diff --git a/src/TemplateArchiveProcessor.ts b/src/TemplateArchiveProcessor.ts
index 5708205..0fc0cc2 100644
--- a/src/TemplateArchiveProcessor.ts
+++ b/src/TemplateArchiveProcessor.ts
@@ -38,6 +38,34 @@ export type InitResponse = {
     state: State;
 }
 
+function isObject(value: unknown): value is Record<string, unknown> {
+    return typeof value === 'object' && value !== null;
+}
+
+function validateTriggerResponse(result: unknown): asserts result is TriggerResponse {
+    if (!isObject(result)) {
+        throw new Error('Invalid trigger result: expected an object');
+    }
+    if (!isObject(result.result)) {
+        throw new Error('Invalid trigger result: missing result object');
+    }
+    if (!isObject(result.state)) {
+        throw new Error('Invalid trigger result: missing state object');
+    }
+    if (!Array.isArray(result.events)) {
+        throw new Error('Invalid trigger result: events must be an array');
+    }
+}
+
+function validateInitResponse(result: unknown): asserts result is InitResponse {
+    if (!isObject(result)) {
+        throw new Error('Invalid init result: expected an object');
+    }
+    if (!isObject(result.state)) {
+        throw new Error('Invalid init result: missing state object');
+    }
+}
+
 /**
  * A template archive processor: can draft content using the
  * templatemark for the archive and trigger the logic of the archive
@@ -124,7 +152,9 @@ export class TemplateArchiveProcessor {
                 arguments: [data, request, state, resolvedTime, resolvedOffset]
             });
             if(evalResponse.result) {
-                return evalResponse.result;
+                const executionResult = await evalResponse.result;
+                validateTriggerResponse(executionResult);
+                return executionResult;
             }
             else {
                 throw new Error('Trigger failed with message: ' + evalResponse.message);
@@ -175,7 +205,9 @@ export class TemplateArchiveProcessor {
                 arguments: [data, resolvedTime, resolvedOffset]
             });
             if(evalResponse.result) {
-                return evalResponse.result;
+                const executionResult = await evalResponse.result;
+                validateInitResponse(executionResult);
+                return executionResult;
             }
             else {
                 throw new Error('Init failed with message: ' + evalResponse.message);
diff --git a/test/TemplateArchiveProcessor.test.ts b/test/TemplateArchiveProcessor.test.ts
index c82026b..2991d26 100644
--- a/test/TemplateArchiveProcessor.test.ts
+++ b/test/TemplateArchiveProcessor.test.ts
@@ -1,56 +1,50 @@
 import {Template} from '@accordproject/cicero-core';
 import { TemplateArchiveProcessor } from '../src/TemplateArchiveProcessor';
+import { JavaScriptEvaluator } from '../src/JavaScriptEvaluator';
+
+const data = {
+    "$class": "io.clause.latedeliveryandpenalty@0.1.0.TemplateModel",
+    "forceMajeure": true,
+    "penaltyDuration": {
+        "$class": "org.accordproject.time@0.3.0.Duration",
+        "amount": 2,
+        "unit": "days"
+    },
+    "penaltyPercentage": 10.5,
+    "capPercentage": 55,
+    "termination": {
+        "$class": "org.accordproject.time@0.3.0.Duration",
+        "amount": 15,
+        "unit": "days"
+    },
+    "fractionalPart": "days",
+    "clauseId": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8",
+    "$identifier": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8"
+};
+
+const request = {
+    goodsValue: 100
+};
+
+async function createTemplateArchiveProcessor() {
+    const template = await Template.fromDirectory('test/archives/latedeliveryandpenalty-typescript', {offline: true});
+    return new TemplateArchiveProcessor(template);
+}
 
