huskies: merge 540_bug_get_agent_output_mcp_tool_returns_no_agent_for_exited_agents_instead_of_reading_session_logs_from_disk

server/src/http/mcp/mod.rs

@@ -219,10 +219,42 @@ fn handle_agent_output_sse(
 
     let mut rx = match ctx.agents.subscribe(&story_id, &agent_name) {
         Ok(rx) => rx,
-        Err(e) => return to_sse_response(JsonRpcResponse::success(
-            id,
-            json!({ "content": [{"type": "text", "text": e}], "isError": true }),
-        )),
+        Err(_) => {
+            // Agent not in pool (exited or never started) — fall back to disk logs.
+            let text = if let Ok(project_root) = ctx.agents.get_project_root(&ctx.state) {
+                use crate::agent_log;
+                let log_files = agent_log::list_story_log_files(
+                    &project_root,
+                    &story_id,
+                    Some(&agent_name),
+                );
+                if log_files.is_empty() {
+                    format!("No log files found for story '{story_id}' agent '{agent_name}'.")
+                } else {
+                    let mut all_lines: Vec<String> = Vec::new();
+                    for path in &log_files {
+                        let file_name =
+                            path.file_name().and_then(|n| n.to_str()).unwrap_or("?");
+                        all_lines.push(format!(
+                            "=== {} ===",
+                            file_name.trim_end_matches(".log")
+                        ));
+                        match agent_log::read_log_as_readable_lines(path) {
+                            Ok(lines) => all_lines.extend(lines),
+                            Err(e) => all_lines.push(format!("[ERROR reading log: {e}]")),
+                        }
+                        all_lines.push(String::new());
+                    }
+                    all_lines.join("\n")
+                }
+            } else {
+                format!("No log files found for story '{story_id}' agent '{agent_name}'.")
+            };
+            return to_sse_response(JsonRpcResponse::success(
+                id,
+                json!({ "content": [{"type": "text", "text": text}] }),
+            ));
+        }
     };
 
     let final_id = id;
@@ -1799,7 +1831,8 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn mcp_post_sse_get_agent_output_no_agent_returns_sse_error() {
+    async fn mcp_post_sse_get_agent_output_no_agent_no_logs_returns_not_found() {
+        // Agent not in pool and no log files → SSE success with "No log files found" message.
         let tmp = tempfile::tempdir().unwrap();
         let ctx = std::sync::Arc::new(test_ctx(tmp.path()));
         let cli = poem::test::TestClient::new(test_mcp_app(ctx));
@@ -1816,5 +1849,40 @@ mod tests {
         );
         let body = resp.0.into_body().into_string().await.unwrap();
         assert!(body.contains("data:"), "expected SSE data prefix: {body}");
+        // Must NOT return isError — should be a success result with "No log files found"
+        assert!(!body.contains("isError"), "expected no isError for missing agent: {body}");
+        assert!(body.contains("No log files found"), "expected not-found message: {body}");
+    }
+
+    #[tokio::test]
+    async fn mcp_post_sse_get_agent_output_exited_agent_reads_disk_logs() {
+        use crate::agent_log::AgentLogWriter;
+        use crate::agents::AgentEvent;
+        // Agent has exited (not in pool) but wrote logs to disk.
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let mut writer =
+            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-sse").unwrap();
+        writer
+            .write_event(&AgentEvent::Output {
+                story_id: "42_story_foo".to_string(),
+                agent_name: "coder-1".to_string(),
+                text: "disk output".to_string(),
+            })
+            .unwrap();
+        drop(writer);
+
+        let ctx = std::sync::Arc::new(test_ctx(root));
+        let cli = poem::test::TestClient::new(test_mcp_app(ctx));
+        let resp = cli
+            .post("/mcp")
+            .header("content-type", "application/json")
+            .header("accept", "text/event-stream")
+            .body(r#"{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"get_agent_output","arguments":{"story_id":"42_story_foo","agent_name":"coder-1"}}}"#)
+            .send()
+            .await;
+        let body = resp.0.into_body().into_string().await.unwrap();
+        assert!(body.contains("disk output"), "expected disk log content in SSE response: {body}");
+        assert!(!body.contains("isError"), "expected no error for exited agent with logs: {body}");
     }
 }