diff --git a/pkg/engine/control.go b/pkg/engine/control.go
new file mode 100644
index 00000000..7bb45c0a
--- /dev/null
+++ b/pkg/engine/control.go
@@ -0,0 +1,20 @@
+package engine
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/gptscript-ai/gptscript/pkg/types"
+)
+
+func (e *Engine) runBreak(tool types.Tool, input string) (cmdOut *Return, cmdErr error) {
+	info, err := json.Marshal(tool)
+	if err != nil {
+		return nil, err
+	}
+	var dict map[string]interface{}
+	json.Unmarshal(info, &dict)
+	dict["input"] = input
+	info, err = json.Marshal(dict)
+	return nil, fmt.Errorf("TOOL_BREAK: %s", info)
+}
diff --git a/pkg/engine/engine.go b/pkg/engine/engine.go
index f901bf63..73a5f7dd 100644
--- a/pkg/engine/engine.go
+++ b/pkg/engine/engine.go
@@ -252,6 +252,8 @@ func (e *Engine) Start(ctx Context, input string) (ret *Return, _ error) {
 			return e.runOpenAPI(tool, input)
 		} else if tool.IsEcho() {
 			return e.runEcho(tool)
+		} else if tool.IsBreak() {
+			return e.runBreak(tool, input)
 		}
 		s, err := e.runCommand(ctx, tool, input, ctx.ToolCategory)
 		if err != nil {
diff --git a/pkg/types/tool.go b/pkg/types/tool.go
index 2c218e2c..7a5c842d 100644
--- a/pkg/types/tool.go
+++ b/pkg/types/tool.go
@@ -19,6 +19,7 @@ const (
 	DaemonPrefix  = "#!sys.daemon"
 	OpenAPIPrefix = "#!sys.openapi"
 	EchoPrefix    = "#!sys.echo"
+	BreakPrefix   = "#!sys.break"
 	CommandPrefix = "#!"
 )
 
@@ -664,6 +665,10 @@ func (t Tool) IsEcho() bool {
 	return strings.HasPrefix(t.Instructions, EchoPrefix)
 }
 
+func (t Tool) IsBreak() bool {
+	return strings.HasPrefix(t.Instructions, BreakPrefix)
+}
+
 func (t Tool) IsHTTP() bool {
 	return strings.HasPrefix(t.Instructions, "#!http://") ||
 		strings.HasPrefix(t.Instructions, "#!https://")