                .content
+                .push(language_model::MessageContent::Text("</context>".into()));
+        }
+
+        message
+    }
+}
+
+fn codeblock_tag(full_path: &Path) -> String {
+    let mut result = String::new();
+
+    if let Some(extension) = full_path.extension().and_then(|ext| ext.to_str()) {
+        let _ = write!(result, "{} ", extension);
+    }
+
+    let _ = write!(result, "{}", full_path.display());
+
+    result
+}
+
+impl From<acp::ContentBlock> for MessageContent {
+    fn from(value: acp::ContentBlock) -> Self {
+        match value {
+            acp::ContentBlock::Text(text_content) => MessageContent::Text(text_content.text),
+            acp::ContentBlock::Image(image_content) => {
+                MessageContent::Image(convert_image(image_content))
+            }
+            acp::ContentBlock::Audio(_) => {
+                // TODO
+                MessageContent::Text("[audio]".to_string())
+            }
+            acp::ContentBlock::ResourceLink(resource_link) => {
+                match MentionUri::parse(&resource_link.uri) {
+                    Ok(uri) => Self::Mention {
+                        uri,
+                        content: String::new(),
+                    },
+                    Err(err) => {
+                        log::error!("Failed to parse mention link: {}", err);
+                        MessageContent::Text(format!(
+                            "[{}]({})",
+                            resource_link.name, resource_link.uri
+                        ))
+                    }
+                }
+            }
+            acp::ContentBlock::Resource(resource) => match resource.resource {
+                acp::EmbeddedResourceResource::TextResourceContents(resource) => {
+                    match MentionUri::parse(&resource.uri) {
+                        Ok(uri) => Self::Mention {
+                            uri,
+                            content: resource.text,
+                        },
+                        Err(err) => {
+                            log::error!("Failed to parse mention link: {}", err);
+                            MessageContent::Text(
+                                MarkdownCodeBlock {
+                                    tag: &resource.uri,
+                                    text: &resource.text,
+                                }
+                                .to_string(),
+                            )
+                        }
+                    }
+                }
+                acp::EmbeddedResourceResource::BlobResourceContents(_) => {
+                    // TODO
+                    MessageContent::Text("[blob]".to_string())
+                }
+            },
+        }
+    }
+}
+
+fn convert_image(image_content: acp::ImageContent) -> LanguageModelImage {
+    LanguageModelImage {
+        source: image_content.data.into(),
+        // TODO: make this optional?
+        size: gpui::Size::new(0.into(), 0.into()),
+    }
+}
+
+impl From<&str> for MessageContent {
+    fn from(text: &str) -> Self {
+        MessageContent::Text(text.into())
+    }
+}

crates/agent_ui/src/acp/completion_provider.rs

@@ -1,18 +1,20 @@
 use std::ops::Range;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 
-use anyhow::Result;
+use acp_thread::MentionUri;
+use anyhow::{Context as _, Result};
 use collections::HashMap;
 use editor::display_map::CreaseId;
 use editor::{CompletionProvider, Editor, ExcerptId};
 use file_icons::FileIcons;
+use futures::future::try_join_all;
 use gpui::{App, Entity, Task, WeakEntity};
 use language::{Buffer, CodeLabel, HighlightId};
 use lsp::CompletionContext;
 use parking_lot::Mutex;
-use project::{Completion, CompletionIntent, CompletionResponse, ProjectPath, WorktreeId};
+use project::{Completion, CompletionIntent, CompletionResponse, Project, ProjectPath, WorktreeId};
 use rope::Point;
 use text::{Anchor, ToPoint};
 use ui::prelude::*;
@@ -23,21 +25,63 @@ use crate::context_picker::file_context_picker::{extract_file_name_and_directory
 
 #[derive(Default)]
 pub struct MentionSet {
-    paths_by_crease_id: HashMap<CreaseId, ProjectPath>,
+    paths_by_crease_id: HashMap<CreaseId, MentionUri>,
 }
 
 impl MentionSet {
-    pub fn insert(&mut self, crease_id: CreaseId, path: ProjectPath) {
-        self.paths_by_crease_id.insert(crease_id, path);
-    }
-
-    pub fn path_for_crease_id(&self, crease_id: CreaseId) -> Option<ProjectPath> {
-        self.paths_by_crease_id.get(&crease_id).cloned()
+    pub fn insert(&mut self, crease_id: CreaseId, path: PathBuf) {
+        self.paths_by_crease_id
+            .insert(crease_id, MentionUri::File(path));
     }
 
     pub fn drain(&mut self) -> impl Iterator<Item = CreaseId> {
         self.paths_by_crease_id.drain().map(|(id, _)| id)
     }
+
+    pub fn contents(
+        &self,
+        project: Entity<Project>,
+        cx: &mut App,
+    ) -> Task<Result<HashMap<CreaseId, Mention>>> {
+        let contents = self
+            .paths_by_crease_id
+            .iter()
+            .map(|(crease_id, uri)| match uri {
+                MentionUri::File(path) => {
+                    let crease_id = *crease_id;
+                    let uri = uri.clone();
+                    let path = path.to_path_buf();
+                    let buffer_task = project.update(cx, |project, cx| {
+                        let path = project
+                            .find_project_path(path, cx)
+                            .context("Failed to find project path")?;
+                        anyhow::Ok(project.open_buffer(path, cx))
+                    });
+
+                    cx.spawn(async move |cx| {
+                        let buffer = buffer_task?.await?;
+                        let content = buffer.read_with(cx, |buffer, _cx| buffer.text())?;
+
+                        anyhow::Ok((crease_id, Mention { uri, content }))
+                    })
+                }
+                _ => {
+                    // TODO
+                    unimplemented!()
+                }
+            })
+            .collect::<Vec<_>>();
+
+        cx.spawn(async move |_cx| {
+            let contents = try_join_all(contents).await?.into_iter().collect();
+            anyhow::Ok(contents)
+        })
+    }
+}
+
+pub struct Mention {
+    pub uri: MentionUri,
+    pub content: String,
 }
 
 pub struct ContextPickerCompletionProvider {
@@ -68,6 +112,7 @@ impl ContextPickerCompletionProvider {
         source_range: Range<Anchor>,
         editor: Entity<Editor>,
         mention_set: Arc<Mutex<MentionSet>>,
+        project: Entity<Project>,
         cx: &App,
     ) -> Completion {
         let (file_name, directory) =
@@ -112,6 +157,7 @@ impl ContextPickerCompletionProvider {
                 new_text_len - 1,
                 editor,
                 mention_set,
+                project,
             )),
         }
     }
@@ -159,6 +205,7 @@ impl CompletionProvider for ContextPickerCompletionProvider {
             return Task::ready(Ok(Vec::new()));
         };
 
+        let project = workspace.read(cx).project().clone();
         let snapshot = buffer.read(cx).snapshot();
         let source_range = snapshot.anchor_before(state.source_range.start)
             ..snapshot.anchor_after(state.source_range.end);
@@ -195,6 +242,7 @@ impl CompletionProvider for ContextPickerCompletionProvider {
                             source_range.clone(),
                             editor.clone(),
                             mention_set.clone(),
+                            project.clone(),
                             cx,
                         )
                     })
@@ -254,6 +302,7 @@ fn confirm_completion_callback(
     content_len: usize,
     editor: Entity<Editor>,
     mention_set: Arc<Mutex<MentionSet>>,
+    project: Entity<Project>,
 ) -> Arc<dyn Fn(CompletionIntent, &mut Window, &mut App) -> bool + Send + Sync> {
     Arc::new(move |_, window, cx| {
         let crease_text = crease_text.clone();
@@ -261,6 +310,7 @@ fn confirm_completion_callback(
         let editor = editor.clone();
         let project_path = project_path.clone();
         let mention_set = mention_set.clone();
+        let project = project.clone();
         window.defer(cx, move |window, cx| {
             let crease_id = crate::context_picker::insert_crease_for_mention(
                 excerpt_id,
@@ -272,8 +322,13 @@ fn confirm_completion_callback(
                 window,
                 cx,
             );
+
+            let Some(path) = project.read(cx).absolute_path(&project_path, cx) else {
+                return;
+            };
+
             if let Some(crease_id) = crease_id {
-                mention_set.lock().insert(crease_id, project_path);
+                mention_set.lock().insert(crease_id, path);
             }
         });
         false

