feat: projects as backend sources with system prompt injection (#8739)

Signed-off-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/goose/src/agents/agent.rs

@@ -366,6 +366,24 @@ impl Agent {
         messages
     }
 
+    async fn load_project_instructions(&self, session: &Session) -> Option<String> {
+        let thread_id = session.thread_id.as_deref()?;
+        let thread_mgr =
+            crate::session::ThreadManager::new(self.config.session_manager.storage().clone());
+        let thread = thread_mgr.get_thread(thread_id).await.ok()?;
+        let project_id = thread.metadata.project_id.as_deref()?;
+        let entry = crate::sources::read_project(project_id).ok()?;
+        let mut parts = Vec::new();
+        parts.push(format!("# Project: {}", entry.name));
+        if !entry.description.is_empty() {
+            parts.push(entry.description.clone());
+        }
+        if !entry.content.is_empty() {
+            parts.push(entry.content.clone());
+        }
+        Some(parts.join("\n\n"))
+    }
+
     async fn prepare_reply_context(
         &self,
         session_id: &str,
@@ -1251,6 +1269,11 @@ impl Agent {
             goose_mode,
             initial_messages,
         } = context;
+
+        if let Some(project_addendum) = self.load_project_instructions(&session).await {
+            system_prompt = format!("{system_prompt}\n\n{project_addendum}");
+        }
+
         self.reset_retry_attempts().await;
 
         let provider = self.provider().await?;

crates/goose/src/agents/platform_extensions/summon.rs

@@ -125,9 +125,10 @@ fn parse_agent_content(content: &str, path: &Path) -> Option<SourceEntry> {
         name: metadata.name,
         description,
         content: body,
-        directory: path.to_string_lossy().into_owned(),
+        path: path.to_string_lossy().into_owned(),
         global: false,
         supporting_files: Vec::new(),
+        properties: std::collections::HashMap::new(),
     })
 }
 
@@ -171,9 +172,10 @@ fn scan_recipes_from_dir(
                     name,
                     description: recipe.description.clone(),
                     content: recipe.instructions.clone().unwrap_or_default(),
-                    directory: path.to_string_lossy().into_owned(),
+                    path: path.to_string_lossy().into_owned(),
                     global: false,
                     supporting_files: Vec::new(),
+                    properties: std::collections::HashMap::new(),
                 });
             }
             Err(e) => {
@@ -598,9 +600,10 @@ impl SummonClient {
                 name: sr.name.clone(),
                 description,
                 content: String::new(),
-                directory: sr.path.clone(),
+                path: sr.path.clone(),
                 global: false,
                 supporting_files: Vec::new(),
+                properties: std::collections::HashMap::new(),
             });
         }
     }
@@ -1160,7 +1163,7 @@ impl SummonClient {
             }
         }
 
-        let recipe_file = load_local_recipe_file(&source.directory)
+        let recipe_file = load_local_recipe_file(&source.path)
             .map_err(|e| format!("Failed to load recipe '{}': {}", source.name, e))?;
 
         let param_values: Vec<(String, String)> = params
@@ -1193,10 +1196,10 @@ impl SummonClient {
         source: &SourceEntry,
         params: &DelegateParams,
     ) -> Result<Recipe, String> {
-        let agent_content = if source.directory.is_empty() {
+        let agent_content = if source.path.is_empty() {
             return Err("Agent source has no path".to_string());
         } else {
-            std::fs::read_to_string(&source.directory)
+            std::fs::read_to_string(&source.path)
                 .map_err(|e| format!("Failed to read agent file: {}", e))?
         };