diff --git a/src/agents/types.ts b/src/agents/types.ts
index d2913ed..374d278 100644
--- a/src/agents/types.ts
+++ b/src/agents/types.ts
@@ -4,6 +4,9 @@ export interface CreateAgentInput {
 
   /** Unique identifier (lowercase letters, numbers, hyphens, starts with a letter). */
   identifier: string;
+
+  /** Identifier of the parent agent. Child inherits parent's secretMode and credential assignments. */
+  parentIdentifier?: string;
 }
 
 export interface CreateAgentResponse {