diff --git a/bin/chat.js b/bin/chat.js
index 65d5f0a..fe8049d 100644
--- a/bin/chat.js
+++ b/bin/chat.js
@@ -21,13 +21,13 @@ const colors = {
 }
 
 /**
- * @import { ResponsesInput, ResponseInputItem } from './types.d.ts'
- * @param {ResponsesInput} chatInput
- * @returns {Promise<ResponseInputItem[]>}
+ * @import { ChatInput, Message } from './types.d.ts'
+ * @param {ChatInput} chatInput
+ * @returns {Promise<Message[]>}
  */
 async function sendToServer(chatInput) {
   // Send the request to the server
-  const response = await fetch('https://hyperparam.app/api/functions/openai/responses', {
+  const response = await fetch('https://hyperparam.app/api/functions/chat', {
     method: 'POST',
     headers: { 'Content-Type': 'application/json' },
     body: JSON.stringify(chatInput),
@@ -38,7 +38,7 @@ async function sendToServer(chatInput) {
   }
 
   // Process the streaming response
-  /** @type {ResponseInputItem[]} */
+  /** @type {Message[]} */
   const incoming = []
   const reader = response.body?.getReader()
   if (!reader) throw new Error('No response body')
@@ -89,11 +89,13 @@ async function sendToServer(chatInput) {
             summary: chunk.item.summary,
           }
           incoming.push(reasoningItem)
-        } else if (!chunk.key) {
-          console.log('Unknown chunk', chunk)
+        } else if (chunk.key || chunk.type === 'response.completed') {
+          // ignore
+        } else {
+          console.log('\nUnknown chunk', chunk)
         }
       } catch (err) {
-        console.error('Error parsing chunk', err)
+        console.error('\nError parsing chunk', err)
       }
     }
   }
@@ -105,15 +107,15 @@ async function sendToServer(chatInput) {
  * Will mutate the messages array!
  *
  * @import { ResponseFunctionToolCall, ToolHandler } from './types.d.ts'
- * @param {ResponseInputItem[]} input
+ * @param {Message[][]} messages
  * @returns {Promise<void>}
  */
-async function sendMessages(input) {
-  /** @type {ResponsesInput} */
+async function sendMessages(messages) {
+  /** @type {ChatInput} */
   const chatInput = {
     model: 'gpt-5',
     instructions,
-    input,
+    messages,
     reasoning: {
       effort: 'low',
     },
@@ -174,13 +176,13 @@ async function sendMessages(input) {
       }
     }
 
-    input.push(...incoming)
+    messages.push(incoming)
 
     // send messages with tool results
-    await sendMessages(input)
+    await sendMessages(messages)
   } else {
     // no tool calls, just append incoming messages
-    input.push(...incoming)
+    messages.push(incoming)
   }
 }
 
@@ -231,7 +233,7 @@ function writeWithColor() {
 }
 
 export function chat() {
-  /** @type {ResponseInputItem[]} */
+  /** @type {Message[][]} */
   const messages = []
   process.stdin.setEncoding('utf-8')
 
@@ -245,7 +247,7 @@ export function chat() {
       try {
         write(colors.user, 'answer: ', colors.normal)
         outputMode = 'text' // switch to text output mode
-        messages.push({ role: 'user', content: input.trim() })
+        messages.push([{ role: 'user', content: input.trim() }])
         await sendMessages(messages)
       } catch (error) {
         console.error(colors.error, '\n' + error)
diff --git a/bin/types.d.ts b/bin/types.d.ts
index e474c6d..88c6b9b 100644
--- a/bin/types.d.ts
+++ b/bin/types.d.ts
@@ -1,30 +1,17 @@
 // Model Input
-// Based on ResponseCreateParamsStreaming from openai client
-export interface ResponsesInput {
+export interface ChatInput {
   model: string
-  input: ResponseInputItem[] // or string but we always use stateless messages
   instructions?: string // system prompt
-  background?: boolean
-  include?: string[]
+  messages: Message[][]
+  tools?: ResponseTool[]
   reasoning?: {
-    effort?: 'low' | 'medium' | 'high'
+    effort?: 'minimal' | 'low' | 'medium' | 'high'
     summary?: 'auto' | 'concise' | 'detailed'
   }
-  tools?: ResponseTool[]
-  max_output_tokens?: number
   parallel_tool_calls?: boolean
-  previous_response_id?: string
-  // service_tier?: 'auto' | 'default' | 'flex'
-  // store?: boolean // store response for later retrieval
-  temperature?: number // 0..2
-  text?: unknown
-  tool_choice?: 'auto' | 'none' | 'required'
-  top_p?: number // 0..1
-  truncation?: 'auto' | 'disabled'
-  user?: string
 }
 
-export type ResponseInputItem =
+export type Message =
   | EasyInputMessage
   | ResponseFunctionToolCall
   | FunctionCallOutput
diff --git a/package.json b/package.json
index 54943dd..167a95b 100644
--- a/package.json
+++ b/package.json
@@ -56,35 +56,35 @@
   },
   "dependencies": {
     "hightable": "0.20.4",
-    "hyparquet": "1.20.1",
+    "hyparquet": "1.20.2",
     "hyparquet-compressors": "1.1.1",
     "icebird": "0.3.1"
   },
   "devDependencies": {
-    "@eslint/js": "9.38.0",
-    "@storybook/react-vite": "10.0.1",
+    "@eslint/js": "9.39.1",
+    "@storybook/react-vite": "10.0.4",
     "@testing-library/react": "16.3.0",
-    "@types/node": "24.9.2",
+    "@types/node": "24.10.0",
     "@types/react": "19.2.2",
     "@types/react-dom": "19.2.2",
     "@vitejs/plugin-react": "5.1.0",
-    "@vitest/coverage-v8": "4.0.5",
-    "eslint": "9.38.0",
+    "@vitest/coverage-v8": "4.0.7",
+    "eslint": "9.39.1",
     "eslint-plugin-react": "7.37.5",
     "eslint-plugin-react-hooks": "7.0.1",
     "eslint-plugin-react-refresh": "0.4.24",
-    "eslint-plugin-storybook": "10.0.1",
-    "globals": "16.4.0",
-    "jsdom": "27.0.1",
+    "eslint-plugin-storybook": "10.0.4",
+    "globals": "16.5.0",
+    "jsdom": "27.1.0",
     "nodemon": "3.1.10",
     "npm-run-all": "4.1.5",
     "react": "19.2.0",
     "react-dom": "19.2.0",
-    "storybook": "10.0.1",
+    "storybook": "10.0.4",
     "typescript": "5.9.3",
-    "typescript-eslint": "8.46.2",
-    "vite": "7.1.12",
-    "vitest": "4.0.5"
+    "typescript-eslint": "8.46.3",
+    "vite": "7.2.0",
+    "vitest": "4.0.7"
   },
   "peerDependencies": {
     "react": "^18.3.1 || ^19",