diff --git a/internal/p9/server.go b/internal/p9/server.go
index 41b6410..9ed4830 100644
--- a/internal/p9/server.go
+++ b/internal/p9/server.go
@@ -793,8 +793,8 @@ func (s *Server) handleRootCtl(input string) {
 }
 
 // createSession parses key=value options and starts a new agent session.
-// Recognised keys: backend, model, agent, workdir. Unknown keys are rejected.
-// Example: new backend=ollama model=qwen3:8b agent=myagent workdir=/home/lkn/src/myproject
+// Recognised keys: backend, model, agent, workdir. workdir is required.
+// Example: new workdir=/home/lkn/src/myproject backend=ollama model=qwen3:8b agent=myagent
 func (s *Server) createSession(args []string) error {
 	backendOverride := ""
 	modelOverride := ""
@@ -820,6 +820,10 @@ func (s *Server) createSession(args []string) error {
 		}
 	}
 
+	if workdir == "" {
+		return fmt.Errorf("workdir is required (e.g. new workdir=/path/to/project)")
+	}
+
 	var (
 		be  backend.Backend
 		err error