diff --git a/pr-review/package-lock.json b/pr-review/package-lock.json
index f31ae83..9271c98 100644
--- a/pr-review/package-lock.json
+++ b/pr-review/package-lock.json
@@ -19,8 +19,7 @@
         "mollitia": "0.2.0",
         "octokit": "5.0.3",
         "parse-diff": "0.11.1",
-        "zod": "3.25.76",
-        "zod-to-json-schema": "3.24.6"
+        "zod": "4.0.5"
       },
       "devDependencies": {
         "@eslint/js": "9.31.0",
@@ -1725,6 +1724,15 @@
         "zod": "^3.25.76"
       }
     },
+    "node_modules/@sap-ai-sdk/prompt-registry/node_modules/zod": {
+      "version": "3.25.76",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
+      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
+    },
     "node_modules/@sap-cloud-sdk/connectivity": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/@sap-cloud-sdk/connectivity/-/connectivity-4.0.2.tgz",
@@ -7995,22 +8003,13 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.25.76",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
-      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "version": "4.0.5",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.0.5.tgz",
+      "integrity": "sha512-/5UuuRPStvHXu7RS+gmvRf4NXrNxpSllGwDnCBcJZtQsKrviYXm54yDGV2KYNLT5kq0lHGcl7lqWJLgSaG+tgA==",
       "license": "MIT",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
       }
-    },
-    "node_modules/zod-to-json-schema": {
-      "version": "3.24.6",
-      "resolved": "https://registry.npmjs.org/zod-to-json-schema/-/zod-to-json-schema-3.24.6.tgz",
-      "integrity": "sha512-h/z3PKvcTcTetyjl1fkj79MHNEjm+HpD6NXheWjzOekY7kV+lwDYnHw+ivHkijnCSMz1yJaWBD9vu/Fcmk+vEg==",
-      "license": "ISC",
-      "peerDependencies": {
-        "zod": "^3.24.1"
-      }
     }
   }
 }
diff --git a/pr-review/package.json b/pr-review/package.json
index 7a7e6a9..fdc1406 100644
--- a/pr-review/package.json
+++ b/pr-review/package.json
@@ -27,8 +27,7 @@
     "mollitia": "0.2.0",
     "octokit": "5.0.3",
     "parse-diff": "0.11.1",
-    "zod": "3.25.76",
-    "zod-to-json-schema": "3.24.6"
+    "zod": "4.0.5"
   },
   "devDependencies": {
     "@eslint/js": "9.31.0",
diff --git a/pr-review/src/ai-core-client.ts b/pr-review/src/ai-core-client.ts
index c67e903..233b7a6 100644
--- a/pr-review/src/ai-core-client.ts
+++ b/pr-review/src/ai-core-client.ts
@@ -3,7 +3,6 @@ import { ChatMessage, OrchestrationClient, TokenUsage } from "@sap-ai-sdk/orches
 import axios from "axios"
 import { inspect } from "node:util"
 import { z } from "zod"
-import { zodToJsonSchema } from "zod-to-json-schema"
 import { config } from "./config.js"
 
 let modelName = config.model
@@ -63,7 +62,7 @@ export async function chatCompletion(messages: ChatMessage[]): Promise<string> {
  */
 export async function chatCompletionWithJsonSchema<T extends z.ZodTypeAny>(zodSchema: T, messages: ChatMessage[]): Promise<z.infer<T>> {
   process.env.AICORE_SERVICE_KEY = JSON.stringify(config.aicoreServiceKey)
-  const jsonSchema = zodToJsonSchema(zodSchema)
+  const jsonSchema = z.toJSONSchema(zodSchema)
 
   let responseJson
   try {
@@ -102,11 +101,11 @@ export async function chatCompletionWithJsonSchema<T extends z.ZodTypeAny>(zodSc
   core.info(responseJson)
   responseJson = responseJson.slice(responseJson.indexOf("{"), responseJson.lastIndexOf("}") + 1)
   try {
-    return zodSchema.parse(JSON.parse(responseJson)) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    return zodSchema.parse(JSON.parse(responseJson))
   } catch (error) {
     if (error instanceof Error) core.warning(`Failed to parse JSON. Trying to replace newlines. Error was: ${error.message}`)
     const json = responseJson.replaceAll(/"(?:[^"\\]|\\.)*"/g, matched => matched.replaceAll("\n", String.raw`\n`))
-    return zodSchema.parse(JSON.parse(json)) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    return zodSchema.parse(JSON.parse(json))
   }
 }
 
diff --git a/pr-review/src/config.ts b/pr-review/src/config.ts
index a2c3399..7237af6 100644
--- a/pr-review/src/config.ts
+++ b/pr-review/src/config.ts
@@ -27,7 +27,7 @@ if (process.env.NODE_ENV === "development") {
 function parseInput<T extends z.ZodTypeAny>(zodSchema: T, name: string): z.infer<T> {
   const value: string = core.getInput(name)
   try {
-    return zodSchema.parse(value) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    return zodSchema.parse(value)
   } catch (error) {
     if (error instanceof Error) {
       core.error(`Failed to parse input "${name}": \`${value}\``)
@@ -40,7 +40,7 @@ function parseInput<T extends z.ZodTypeAny>(zodSchema: T, name: string): z.infer
 function parseInputAsJson<T extends z.ZodTypeAny>(zodSchema: T, name: string): z.infer<T> {
   const json: string = core.getInput(name)
   try {
-    return zodSchema.parse(JSON.parse(json)) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    return zodSchema.parse(JSON.parse(json))
   } catch (error) {
     if (error instanceof Error) {
       core.error(`Failed to parse input "${name}": \`${json}\``)
@@ -56,7 +56,7 @@ function parseInputAsArray<T extends z.ZodTypeAny>(zodSchema: T, name: string):
     .split(/[\n,]/)
     .map(v => v.trim())
     .filter(Boolean)
-    .map(v => zodSchema.parse(v) as z.infer<T>) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    .map(v => zodSchema.parse(v) as z.infer<T>)
 }
 
 function setSecret<T>(value: T): T {
diff --git a/pr-review/src/zod-schema.ts b/pr-review/src/zod-schema.ts
index a651f9d..0124d9d 100644
--- a/pr-review/src/zod-schema.ts
+++ b/pr-review/src/zod-schema.ts
@@ -32,9 +32,9 @@ export const ModelName: ZodType<ChatModel> = z.string()
 export type ModelName = z.infer<typeof ModelName>
 
