Require tool part ids for tool-call rendering and caching

Rebind permissions from callID to part id when parts arrive.

packages/ui/src/components/markdown.tsx

@@ -35,7 +35,10 @@ export function Markdown(props: MarkdownProps) {
     const dark = Boolean(props.isDark)
     const themeKey = dark ? "dark" : "light"
     const highlightEnabled = !props.disableHighlight
-    const partId = typeof part.id === "string" && part.id.length > 0 ? part.id : "__anonymous__"
+    const partId = typeof part.id === "string" && part.id.length > 0 ? part.id : ""
+    if (!partId) {
+      throw new Error("Markdown rendering requires a part id")
+    }
     const versionKey = typeof part.version === "number" ? String(part.version) : ""
     const cacheKey = makeMarkdownCacheKey(partId, themeKey, highlightEnabled, versionKey)
 

packages/ui/src/components/message-block.tsx

@@ -453,7 +453,7 @@ export default function MessageBlock(props: MessageBlockProps) {
                         </div>
                         <ToolCall
                           toolCall={toolItem.toolPart}
-                          toolCallId={toolItem.key}
+                          toolCallId={toolItem.toolPart.id}
                           messageId={toolItem.messageId}
                           messageVersion={toolItem.messageVersion}
                           partVersion={toolItem.partVersion}

packages/ui/src/components/tool-call.tsx

@@ -222,7 +222,13 @@ export default function ToolCall(props: ToolCallProps) {
   const { isDark } = useTheme()
   const toolCallMemo = createMemo(() => props.toolCall)
   const toolName = createMemo(() => toolCallMemo()?.tool || "")
-  const toolCallIdentifier = createMemo(() => toolCallMemo()?.callID || props.toolCallId || toolCallMemo()?.id || "")
+  const toolCallIdentifier = createMemo(() => {
+    const partId = toolCallMemo()?.id
+    if (!partId) {
+      throw new Error("Tool call requires a part id")
+    }
+    return partId
+  })
   const toolState = createMemo(() => toolCallMemo()?.state)
 
   const cacheContext = createMemo(() => ({
@@ -695,7 +701,11 @@ export default function ToolCall(props: ToolCallProps) {
       )
     }
 
-    const markdownPart: TextPart = { type: "text", text: options.content, version: props.partVersion }
+    const partId = toolCallMemo()?.id
+    if (!partId) {
+      throw new Error("Tool call markdown requires a part id")
+    }
+    const markdownPart: TextPart = { id: partId, type: "text", text: options.content, version: props.partVersion }
     const cached = markdownCache.get<RenderCache>()
     if (cached) {
       markdownPart.renderCache = cached

packages/ui/src/stores/message-v2/bridge.ts

@@ -112,27 +112,62 @@ function extractPermissionMessageId(permission: Permission): string | undefined
 }
 
 function extractPermissionPartId(permission: Permission): string | undefined {
+  const metadata = (permission as any).metadata || {}
+  return (
+    (permission as any).partID ||
+    (permission as any).partId ||
+    metadata.partID ||
+    metadata.partId ||
+    undefined
+  )
+}
+
+function extractPermissionCallId(permission: Permission): string | undefined {
   const metadata = (permission as any).metadata || {}
   return (
     (permission as any).callID ||
     (permission as any).callId ||
     (permission as any).toolCallID ||
     (permission as any).toolCallId ||
-    metadata.partId ||
-    metadata.partID ||
     metadata.callID ||
     metadata.callId ||
     undefined
   )
 }
 
+function resolvePartIdFromCallId(store: ReturnType<typeof messageStoreBus.getOrCreate>, messageId?: string, callId?: string): string | undefined {
+  if (!messageId || !callId) return undefined
+  const record = store.getMessage(messageId)
+  if (!record) return undefined
+  for (const partId of record.partIds) {
+    const part = record.parts[partId]?.data
+    if (!part || part.type !== "tool") continue
+    const toolCallId =
+      (part as any).callID ??
+      (part as any).callId ??
+      (part as any).toolCallID ??
+      (part as any).toolCallId ??
+      undefined
+    if (toolCallId === callId && typeof part.id === "string" && part.id.length > 0) {
+      return part.id
+    }
+  }
+  return undefined
+}
+
 export function upsertPermissionV2(instanceId: string, permission: Permission): void {
   if (!permission) return
   const store = messageStoreBus.getOrCreate(instanceId)
+  const messageId = extractPermissionMessageId(permission)
+  let partId = extractPermissionPartId(permission)
+  if (!partId) {
+    const callId = extractPermissionCallId(permission)
+    partId = resolvePartIdFromCallId(store, messageId, callId)
+  }
   store.upsertPermission({
     permission,
-    messageId: extractPermissionMessageId(permission),
+    messageId,
-    partId: extractPermissionPartId(permission),
+    partId,
     enqueuedAt: (permission as any).time?.created ?? Date.now(),
   })
 }

packages/ui/src/stores/message-v2/instance-store.ts

@@ -51,16 +51,8 @@ function ensurePartId(messageId: string, part: ClientPart, index: number): strin
     return part.id
   }
 