crates/agent_ui/src/acp/thread_view.rs

@@ -1,6 +1,6 @@
 use acp_thread::{
     AcpThread, AcpThreadEvent, AgentThreadEntry, AssistantMessage, AssistantMessageChunk,
-    LoadError, MentionPath, ThreadStatus, ToolCall, ToolCallContent, ToolCallStatus,
+    LoadError, MentionUri, ThreadStatus, ToolCall, ToolCallContent, ToolCallStatus,
 };
 use acp_thread::{AgentConnection, Plan};
 use action_log::ActionLog;
@@ -28,6 +28,7 @@ use markdown::{HeadingLevelStyles, Markdown, MarkdownElement, MarkdownStyle};
 use parking_lot::Mutex;
 use project::{CompletionIntent, Project};
 use settings::{Settings as _, SettingsStore};
+use std::path::PathBuf;
 use std::{
     cell::RefCell, collections::BTreeMap, path::Path, process::ExitStatus, rc::Rc, sync::Arc,
     time::Duration,
@@ -376,81 +377,101 @@ impl AcpThreadView {
         let mut ix = 0;
         let mut chunks: Vec<acp::ContentBlock> = Vec::new();
         let project = self.project.clone();
-        self.message_editor.update(cx, |editor, cx| {
-            let text = editor.text(cx);
-            editor.display_map.update(cx, |map, cx| {
-                let snapshot = map.snapshot(cx);
-                for (crease_id, crease) in snapshot.crease_snapshot.creases() {
-                    // Skip creases that have been edited out of the message buffer.
-                    if !crease.range().start.is_valid(&snapshot.buffer_snapshot) {
-                        continue;
-                    }
 
-                    if let Some(project_path) =
-                        self.mention_set.lock().path_for_crease_id(crease_id)
-                    {
-                        let crease_range = crease.range().to_offset(&snapshot.buffer_snapshot);
-                        if crease_range.start > ix {
-                            chunks.push(text[ix..crease_range.start].into());
+        let contents = self.mention_set.lock().contents(project, cx);
+
+        cx.spawn_in(window, async move |this, cx| {
+            let contents = match contents.await {
+                Ok(contents) => contents,
+                Err(e) => {
+                    this.update(cx, |this, cx| {
+                        this.last_error =
+                            Some(cx.new(|cx| Markdown::new(e.to_string().into(), None, None, cx)));
+                    })
+                    .ok();
+                    return;
+                }
+            };
+
+            this.update_in(cx, |this, window, cx| {
+                this.message_editor.update(cx, |editor, cx| {
+                    let text = editor.text(cx);
+                    editor.display_map.update(cx, |map, cx| {
+                        let snapshot = map.snapshot(cx);
+                        for (crease_id, crease) in snapshot.crease_snapshot.creases() {
+                            // Skip creases that have been edited out of the message buffer.
+                            if !crease.range().start.is_valid(&snapshot.buffer_snapshot) {
+                                continue;
+                            }
+
+                            if let Some(mention) = contents.get(&crease_id) {
+                                let crease_range =
+                                    crease.range().to_offset(&snapshot.buffer_snapshot);
+                                if crease_range.start > ix {
+                                    chunks.push(text[ix..crease_range.start].into());
+                                }
+                                chunks.push(acp::ContentBlock::Resource(acp::EmbeddedResource {
+                                    annotations: None,
+                                    resource: acp::EmbeddedResourceResource::TextResourceContents(
+                                        acp::TextResourceContents {
+                                            mime_type: None,
+                                            text: mention.content.clone(),
+                                            uri: mention.uri.to_uri(),
+                                        },
+                                    ),
+                                }));
+                                ix = crease_range.end;
+                            }
                         }
-                        if let Some(abs_path) = project.read(cx).absolute_path(&project_path, cx) {
-                            let path_str = abs_path.display().to_string();
-                            chunks.push(acp::ContentBlock::ResourceLink(acp::ResourceLink {
-                                uri: path_str.clone(),
-                                name: path_str,
-                                annotations: None,
-                                description: None,
-                                mime_type: None,
-                                size: None,
-                                title: None,
-                            }));
+
+                        if ix < text.len() {
+                            let last_chunk = text[ix..].trim_end();
+                            if !last_chunk.is_empty() {
+                                chunks.push(last_chunk.into());
+                            }
                         }
-                        ix = crease_range.end;
-                    }
+                    })
+                });
+
+                if chunks.is_empty() {
+                    return;
                 }
 
-                if ix < text.len() {
-                    let last_chunk = text[ix..].trim_end();
-                    if !last_chunk.is_empty() {
-                        chunks.push(last_chunk.into());
-                    }
-                }
-            })
-        });
-
-        if chunks.is_empty() {
-            return;
-        }
-
-        let Some(thread) = self.thread() else {
-            return;
-        };
-        let task = thread.update(cx, |thread, cx| thread.send(chunks.clone(), cx));
-
-        cx.spawn(async move |this, cx| {
-            let result = task.await;
-
-            this.update(cx, |this, cx| {
-                if let Err(err) = result {
-                    this.last_error =
-                        Some(cx.new(|cx| Markdown::new(err.to_string().into(), None, None, cx)))
-                }
+                let Some(thread) = this.thread() else {
+                    return;
+                };
+                let task = thread.update(cx, |thread, cx| thread.send(chunks.clone(), cx));
+
+                cx.spawn(async move |this, cx| {
+                    let result = task.await;
+
+                    this.update(cx, |this, cx| {
+                        if let Err(err) = result {
+                            this.last_error =
+                                Some(cx.new(|cx| {
+                                    Markdown::new(err.to_string().into(), None, None, cx)
+                                }))
+                        }
+                    })
+                })
+                .detach();
+
+                let mention_set = this.mention_set.clone();
+
+                this.set_editor_is_expanded(false, cx);
+
+                this.message_editor.update(cx, |editor, cx| {
+                    editor.clear(window, cx);
+                    editor.remove_creases(mention_set.lock().drain(), cx)
+                });
+
+                this.scroll_to_bottom(cx);
+
+                this.message_history.borrow_mut().push(chunks);
             })
+            .ok();
         })
         .detach();
-
-        let mention_set = self.mention_set.clone();
-
-        self.set_editor_is_expanded(false, cx);
-
-        self.message_editor.update(cx, |editor, cx| {
-            editor.clear(window, cx);
-            editor.remove_creases(mention_set.lock().drain(), cx)
-        });
-
-        self.scroll_to_bottom(cx);
-
-        self.message_history.borrow_mut().push(chunks);
     }
 
     fn previous_history_message(
@@ -563,16 +584,19 @@ impl AcpThreadView {
                 acp::ContentBlock::Text(text_content) => {
                     text.push_str(&text_content.text);
                 }
-                acp::ContentBlock::ResourceLink(resource_link) => {
-                    let path = Path::new(&resource_link.uri);
+                acp::ContentBlock::Resource(acp::EmbeddedResource {
+                    resource: acp::EmbeddedResourceResource::TextResourceContents(resource),
+                    ..
+                }) => {
+                    let path = PathBuf::from(&resource.uri);
+                    let project_path = project.read(cx).project_path_for_absolute_path(&path, cx);
                     let start = text.len();
-                    let content = MentionPath::new(&path).to_string();
+                    let content = MentionUri::File(path).to_uri();
                     text.push_str(&content);
                     let end = text.len();
-                    if let Some(project_path) =
-                        project.read(cx).project_path_for_absolute_path(&path, cx)
-                    {
-                        let filename: SharedString = path
+                    if let Some(project_path) = project_path {
+                        let filename: SharedString = project_path
+                            .path
                             .file_name()
                             .unwrap_or_default()
                             .to_string_lossy()
@@ -583,7 +607,8 @@ impl AcpThreadView {
                 }
                 acp::ContentBlock::Image(_)
                 | acp::ContentBlock::Audio(_)
-                | acp::ContentBlock::Resource(_) => {}
+                | acp::ContentBlock::Resource(_)
+                | acp::ContentBlock::ResourceLink(_) => {}
             }
         }
 
@@ -602,18 +627,21 @@ impl AcpThreadView {
             };
 
             let anchor = snapshot.anchor_before(range.start);
-            let crease_id = crate::context_picker::insert_crease_for_mention(
-                anchor.excerpt_id,
-                anchor.text_anchor,
-                range.end - range.start,
-                filename,
-                crease_icon_path,
-                message_editor.clone(),
-                window,
-                cx,
-            );
-            if let Some(crease_id) = crease_id {
-                mention_set.lock().insert(crease_id, project_path);
+            if let Some(project_path) = project.read(cx).absolute_path(&project_path, cx) {
+                let crease_id = crate::context_picker::insert_crease_for_mention(
+                    anchor.excerpt_id,
+                    anchor.text_anchor,
+                    range.end - range.start,
+                    filename,
+                    crease_icon_path,
+                    message_editor.clone(),
+                    window,
+                    cx,
+                );
+
+                if let Some(crease_id) = crease_id {
+                    mention_set.lock().insert(crease_id, project_path);
+                }
             }
         }
 
@@ -2562,25 +2590,31 @@ impl AcpThreadView {
             return;
         };
 
-        if let Some(mention_path) = MentionPath::try_parse(&url) {
-            workspace.update(cx, |workspace, cx| {
-                let project = workspace.project();
-                let Some((path, entry)) = project.update(cx, |project, cx| {
-                    let path = project.find_project_path(mention_path.path(), cx)?;
-                    let entry = project.entry_for_path(&path, cx)?;
-                    Some((path, entry))
-                }) else {
-                    return;
-                };
+        if let Some(mention) = MentionUri::parse(&url).log_err() {
+            workspace.update(cx, |workspace, cx| match mention {
+                MentionUri::File(path) => {
+                    let project = workspace.project();
+                    let Some((path, entry)) = project.update(cx, |project, cx| {
+                        let path = project.find_project_path(path, cx)?;
+                        let entry = project.entry_for_path(&path, cx)?;
+                        Some((path, entry))
+                    }) else {
+                        return;
+                    };
 
-                if entry.is_dir() {
-                    project.update(cx, |_, cx| {
-                        cx.emit(project::Event::RevealInProjectPanel(entry.id));
-                    });
-                } else {
-                    workspace
-                        .open_path(path, None, true, window, cx)
-                        .detach_and_log_err(cx);
+                    if entry.is_dir() {
+                        project.update(cx, |_, cx| {
+                            cx.emit(project::Event::RevealInProjectPanel(entry.id));
+                        });
+                    } else {
+                        workspace
+                            .open_path(path, None, true, window, cx)
+                            .detach_and_log_err(cx);
+                    }
+                }
+                _ => {
+                    // TODO
+                    unimplemented!()
                 }
             })
         } else {
@@ -2975,6 +3009,7 @@ impl AcpThreadView {
                 anchor..anchor,
                 self.message_editor.clone(),
                 self.mention_set.clone(),
+                self.project.clone(),
                 cx,
             );
 
@@ -3117,7 +3152,7 @@ fn user_message_markdown_style(window: &Window, cx: &App) -> MarkdownStyle {
 
     style.base_text_style = text_style;
     style.link_callback = Some(Rc::new(move |url, cx| {
-        if MentionPath::try_parse(url).is_some() {
+        if MentionUri::parse(url).is_ok() {
             let colors = cx.theme().colors();
             Some(TextStyleRefinement {
                 background_color: Some(colors.element_background),