 // DeploymentConfig
-export const DeploymentConfig: ZodType<ResourceGroupConfig> = z.record(z.any())
+export const DeploymentConfig: ZodType<ResourceGroupConfig> = z.record(z.any(), z.any())
 export type DeploymentConfig = z.infer<typeof DeploymentConfig>
 
 // ModelParameters
-export const ModelParameters: ZodType<LlmModelParams> = z.record(z.any())
+export const ModelParameters: ZodType<LlmModelParams> = z.record(z.any(), z.any())
 export type ModelParameters = z.infer<typeof ModelParameters>
diff --git a/pr-summary/package-lock.json b/pr-summary/package-lock.json
index 9ca2eb5..1edda57 100644
--- a/pr-summary/package-lock.json
+++ b/pr-summary/package-lock.json
@@ -18,7 +18,7 @@
         "mollitia": "0.2.0",
         "octokit": "5.0.3",
         "parse-diff": "0.11.1",
-        "zod": "3.25.76"
+        "zod": "4.0.5"
       },
       "devDependencies": {
         "@eslint/js": "9.31.0",
@@ -1416,6 +1416,15 @@
         "zod": "^3.25.76"
       }
     },
+    "node_modules/@sap-ai-sdk/prompt-registry/node_modules/zod": {
+      "version": "3.25.76",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
+      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
+    },
     "node_modules/@sap-cloud-sdk/connectivity": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/@sap-cloud-sdk/connectivity/-/connectivity-4.0.2.tgz",
@@ -7596,9 +7605,9 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.25.76",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
-      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "version": "4.0.5",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.0.5.tgz",
+      "integrity": "sha512-/5UuuRPStvHXu7RS+gmvRf4NXrNxpSllGwDnCBcJZtQsKrviYXm54yDGV2KYNLT5kq0lHGcl7lqWJLgSaG+tgA==",
       "license": "MIT",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
diff --git a/pr-summary/package.json b/pr-summary/package.json
index 0075e3c..4976185 100644
--- a/pr-summary/package.json
+++ b/pr-summary/package.json
@@ -26,7 +26,7 @@
     "mollitia": "0.2.0",
     "octokit": "5.0.3",
     "parse-diff": "0.11.1",
-    "zod": "3.25.76"
+    "zod": "4.0.5"
   },
   "devDependencies": {
     "@eslint/js": "9.31.0",
diff --git a/pr-summary/src/config.ts b/pr-summary/src/config.ts
index 225574a..fe595cb 100644
--- a/pr-summary/src/config.ts
+++ b/pr-summary/src/config.ts
@@ -27,7 +27,7 @@ if (process.env.NODE_ENV === "development") {
 function parseInput<T extends z.ZodTypeAny>(zodSchema: T, name: string): z.infer<T> {
   const value: string = core.getInput(name)
   try {
-    return zodSchema.parse(value) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    return zodSchema.parse(value)
   } catch (error) {
     if (error instanceof Error) {
       core.error(`Failed to parse input "${name}": \`${value}\``)
@@ -40,7 +40,7 @@ function parseInput<T extends z.ZodTypeAny>(zodSchema: T, name: string): z.infer
 function parseInputAsJson<T extends z.ZodTypeAny>(zodSchema: T, name: string): z.infer<T> {
   const json: string = core.getInput(name)
   try {
-    return zodSchema.parse(JSON.parse(json)) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    return zodSchema.parse(JSON.parse(json))
   } catch (error) {
     if (error instanceof Error) {
       core.error(`Failed to parse input "${name}": \`${json}\``)
@@ -56,7 +56,7 @@ function parseInputAsArray<T extends z.ZodTypeAny>(zodSchema: T, name: string):
     .split(/[\n,]/)
     .map(v => v.trim())
     .filter(Boolean)
-    .map(v => zodSchema.parse(v) as z.infer<T>) // eslint-disable-line @typescript-eslint/no-unsafe-return
+    .map(v => zodSchema.parse(v) as z.infer<T>)
 }
 
 function setSecret<T>(value: T): T {
diff --git a/pr-summary/src/zod-schema.ts b/pr-summary/src/zod-schema.ts
index a651f9d..0124d9d 100644
--- a/pr-summary/src/zod-schema.ts
+++ b/pr-summary/src/zod-schema.ts
@@ -32,9 +32,9 @@ export const ModelName: ZodType<ChatModel> = z.string()
 export type ModelName = z.infer<typeof ModelName>
 
 // DeploymentConfig
-export const DeploymentConfig: ZodType<ResourceGroupConfig> = z.record(z.any())
+export const DeploymentConfig: ZodType<ResourceGroupConfig> = z.record(z.any(), z.any())
 export type DeploymentConfig = z.infer<typeof DeploymentConfig>
 
 // ModelParameters
-export const ModelParameters: ZodType<LlmModelParams> = z.record(z.any())
+export const ModelParameters: ZodType<LlmModelParams> = z.record(z.any(), z.any())
 export type ModelParameters = z.infer<typeof ModelParameters>