diff --git a/lib/types/types.d.ts b/lib/types/types.d.ts
index 22e5e16..cef72e0 100644
--- a/lib/types/types.d.ts
+++ b/lib/types/types.d.ts
@@ -187,6 +187,7 @@ export type Caption = {
     language: string;
     file_id: string;
 };
+export declare function isCaption(obj: unknown): obj is Caption;
 export type JobStopData = {
     job_id: string;
 };
@@ -196,6 +197,7 @@ export type CallJobMetadata = {
     tr_id?: string;
     rec_id?: string;
 };
+export declare function isCallJobMetadata(obj: unknown): obj is CallJobMetadata;
 export type CallRecordingPropsMap = {
     [key: string]: CallJobMetadata;
 };
diff --git a/lib/types/types.js b/lib/types/types.js
index 665b00a..daf50b3 100644
--- a/lib/types/types.js
+++ b/lib/types/types.js
@@ -5,3 +5,40 @@ export var TranscribeAPI;
     TranscribeAPI["WhisperCPP"] = "whisper.cpp";
     TranscribeAPI["AzureAI"] = "azure";
 })(TranscribeAPI || (TranscribeAPI = {}));
+export function isCaption(obj) {
+    if (typeof obj !== 'object' || obj === null) {
+        return false;
+    }
+    const caption = obj;
+    if (typeof caption.title !== 'string') {
+        return false;
+    }
+    if (typeof caption.language !== 'string') {
+        return false;
+    }
+    if (typeof caption.file_id !== 'string') {
+        return false;
+    }
+    return true;
+}
+export function isCallJobMetadata(obj) {
+    if (typeof obj !== 'object' || obj === null) {
+        return false;
+    }
+    const metadata = obj;
+    if (typeof metadata.file_id !== 'string') {
+        return false;
+    }
+    if (typeof metadata.post_id !== 'string') {
+        return false;
+    }
+    // eslint-disable-next-line no-undefined
+    if (metadata.tr_id !== undefined && typeof metadata.tr_id !== 'string') {
+        return false;
+    }
+    // eslint-disable-next-line no-undefined
+    if (metadata.rec_id !== undefined && typeof metadata.rec_id !== 'string') {
+        return false;
+    }
+    return true;
+}
diff --git a/src/types/types.ts b/src/types/types.ts
index 0150ee4..9900f48 100644
--- a/src/types/types.ts
+++ b/src/types/types.ts
@@ -259,6 +259,28 @@ export type Caption = {
     file_id: string;
 };
 
+export function isCaption(obj: unknown): obj is Caption {
+    if (typeof obj !== 'object' || obj === null) {
+        return false;
+    }
+
+    const caption = obj as Caption;
+
+    if (typeof caption.title !== 'string') {
+        return false;
+    }
+
+    if (typeof caption.language !== 'string') {
+        return false;
+    }
+
+    if (typeof caption.file_id !== 'string') {
+        return false;
+    }
+
+    return true;
+}
+
 export type JobStopData = {
     job_id: string;
 };
@@ -270,6 +292,34 @@ export type CallJobMetadata = {
     rec_id?: string;
 };
 
+export function isCallJobMetadata(obj: unknown): obj is CallJobMetadata {
+    if (typeof obj !== 'object' || obj === null) {
+        return false;
+    }
+
+    const metadata = obj as CallJobMetadata;
+
+    if (typeof metadata.file_id !== 'string') {
+        return false;
+    }
+
+    if (typeof metadata.post_id !== 'string') {
+        return false;
+    }
+
+    // eslint-disable-next-line no-undefined
+    if (metadata.tr_id !== undefined && typeof metadata.tr_id !== 'string') {
+        return false;
+    }
+
+    // eslint-disable-next-line no-undefined
+    if (metadata.rec_id !== undefined && typeof metadata.rec_id !== 'string') {
+        return false;
+    }
+
+    return true;
+}
+
 export type CallRecordingPropsMap = {
     [key: string]: CallJobMetadata;
 };