 describe('template archive processor', () => {
+    afterEach(() => {
+        jest.restoreAllMocks();
+    });
+
     test('should draft a template', async () => {
-        const template = await Template.fromDirectory('test/archives/latedeliveryandpenalty-typescript', {offline: true});
-        const templateArchiveProcessor = new TemplateArchiveProcessor(template);
-        const data = {
-            "$class": "io.clause.latedeliveryandpenalty@0.1.0.TemplateModel",
-            "forceMajeure": true,
-            "penaltyDuration": {
-                "$class": "org.accordproject.time@0.3.0.Duration",
-                "amount": 2,
-                "unit": "days"
-            },
-            "penaltyPercentage": 10.5,
-            "capPercentage": 55,
-            "termination": {
-                "$class": "org.accordproject.time@0.3.0.Duration",
-                "amount": 15,
-                "unit": "days"
-            },
-            "fractionalPart": "days",
-            "clauseId": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8",
-            "$identifier": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8"
-        };
+        const templateArchiveProcessor = await createTemplateArchiveProcessor();
         const options = {};
         const result = await templateArchiveProcessor.draft(data, 'markdown', options);
         expect(result).toMatchSnapshot();
     });
 
     test('should init a template', async () => {
-        const template = await Template.fromDirectory('test/archives/latedeliveryandpenalty-typescript', {offline: true});
-        const templateArchiveProcessor = new TemplateArchiveProcessor(template);
-        const data = {
-            "$class": "io.clause.latedeliveryandpenalty@0.1.0.TemplateModel",
-            "forceMajeure": true,
-            "penaltyDuration": {
-                "$class": "org.accordproject.time@0.3.0.Duration",
-                "amount": 2,
-                "unit": "days"
-            },
-            "penaltyPercentage": 10.5,
-            "capPercentage": 55,
-            "termination": {
-                "$class": "org.accordproject.time@0.3.0.Duration",
-                "amount": 15,
-                "unit": "days"
-            },
-            "fractionalPart": "days",
-            "clauseId": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8",
-            "$identifier": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8"
-        };
+        const templateArchiveProcessor = await createTemplateArchiveProcessor();
         const response = await templateArchiveProcessor.init(data);
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         const payload:any = response.state;
@@ -58,30 +52,7 @@ describe('template archive processor', () => {
     });
 
     test('should trigger a template', async () => {
-        const template = await Template.fromDirectory('test/archives/latedeliveryandpenalty-typescript', {offline: true});
-        const templateArchiveProcessor = new TemplateArchiveProcessor(template);
-        const data = {
-            "$class": "io.clause.latedeliveryandpenalty@0.1.0.TemplateModel",
-            "forceMajeure": true,
-            "penaltyDuration": {
-                "$class": "org.accordproject.time@0.3.0.Duration",
-                "amount": 2,
-                "unit": "days"
-            },
-            "penaltyPercentage": 10.5,
-            "capPercentage": 55,
-            "termination": {
-                "$class": "org.accordproject.time@0.3.0.Duration",
-                "amount": 15,
-                "unit": "days"
-            },
-            "fractionalPart": "days",
-            "clauseId": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8",
-            "$identifier": "c88e5ed7-c3e0-4249-a99c-ce9278684ac8"
-        };
-        const request = {
-            goodsValue: 100
-        };
+        const templateArchiveProcessor = await createTemplateArchiveProcessor();
 
         // first we init the template
         const stateResponse = await templateArchiveProcessor.init(data);
@@ -100,4 +71,27 @@ describe('template archive processor', () => {
         // the events should have been emitted
         expect(payload.events[0].penaltyCalculated).toBe(true);
     });
+
+    test.each([
+        [{ state: {}, events: [] }, 'Invalid trigger result: missing result object'],
+        [{ result: {}, events: [] }, 'Invalid trigger result: missing state object'],
+        [{ result: {}, state: {}, events: {} }, 'Invalid trigger result: events must be an array']
+    ])('should validate malformed trigger result %j', async (triggerResult, errorMessage) => {
+        const templateArchiveProcessor = await createTemplateArchiveProcessor();
+        const stateResponse = await templateArchiveProcessor.init(data);
+        jest.spyOn(JavaScriptEvaluator.prototype, 'evalDangerously').mockResolvedValueOnce({
+            result: Promise.resolve(triggerResult)
+        });
+
+        await expect(templateArchiveProcessor.trigger(data, request, stateResponse.state)).rejects.toThrow(errorMessage);
+    });
+
+    test('should validate malformed init result', async () => {
+        const templateArchiveProcessor = await createTemplateArchiveProcessor();
+        jest.spyOn(JavaScriptEvaluator.prototype, 'evalDangerously').mockResolvedValueOnce({
+            result: Promise.resolve({})
+        });
+
+        await expect(templateArchiveProcessor.init(data)).rejects.toThrow('Invalid init result: missing state object');
+    });
 });