use acp_thread::SUBAGENT_SESSION_ID_META_KEY;use agent_client_protocol as acp;use anyhow::Result;use gpui::{App, SharedString, Task, WeakEntity};use language_model::LanguageModelToolResultContent;use schemars::JsonSchema;use serde::{Deserialize, Serialize};use std::rc::Rc;use std::sync::Arc; use crate::{AgentTool, Thread, ThreadEnvironment, ToolCallEventStream, ToolInput}; /// Spawns an agent to perform a delegated task.////// Use this tool when you want to:/// - Run multiple tasks in parallel./// - Delegate a self-contained task where you only need the final outcome.////// You will receive only the agent's final message as output.////// **New session** (no session_id): Creates a new agent that does NOT see your conversation history. Include all relevant context (file paths, requirements, constraints) in the message.////// **Follow-up** (with session_id): Sends a follow-up to an existing agent session. The agent already has full context, so send only a short, direct message — do NOT repeat the original task or context. Examples: "Also update the tests", "Fix the compile error in foo.rs", "Retry".////// - If spawning multiple agents that might write to the filesystem, provide guidance on how to avoid conflicts (e.g. assign each to different directories).#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]pub struct SpawnAgentToolInput { /// Short label displayed in the UI while the agent runs (e.g., "Researching alternatives") pub label: String, /// The prompt for the agent. For new sessions, include full context needed for the task. For follow-ups (with session_id), you can rely on the agent already having the previous message. pub message: String, /// Session ID of an existing agent session to continue instead of creating a new one. #[serde(default)] pub session_id: Option<acp::SessionId>,} #[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]#[serde(untagged)]pub enum SpawnAgentToolOutput { Success { session_id: acp::SessionId, output: String, }, Error { #[serde(skip_serializing_if = "Option::is_none")] #[serde(default)] session_id: Option<acp::SessionId>, error: String, },} impl From<SpawnAgentToolOutput> for LanguageModelToolResultContent { fn from(output: SpawnAgentToolOutput) -> Self { serde_json::to_string(&output) .unwrap_or_else(|e| format!("Failed to serialize spawn_agent output: {e}")) .into() }} /// Tool that spawns an agent thread to work on a task.pub struct SpawnAgentTool { parent_thread: WeakEntity<Thread>, environment: Rc<dyn ThreadEnvironment>,} impl SpawnAgentTool { pub fn new(parent_thread: WeakEntity<Thread>, environment: Rc<dyn ThreadEnvironment>) -> Self { Self { parent_thread, environment, } }} impl AgentTool for SpawnAgentTool { type Input = SpawnAgentToolInput; type Output = SpawnAgentToolOutput; const NAME: &'static str = "spawn_agent"; fn kind() -> acp::ToolKind { acp::ToolKind::Other } fn initial_title( &self, input: Result<Self::Input, serde_json::Value>, _cx: &mut App, ) -> SharedString { input .map(|i| i.label.into()) .unwrap_or_else(|_| "Spawning agent".into()) } fn run( self: Arc<Self>, input: ToolInput<Self::Input>, event_stream: ToolCallEventStream, cx: &mut App, ) -> Task<Result<Self::Output, Self::Output>> { cx.spawn(async move |cx| { let input = input .recv() .await .map_err(|e| SpawnAgentToolOutput::Error { session_id: None, error: format!("Failed to receive tool input: {e}"), })?; let (subagent, subagent_session_id) = cx.update(|cx| { let Some(parent_thread_entity) = self.parent_thread.upgrade() else { return Err(SpawnAgentToolOutput::Error { session_id: None, error: "Parent thread no longer exists".to_string(), }); }; let subagent = if let Some(session_id) = input.session_id { self.environment.resume_subagent( parent_thread_entity, session_id, input.message, cx, ) } else { self.environment.create_subagent( parent_thread_entity, input.label, input.message, cx, ) }; let subagent = subagent.map_err(|err| SpawnAgentToolOutput::Error { session_id: None, error: err.to_string(), })?; let subagent_session_id = subagent.id(); event_stream.subagent_spawned(subagent_session_id.clone()); let meta = acp::Meta::from_iter([( SUBAGENT_SESSION_ID_META_KEY.into(), subagent_session_id.to_string().into(), )]); event_stream.update_fields_with_meta(acp::ToolCallUpdateFields::new(), Some(meta)); Ok((subagent, subagent_session_id)) })?; match subagent.wait_for_output(cx).await { Ok(output) => { event_stream.update_fields( acp::ToolCallUpdateFields::new().content(vec![output.clone().into()]), ); Ok(SpawnAgentToolOutput::Success { session_id: subagent_session_id, output, }) } Err(e) => { let error = e.to_string(); event_stream.update_fields( acp::ToolCallUpdateFields::new().content(vec![error.clone().into()]), ); Err(SpawnAgentToolOutput::Error { session_id: Some(subagent_session_id), error, }) } } }) } fn replay( &self, _input: Self::Input, output: Self::Output, event_stream: ToolCallEventStream, _cx: &mut App, ) -> Result<()> { let session_id = match &output { SpawnAgentToolOutput::Success { session_id, .. } => Some(session_id), SpawnAgentToolOutput::Error { session_id, .. } => session_id.as_ref(), }; if let Some(session_id) = session_id { event_stream.subagent_spawned(session_id.clone()); let meta = acp::Meta::from_iter([( SUBAGENT_SESSION_ID_META_KEY.into(), session_id.to_string().into(), )]); event_stream.update_fields_with_meta(acp::ToolCallUpdateFields::new(), Some(meta)); } let content = match &output { SpawnAgentToolOutput::Success { output, .. } => output.into(), SpawnAgentToolOutput::Error { error, .. } => error.into(), }; event_stream.update_fields(acp::ToolCallUpdateFields::new().content(vec![content])); Ok(()) }}
use acp_thread::SUBAGENT_SESSION_ID_META_KEY;
use agent_client_protocol as acp;
use anyhow::Result;
use gpui::{App, SharedString, Task, WeakEntity};
use language_model::LanguageModelToolResultContent;
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};
use std::rc::Rc;
use std::sync::Arc;
use crate::{AgentTool, Thread, ThreadEnvironment, ToolCallEventStream, ToolInput};
/// Spawns an agent to perform a delegated task.
///
/// Use this tool when you want to:
/// - Run multiple tasks in parallel.
/// - Delegate a self-contained task where you only need the final outcome.
///
/// You will receive only the agent's final message as output.
///
/// **New session** (no session_id): Creates a new agent that does NOT see your conversation history. Include all relevant context (file paths, requirements, constraints) in the message.
///
/// **Follow-up** (with session_id): Sends a follow-up to an existing agent session. The agent already has full context, so send only a short, direct message — do NOT repeat the original task or context. Examples: "Also update the tests", "Fix the compile error in foo.rs", "Retry".
///
/// - If spawning multiple agents that might write to the filesystem, provide guidance on how to avoid conflicts (e.g. assign each to different directories).
#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
pub struct SpawnAgentToolInput {
/// Short label displayed in the UI while the agent runs (e.g., "Researching alternatives")
pub label: String,
/// The prompt for the agent. For new sessions, include full context needed for the task. For follow-ups (with session_id), you can rely on the agent already having the previous message.
pub message: String,
/// Session ID of an existing agent session to continue instead of creating a new one.
#[serde(default)]
pub session_id: Option<acp::SessionId>,
}
#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
#[serde(untagged)]
pub enum SpawnAgentToolOutput {
Success {
session_id: acp::SessionId,
output: String,
},
Error {
#[serde(skip_serializing_if = "Option::is_none")]
#[serde(default)]
session_id: Option<acp::SessionId>,
error: String,
},
}
impl From<SpawnAgentToolOutput> for LanguageModelToolResultContent {
fn from(output: SpawnAgentToolOutput) -> Self {
serde_json::to_string(&output)
.unwrap_or_else(|e| format!("Failed to serialize spawn_agent output: {e}"))
.into()
}
}
/// Tool that spawns an agent thread to work on a task.
