tui: show streaming tokens-per-second in real-time during model responses

Previously, users only saw tok/s metrics after a message completed. Now

the TUI displays live streaming speed that updates throughout the response,

giving immediate feedback on model performance.

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -1281,22 +1281,30 @@ function AssistantMessage(props: { index: number; message: AssistantMessage; par
   })
 
   const stats = createMemo(() => {
-    if (!final() || !props.message.time.completed) return null
+    // if (!final() || !props.message.time.completed) return null
 
     const list = messages()
-    let tokens = props.message.tokens?.output || 0
+    const stats = {
+      duration: 0,
+      tps: [] as number[],
+    }
 
-    for (let i = props.index - 1; i >= 0; i--) {
+    for (let i = props.index; i >= 0; i--) {
       const msg = list[i]
+
       if (msg.id === props.message.parentID && msg.role === "user") {
-        if (!msg.time?.created) return null
+        stats.duration = (props.message.time.completed ?? Date.now()) - msg.time.created
         return {
-          duration: props.message.time.completed - msg.time.created,
-          tokens,
+          duration: (props.message.time.completed ?? Date.now()) - msg.time.created,
+          tps: stats.tps.reduce((sum, x) => sum + x, 0) / stats.tps.length,
         }
       }
       if (msg.role === "assistant") {
-        tokens += msg.tokens?.output || 0
+        if (msg.tokens.output && msg.time.started && msg.time.streamed) {
+          const duration = msg.time.streamed - msg.time.started
+          const tps = msg.tokens.output / (duration / 1000)
+          stats.tps.push(tps)
+        }
       }
     }
 
@@ -1355,7 +1363,7 @@ function AssistantMessage(props: { index: number; message: AssistantMessage; par
                   <span style={{ fg: theme.textMuted }}>
                     {" "}
                     · {Locale.duration(s().duration)}
-                    <Show when={s().tokens > 0}> · {(s().tokens / (s().duration / 1000)).toFixed(1)} tok/s</Show>
+                    <Show when={s().tps > 0}> · {s().tps.toFixed(0)} tok/s</Show>
                   </span>
                 )}
               </Show>

packages/opencode/src/session/message-v2.ts

@@ -392,6 +392,8 @@ export namespace MessageV2 {
     role: z.literal("assistant"),
     time: z.object({
       created: z.number(),
+      started: z.number().optional(),
+      streamed: z.number().optional(),
       completed: z.number().optional(),
     }),
     error: z

packages/opencode/src/session/processor.ts

@@ -57,6 +57,8 @@ export namespace SessionProcessor {
               switch (value.type) {
                 case "start":
                   SessionStatus.set(input.sessionID, { type: "busy" })
+                  input.assistantMessage.time.started = Date.now()
+                  await Session.updateMessage(input.assistantMessage)
                   break
 
                 case "reasoning-start":
@@ -334,12 +336,16 @@ export namespace SessionProcessor {
                     await Session.updatePart(currentText)
                   }
                   currentText = undefined
+                  input.assistantMessage.time.streamed = Date.now()
+                  await Session.updateMessage(input.assistantMessage)
                   break
 
                 case "finish":
                   break
 
                 default:
+                    type: value.type,
+                  })
                   log.info("unhandled", {
                     ...value,
                   })

packages/sdk/js/src/v2/gen/types.gen.ts

@@ -207,6 +207,8 @@ export type AssistantMessage = {
   role: "assistant"
   time: {
     created: number
+    started?: number
+    streamed?: number
     completed?: number
   }
   error?: