fix: add GitHub Copilot optimization headers for billing.

crates/forge_app/src/agent_executor.rs

@@ -53,7 +53,11 @@ impl<S: Services> AgentExecutor<S> {
         .await?;
 
         // Create a new conversation for agent execution
-        let conversation = Conversation::generate().title(task.clone());
+        // Create context with agent initiator since it's spawned by a parent agent
+        let context = forge_domain::Context::default().initiator("agent".to_string());
+        let conversation = Conversation::generate()
+            .title(task.clone())
+            .context(context.clone());
         self.services
             .conversation_service()
             .upsert_conversation(conversation.clone())

crates/forge_app/src/dto/anthropic/transforms/auth_system_message.rs

@@ -90,6 +90,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         Request::try_from(context).unwrap()

crates/forge_app/src/dto/anthropic/transforms/set_cache.rs

@@ -101,6 +101,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         let request = Request::try_from(context).expect("Failed to convert context to request");
@@ -239,6 +240,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         let request = Request::try_from(context).expect("Failed to convert context to request");

crates/forge_app/src/dto/openai/request.rs

@@ -266,6 +266,10 @@ pub struct Request {
     pub parallel_tool_calls: Option<bool>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub session_id: Option<String>,
+    /// Indicates who initiated the conversation: "user" or "agent".
+    /// Used for GitHub Copilot billing optimization. Not serialized to API.
+    #[serde(skip_serializing)]
+    pub initiator: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub stream_options: Option<StreamOptions>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -400,6 +404,7 @@ impl From<Context> for Request {
                                               * on model capabilities */
             stream_options: Some(StreamOptions { include_usage: Some(true) }),
             session_id: context.conversation_id.map(|id| id.to_string()),
+            initiator: context.initiator,
             reasoning: context.reasoning,
             reasoning_effort: Default::default(),
             max_completion_tokens: Default::default(),

crates/forge_app/src/dto/openai/transformers/drop_tool_call.rs

@@ -71,6 +71,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         let request = Request::from(context);

crates/forge_app/src/dto/openai/transformers/set_cache.rs

@@ -87,6 +87,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         let request = Request::from(context);

crates/forge_domain/src/context.rs

@@ -402,6 +402,10 @@ impl std::ops::DerefMut for MessageEntry {
 pub struct Context {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub conversation_id: Option<ConversationId>,
+    /// Indicates who initiated the conversation: "user" or "agent".
+    /// Used for GitHub Copilot billing optimization.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub initiator: Option<String>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub messages: Vec<MessageEntry>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]

crates/forge_repo/src/conversation/conversation_record.rs

@@ -724,6 +724,8 @@ impl From<ReasoningConfigRecord> for forge_domain::ReasoningConfig {
 pub(super) struct ContextRecord {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     conversation_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    initiator: Option<String>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     messages: Vec<ContextMessageRecord>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
@@ -748,6 +750,7 @@ impl From<&Context> for ContextRecord {
     fn from(context: &Context) -> Self {
         Self {
             conversation_id: context.conversation_id.as_ref().map(|id| id.into_string()),
+            initiator: context.initiator.clone(),
             messages: context
                 .messages
                 .iter()
@@ -803,6 +806,7 @@ impl TryFrom<ContextRecord> for Context {
 
         Ok(Context {
             conversation_id,
+            initiator: record.initiator,
             messages: messages?,
             tools: tools?,
             tool_choice: record.tool_choice.map(Into::into),

crates/forge_repo/src/provider/bedrock.rs

@@ -1669,6 +1669,7 @@ mod tests {
 
         let fixture = Context {
             conversation_id: None,
+            initiator: None,
             messages: vec![
                 ContextMessage::system("You are a helpful assistant").into(),
                 ContextMessage::Text(TextMessage::new(Role::User, "Hello!")).into(),
@@ -1701,6 +1702,7 @@ mod tests {
 
         let fixture = Context {
             conversation_id: None,
+            initiator: None,
             messages: vec![],
             tools: vec![],
             tool_choice: None,
@@ -1726,6 +1728,7 @@ mod tests {
 
         let fixture = Context {
             conversation_id: None,
+            initiator: None,
             messages: vec![],
             tools: vec![],
             tool_choice: None,
@@ -1759,6 +1762,7 @@ mod tests {
 
         let fixture = Context {
             conversation_id: None,
+            initiator: None,
             messages: vec![],
             tools: vec![],
             tool_choice: None,

crates/forge_repo/src/provider/bedrock_cache.rs

@@ -103,6 +103,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         let request = ConverseStreamInput::from_domain(context).expect("Failed to convert context");
@@ -130,6 +131,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         let request = ConverseStreamInput::from_domain(context).expect("Failed to convert context");
@@ -159,6 +161,7 @@ mod tests {
             reasoning: None,
             stream: None,
             response_format: None,
+            initiator: None,
         };
 
         let request = ConverseStreamInput::from_domain(context).expect("Failed to convert context");