-  const toolCallId =
+  if (part.type === "tool") {
-    (part as any).callID ??
+    throw new Error("Tool part missing id")
-    (part as any).callId ??
-    (part as any).toolCallID ??
-    (part as any).toolCallId ??
-    undefined
-
-  if (part.type === "tool" && typeof toolCallId === "string" && toolCallId.length > 0) {
-    part.id = toolCallId
-    return toolCallId
   }
 
   const fallbackId = `${messageId}-part-${index}`
@@ -504,6 +496,50 @@ export function createInstanceMessageStore(instanceId: string, hooks?: MessageSt
     })
   }
 
+  function rebindPermissionForPart(messageId: string, partId: string, part: ClientPart) {
+    if (!messageId || !partId || part.type !== "tool") {
+      return
+    }
+
+    const toolCallId =
+      (part as any).callID ??
+      (part as any).callId ??
+      (part as any).toolCallID ??
+      (part as any).toolCallId ??
+      undefined
+    if (!toolCallId) {
+      return
+    }
+
+    setState(
+      "permissions",
+      "byMessage",
+      messageId,
+      produce((draft) => {
+        if (!draft) return
+        const existing = draft[partId]
+        for (const [key, entry] of Object.entries(draft)) {
+          if (!entry || entry.partId) continue
+          const permissionCallId =
+            (entry.permission as any).callID ??
+            (entry.permission as any).callId ??
+            (entry.permission as any).toolCallID ??
+            (entry.permission as any).toolCallId ??
+            (entry.permission as any).metadata?.callID ??
+            (entry.permission as any).metadata?.callId ??
+            undefined
+          if (permissionCallId !== toolCallId) continue
+          if (!existing || existing.permission.id === entry.permission.id) {
+            entry.partId = partId
+            draft[partId] = entry
+            delete draft[key]
+          }
+          break
+        }
+      }),
+    )
+  }
+
   function applyPartUpdate(input: PartUpdateInput) {
     const message = state.messages[input.messageId]
     if (!message) {
@@ -535,6 +571,8 @@ export function createInstanceMessageStore(instanceId: string, hooks?: MessageSt
       }),
     )
 
+    rebindPermissionForPart(input.messageId, partId, cloned)
+
     if (isCompletedTodoPart(cloned)) {
       recordLatestTodoSnapshot(message.sessionId, {
         messageId: input.messageId,
@@ -740,7 +778,7 @@ export function createInstanceMessageStore(instanceId: string, hooks?: MessageSt
 
   function upsertPermission(entry: PermissionEntry) {
     const messageKey = entry.messageId ?? "__global__"
-    const partKey = entry.partId ?? "__global__"
+    const partKey = entry.partId ?? entry.permission?.id ?? "__global__"
 
     setState(
       "permissions",

packages/ui/src/stores/message-v2/normalizers.ts

@@ -26,35 +26,13 @@ function decodeTextSegment(segment: any): any {
   return segment
 }
 
-function deriveToolPartId(part: any): string | undefined {
-  if (!part || typeof part !== "object") {
-    return undefined
-  }
-  if (part.type !== "tool") {
-    return undefined
-  }
-  const callId =
-    part.callID ??
-    part.callId ??
-    part.toolCallID ??
-    part.toolCallId ??
-    undefined
-  if (typeof callId === "string" && callId.length > 0) {
-    return callId
-  }
-  return undefined
-}
-
 export function normalizeMessagePart(part: any): any {
   if (!part || typeof part !== "object") {
     return part
   }
 
-  if ((typeof part.id !== "string" || part.id.length === 0) && part.type === "tool") {
+  if (part.type === "tool" && (typeof part.id !== "string" || part.id.length === 0)) {
-    const inferredId = deriveToolPartId(part)
+    throw new Error("Tool part missing id")
-    if (inferredId) {
-      part = { ...part, id: inferredId }
-    }
   }
 
   if (part.type !== "text") {