diff --git a/internal/p9/server.go b/internal/p9/server.go
index 323c6fc..4f967df 100644
--- a/internal/p9/server.go
+++ b/internal/p9/server.go
@@ -47,6 +47,7 @@ import (
 	"ollie/pkg/agent"
 	"ollie/pkg/backend"
 	"ollie/pkg/config"
+	olog "ollie/pkg/log"
 	"ollie/pkg/tools"
 	"ollie/pkg/tools/execute"
 )
@@ -220,7 +221,7 @@ func (s *Server) Serve(conn net.Conn) {
 		fc, err := plan9.ReadFcall(conn)
 		if err != nil {
 			if err != io.EOF {
-				fmt.Fprintf(os.Stderr, "olliesrv: read: %v\n", err)
+				plog.Error("read: %v", err)
 			}
 			return
 		}
@@ -228,13 +229,7 @@ func (s *Server) Serve(conn net.Conn) {
 	}
 }
 
-var debug = os.Getenv("OLLIE_9P_DEBUG") != ""
-
-func dbg(format string, args ...any) {
-	if debug {
-		fmt.Fprintf(os.Stderr, "9p: "+format+"\n", args...)
-	}
-}
+var plog = olog.New("9p")
 
 func (s *Server) handle(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	switch fc.Type {
@@ -243,12 +238,12 @@ func (s *Server) handle(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 		if msize > 65536 {
 			msize = 65536
 		}
-		dbg("Tversion msize=%d", msize)
+		plog.Debug("Tversion msize=%d", msize)
 		return &plan9.Fcall{Type: plan9.Rversion, Tag: fc.Tag, Msize: msize, Version: "9P2000"}
 	case plan9.Tauth:
 		return errFcall(fc, "no auth required")
 	case plan9.Tattach:
-		dbg("Tattach fid=%d", fc.Fid)
+		plog.Debug("Tattach fid=%d", fc.Fid)
 		return s.attach(cs, fc)
 	case plan9.Twalk:
 		return s.walk(cs, fc)
@@ -408,7 +403,7 @@ func (s *Server) walk(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 		return &plan9.Fcall{Type: plan9.Rwalk, Tag: fc.Tag, Wqid: []plan9.Qid{}}
 	}
 
-	dbg("Twalk fid=%d newfid=%d from=%q wnames=%v", fc.Fid, fc.Newfid, f.path, fc.Wname)
+	plog.Debug("Twalk fid=%d newfid=%d from=%q wnames=%v", fc.Fid, fc.Newfid, f.path, fc.Wname)
 
 	wqids := make([]plan9.Qid, 0, len(fc.Wname))
 	cur := f.path
@@ -456,7 +451,7 @@ func (s *Server) open(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	}
 
 	f.mode = fc.Mode
-	dbg("Topen fid=%d path=%q mode=%d", fc.Fid, f.path, fc.Mode)
+	plog.Debug("Topen fid=%d path=%q mode=%d", fc.Fid, f.path, fc.Mode)
 	return &plan9.Fcall{Type: plan9.Ropen, Tag: fc.Tag, Qid: f.qid}
 }
 
@@ -473,7 +468,7 @@ func (s *Server) create(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	}
 
 	newPath := pathJoin(f.path, fc.Name)
-	dbg("Tcreate parent=%q name=%q", f.path, fc.Name)
+	plog.Debug("Tcreate parent=%q name=%q", f.path, fc.Name)
 	// (e.g. touch) produces a real file.
 	switch f.path {
 	case "/a":
@@ -517,34 +512,34 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	cs.mu.RUnlock()
 
 	if isDir {
-		dbg("Tread dir path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread dir path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		data := s.readDir(path, fc.Offset, fc.Count)
-		dbg("Rread dir path=%q len=%d", path, len(data))
+		plog.Debug("Rread dir path=%q len=%d", path, len(data))
 		return &plan9.Fcall{Type: plan9.Rread, Tag: fc.Tag, Count: uint32(len(data)), Data: data}
 	}
 
 	// s/new and s/idx are served from the session store.
 	if path == "/s/new" || path == "/s/idx" {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := s.sessionStore.Get(pathBase(path))
 		if err != nil {
-			dbg("Rread path=%q err=%v", path, err)
+			plog.Debug("Rread path=%q err=%v", path, err)
 			return errFcall(fc, err.Error())
 		}
-		dbg("Rread path=%q content_len=%d", path, len(content))
+		plog.Debug("Rread path=%q content_len=%d", path, len(content))
 		return s.readSlice(fc, content)
 	}
 