pub struct SpawnAgentTool {
parent_thread: WeakEntity<Thread>,
environment: Rc<dyn ThreadEnvironment>,
}
impl SpawnAgentTool {
pub fn new(parent_thread: WeakEntity<Thread>, environment: Rc<dyn ThreadEnvironment>) -> Self {
Self {
parent_thread,
environment,
}
}
}
impl AgentTool for SpawnAgentTool {
type Input = SpawnAgentToolInput;
type Output = SpawnAgentToolOutput;
const NAME: &'static str = "spawn_agent";
fn kind() -> acp::ToolKind {
acp::ToolKind::Other
}
fn initial_title(
&self,
input: Result<Self::Input, serde_json::Value>,
_cx: &mut App,
) -> SharedString {
input
.map(|i| i.label.into())
.unwrap_or_else(|_| "Spawning agent".into())
}
fn run(
self: Arc<Self>,
input: ToolInput<Self::Input>,
event_stream: ToolCallEventStream,
cx: &mut App,
) -> Task<Result<Self::Output, Self::Output>> {
cx.spawn(async move |cx| {
let input = input
.recv()
.await
.map_err(|e| SpawnAgentToolOutput::Error {
session_id: None,
error: format!("Failed to receive tool input: {e}"),
})?;
let (subagent, subagent_session_id) = cx.update(|cx| {
let Some(parent_thread_entity) = self.parent_thread.upgrade() else {
return Err(SpawnAgentToolOutput::Error {
session_id: None,
error: "Parent thread no longer exists".to_string(),
});
};
let subagent = if let Some(session_id) = input.session_id {
self.environment.resume_subagent(
parent_thread_entity,
session_id,
input.message,
cx,
)
} else {
self.environment.create_subagent(
parent_thread_entity,
input.label,
input.message,
cx,
)
};
let subagent = subagent.map_err(|err| SpawnAgentToolOutput::Error {
session_id: None,
error: err.to_string(),
})?;
let subagent_session_id = subagent.id();
event_stream.subagent_spawned(subagent_session_id.clone());
let meta = acp::Meta::from_iter([(
SUBAGENT_SESSION_ID_META_KEY.into(),
subagent_session_id.to_string().into(),
)]);
event_stream.update_fields_with_meta(acp::ToolCallUpdateFields::new(), Some(meta));
Ok((subagent, subagent_session_id))
})?;
match subagent.wait_for_output(cx).await {
Ok(output) => {
event_stream.update_fields(
acp::ToolCallUpdateFields::new().content(vec![output.clone().into()]),
);
Ok(SpawnAgentToolOutput::Success {
session_id: subagent_session_id,
output,
})
}
Err(e) => {
let error = e.to_string();
event_stream.update_fields(
acp::ToolCallUpdateFields::new().content(vec![error.clone().into()]),
);
Err(SpawnAgentToolOutput::Error {
session_id: Some(subagent_session_id),
error,
})
}
}
})
}
fn replay(
&self,
_input: Self::Input,
output: Self::Output,
event_stream: ToolCallEventStream,
_cx: &mut App,
) -> Result<()> {
let session_id = match &output {
SpawnAgentToolOutput::Success { session_id, .. } => Some(session_id),
SpawnAgentToolOutput::Error { session_id, .. } => session_id.as_ref(),
};
if let Some(session_id) = session_id {
event_stream.subagent_spawned(session_id.clone());
let meta = acp::Meta::from_iter([(
SUBAGENT_SESSION_ID_META_KEY.into(),
session_id.to_string().into(),
)]);
event_stream.update_fields_with_meta(acp::ToolCallUpdateFields::new(), Some(meta));
}
let content = match &output {
SpawnAgentToolOutput::Success { output, .. } => output.into(),
SpawnAgentToolOutput::Error { error, .. } => error.into(),
};
event_stream.update_fields(acp::ToolCallUpdateFields::new().content(vec![content]));
Ok(())
}
}