 	// backends is a static list of ollie-provided backends.
 	if path == "/backends" {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content := []byte(strings.Join(backend.Backends(), "\n") + "\n")
 		return s.readSlice(fc, content)
 	}
 
 	// help is served from ~/.config/ollie/help.md.
 	if path == "/help" {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := os.ReadFile(s.helpPath())
 		if err != nil {
 			return errFcall(fc, err.Error())
@@ -554,7 +549,7 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 
 	// Agent config files are served from the agent store.
 	if strings.HasPrefix(path, "/a/") {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := s.agentStore.Get(pathBase(path))
 		if err != nil {
 			return errFcall(fc, err.Error())
@@ -564,7 +559,7 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 
 	// Prompt files are served from the prompt store.
 	if strings.HasPrefix(path, "/p/") {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := s.promptStore.Get(pathBase(path))
 		if err != nil {
 			return errFcall(fc, err.Error())
@@ -574,7 +569,7 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 
 	// Memory files are served from the memory store.
 	if strings.HasPrefix(path, "/m/") {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := s.memStore.Get(pathBase(path))
 		if err != nil {
 			return errFcall(fc, err.Error())
@@ -584,7 +579,7 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 
 	// Plan files are served from the plan store.
 	if strings.HasPrefix(path, "/pl/") {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := s.planStore.Get(pathBase(path))
 		if err != nil {
 			return errFcall(fc, err.Error())
@@ -594,7 +589,7 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 
 	// Skill files are served from the skill store.
 	if strings.HasPrefix(path, "/sk/") {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := s.skillStore.Get(pathBase(path))
 		if err != nil {
 			return errFcall(fc, err.Error())
@@ -604,7 +599,7 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 
 	// Tool files are served from the tool store.
 	if strings.HasPrefix(path, "/t/") {
-		dbg("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+		plog.Debug("Tread path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 		content, err := s.toolStore.Get(pathBase(path))
 		if err != nil {
 			return errFcall(fc, err.Error())
@@ -616,10 +611,10 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	if strings.HasPrefix(path, "/s/") {
 		parts := strings.SplitN(strings.TrimPrefix(path, "/"), "/", 3)
 		if len(parts) == 3 {
-			dbg("Tread session file path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
+			plog.Debug("Tread session file path=%q offset=%d count=%d", path, fc.Offset, fc.Count)
 			store, ok := s.sessionFileStore(parts[1])
 			if !ok {
-				dbg("Rread session not found: %s", parts[1])
+				plog.Debug("Rread session not found: %s", parts[1])
 				return &plan9.Fcall{Type: plan9.Rread, Tag: fc.Tag, Count: 0}
 			}
 			// dequeue: non-zero offset is the trailing EOF read after a successful pop.
@@ -628,14 +623,14 @@ func (s *Server) read(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 			}
 			content, err := store.Get(parts[2])
 			if err != nil {
-				dbg("Rread session file err=%v", err)
+				plog.Debug("Rread session file err=%v", err)
 				return errFcall(fc, err.Error())
 			}
-			dbg("Rread session file path=%q content_len=%d", path, len(content))
+			plog.Debug("Rread session file path=%q content_len=%d", path, len(content))
 			return s.readSlice(fc, content)
 		}
 	}
-	dbg("Tread unhandled path=%q", path)
+	plog.Debug("Tread unhandled path=%q", path)
 	return &plan9.Fcall{Type: plan9.Rread, Tag: fc.Tag, Count: 0}
 }
 
@@ -667,7 +662,7 @@ func (s *Server) write(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 		cs.mu.Unlock()
 		return errFcall(fc, "bad fid")
 	}
-	dbg("Twrite fid=%d path=%q offset=%d len=%d", fc.Fid, f.path, fc.Offset, len(fc.Data))
+	plog.Debug("Twrite fid=%d path=%q offset=%d len=%d", fc.Fid, f.path, fc.Offset, len(fc.Data))
 	// Accumulate; the 9P client may split large writes across multiple Twrite messages.
 	end := int(fc.Offset) + len(fc.Data)
 	if end > len(f.writeBuf) {
@@ -688,7 +683,7 @@ func (s *Server) stat(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 		return errFcall(fc, "bad fid")
 	}
 	dir := s.makeStat(f.path)
-	dbg("Tstat path=%q mode=%o len=%d", f.path, dir.Mode, dir.Length)
+	plog.Debug("Tstat path=%q mode=%o len=%d", f.path, dir.Mode, dir.Length)
 	stat, err := dir.Bytes()
 	if err != nil {
 		return errFcall(fc, err.Error())
@@ -712,7 +707,7 @@ func (s *Server) wstat(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	}
 
 	oldName := pathBase(f.path)
-	dbg("Twstat path=%q oldName=%q newName=%q", f.path, oldName, newDir.Name)
+	plog.Debug("Twstat path=%q oldName=%q newName=%q", f.path, oldName, newDir.Name)
 	if newDir.Name == "" || newDir.Name == oldName {
 		return &plan9.Fcall{Type: plan9.Rwstat, Tag: fc.Tag}
 	}
@@ -828,7 +823,7 @@ func (s *Server) renameSession(oldID, newID string) error {
 	}
 
 	sess.appendChat([]byte(fmt.Sprintf("(session renamed: %s -> %s)\n", oldID, newID)))
-	fmt.Fprintf(os.Stderr, "olliesrv: renamed session %s -> %s\n", oldID, newID)
+	plog.Info("renamed session %s -> %s", oldID, newID)
 	return nil
 }
 
@@ -847,16 +842,16 @@ func (s *Server) clunk(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	}
 	cs.mu.Unlock()
 	if len(data) > 0 {
-		dbg("Tclunk flush path=%q writeBuf=%d", path, len(data))
+		plog.Debug("Tclunk flush path=%q writeBuf=%d", path, len(data))
 		input := strings.TrimSpace(string(data))
 		if s.isAsyncWrite(path) {
 			go s.handleWrite(path, input) //nolint:errcheck
 		} else if err := s.handleWrite(path, input); err != nil {
-			dbg("Tclunk handleWrite err=%v", err)
+			plog.Debug("Tclunk handleWrite err=%v", err)
 			return errFcall(fc, err.Error())
 		}
 	} else {
-		dbg("Tclunk fid=%d path=%q (no write)", fc.Fid, path)
+		plog.Debug("Tclunk fid=%d path=%q (no write)", fc.Fid, path)
 	}
 	return &plan9.Fcall{Type: plan9.Rclunk, Tag: fc.Tag}
 }
@@ -886,7 +881,7 @@ func (s *Server) remove(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 	}
 
 	path := f.path
-	dbg("Tremove path=%q", path)
+	plog.Debug("Tremove path=%q", path)
 	var err error
 	switch {
 	case strings.HasPrefix(path, "/a/"):
@@ -922,7 +917,7 @@ func (s *Server) remove(cs *connState, fc *plan9.Fcall) *plan9.Fcall {
 // Called synchronously from clunk; prompt writes are the exception (spawned
 // as a goroutine because they block for the entire agent turn).
 func (s *Server) handleWrite(path, input string) error {
-	dbg("handleWrite path=%q input_len=%d", path, len(input))
+	plog.Debug("handleWrite path=%q input_len=%d", path, len(input))
 	if input == "" {
 		return nil
 	}
@@ -973,7 +968,7 @@ func (s *Server) handleWrite(path, input string) error {
 
 // handleNewSession parses KV pairs (one per line or space-separated) and creates a session.
 func (s *Server) handleNewSession(input string) error {
-	dbg("handleNewSession input=%q", input)
+	plog.Debug("handleNewSession input=%q", input)
 	// Accept both newline-separated and space-separated KV pairs.
 	args := strings.Fields(input)
 	return s.createSession(args)
@@ -1100,7 +1095,7 @@ func (s *Server) createSession(args []string) error {
 	s.sessions[sessID] = sess
 	s.mu.Unlock()
 
-	fmt.Fprintf(os.Stderr, "olliesrv: new session %s (backend=%s model=%s agent=%s)\n",
+	plog.Info("new session %s (backend=%s model=%s agent=%s)",
 		sessID, core.BackendName(), core.ModelName(), core.AgentName())
 	return nil
 }
@@ -1126,7 +1121,7 @@ func (s *Server) killSession(id string) {
 	if sess != nil {
 		sess.cancel()
 		sess.core.Close()
-		fmt.Fprintf(os.Stderr, "olliesrv: killed session %s\n", id)
+		plog.Info("killed session %s", id)
 	}
 }
 
diff --git a/internal/p9/sessionfilestore.go b/internal/p9/sessionfilestore.go
index 6d3180b..f20271b 100644
--- a/internal/p9/sessionfilestore.go
+++ b/internal/p9/sessionfilestore.go
@@ -216,7 +216,7 @@ func (s *SessionFileStore) handleCtl(input string) error {
 	case "rn":
 		if name := strings.TrimSpace(input[3:]); name != "" {
 			if err := s.rename(name); err != nil {
-				fmt.Fprintf(os.Stderr, "olliesrv: rename: %v\n", err)
+				plog.Error("rename: %v", err)
 			}
 		}
 	case "compact", "clear", "backend", "model", "models",