fix(api): use camelCase in CallToolResponse and add type discriminators to ContentBlock (#7487)

Co-authored-by: Goose <opensource@block.xyz>
Co-authored-by: Jack Amadeo <jackamadeo@block.xyz>

ui/desktop/src/api/types.gen.ts

@@ -54,9 +54,9 @@ export type CallToolRequest = {
 
 export type CallToolResponse = {
     _meta?: unknown;
-    content: Array<Content>;
-    is_error: boolean;
-    structured_content?: unknown;
+    content: Array<ContentBlock>;
+    isError: boolean;
+    structuredContent?: unknown;
 };
 
 export type ChatRequest = {
@@ -128,7 +128,29 @@ export type ConfirmToolActionRequest = {
     sessionId: string;
 };
 
-export type Content = RawTextContent | RawImageContent | RawEmbeddedResource | RawAudioContent | RawResource;
+export type Content = ({
+    type: 'text';
+} & RawTextContent) | ({
+    type: 'image';
+} & RawImageContent) | ({
+    type: 'resource';
+} & RawEmbeddedResource) | ({
+    type: 'audio';
+} & RawAudioContent) | ({
+    type: 'resource_link';
+} & RawResource);
+
+export type ContentBlock = ({
+    type: 'text';
+} & RawTextContent) | ({
+    type: 'image';
+} & RawImageContent) | ({
+    type: 'resource';
+} & RawEmbeddedResource) | ({
+    type: 'audio';
+} & RawAudioContent) | ({
+    type: 'resource_link';
+} & RawResource);
 
 export type Conversation = Array<Message>;
 
@@ -1112,7 +1134,7 @@ export type RetryConfig = {
     timeout_seconds?: number | null;
 };
 
-export type Role = string;
+export type Role = 'user' | 'assistant';
 
 export type RunNowResponse = {
     session_id: string;
@@ -1317,7 +1339,7 @@ export type SystemNotificationContent = {
 
 export type SystemNotificationType = 'thinkingMessage' | 'inlineMessage' | 'creditsExhausted';
 
-export type TaskSupport = string;
+export type TaskSupport = 'forbidden' | 'optional' | 'required';
 
 export type TelemetryEventRequest = {
     event_name: string;

ui/desktop/src/components/McpApps/McpAppRenderer.tsx

@@ -39,7 +39,6 @@ import {
   McpAppToolCancelled,
   McpAppToolInput,
   McpAppToolInputPartial,
-  McpAppToolResult,
   DimensionLayout,
   OnDisplayModeChange,
   SamplingCreateMessageParams,
@@ -142,7 +141,7 @@ interface McpAppRendererProps {
   sessionId?: string | null;
   toolInput?: McpAppToolInput;
   toolInputPartial?: McpAppToolInputPartial;
-  toolResult?: McpAppToolResult;
+  toolResult?: CallToolResult;
   toolCancelled?: McpAppToolCancelled;
   append?: (text: string) => void;
   displayMode?: GooseDisplayMode;
@@ -505,14 +504,13 @@ export default function McpAppRenderer({
         },
       });
 
-      // rmcp serializes Content with a `type` discriminator via #[serde(tag = "type")].
-      // Our generated TS types don't reflect this, but the wire format matches CallToolResult.content.
       return {
         content: (response.data?.content || []) as unknown as CallToolResult['content'],
-        isError: response.data?.is_error || false,
-        structuredContent: response.data?.structured_content as
+        isError: response.data?.isError || false,
+        structuredContent: response.data?.structuredContent as
           | { [key: string]: unknown }
           | undefined,
+        _meta: response.data?._meta as { [key: string]: unknown } | undefined,
       };
     },
     [sessionId, extensionName]
@@ -685,17 +683,6 @@ export default function McpAppRenderer({
     effectiveDisplayModes,
   ]);
 
-  const appToolResult = useMemo((): CallToolResult | undefined => {
-    if (!toolResult) return undefined;
-    // rmcp serializes Content with a `type` discriminator via #[serde(tag = "type")].
-    // Our generated TS types don't reflect this, but the wire format matches CallToolResult.content.
-    return {
-      content: toolResult.content as unknown as CallToolResult['content'],
-      structuredContent: toolResult.structuredContent as { [key: string]: unknown } | undefined,
-      _meta: toolResult._meta,
-    };
-  }, [toolResult]);
-
   const isToolCancelled = !!toolCancelled;
   const isError = state.status === 'error';
   const isReady = state.status === 'ready';
@@ -736,7 +723,7 @@ export default function McpAppRenderer({
         toolInputPartial={toolInputPartial ? { arguments: toolInputPartial.arguments } : undefined}
         toolCancelled={isToolCancelled}
         hostContext={hostContext}
-        toolResult={appToolResult}
+        toolResult={toolResult}
         onOpenLink={handleOpenLink}
         onMessage={handleMessage}
         onCallTool={handleCallTool}

ui/desktop/src/components/McpApps/types.ts

@@ -4,7 +4,6 @@ import type {
   McpUiToolCancelledNotification,
   McpUiDisplayMode,
 } from '@modelcontextprotocol/ext-apps/app-bridge';
-import type { Content } from '../../api';
 
 /**
  * Space-separated sandbox tokens for iframe permissions.
@@ -37,12 +36,6 @@ export type McpAppToolInputPartial = McpUiToolInputPartialNotification['params']
 
 export type McpAppToolCancelled = McpUiToolCancelledNotification['params'];
 
-export type McpAppToolResult = {
-  content: Content[];
-  structuredContent?: unknown;
-  _meta?: { [key: string]: unknown };
-};
-
 /**
  * Callback fired when the display mode changes, either via user-initiated
  * host-side controls or app-initiated `ui/request-display-mode` changes.

ui/desktop/src/components/ToolCallWithResponse.tsx

@@ -17,7 +17,9 @@ import { ChevronRight, FlaskConical } from 'lucide-react';
 import { TooltipWrapper } from './settings/providers/subcomponents/buttons/TooltipWrapper';
 import MCPUIResourceRenderer from './MCPUIResourceRenderer';
 import { isUIResource } from '@mcp-ui/client';
-import { CallToolResponse, Content, EmbeddedResource } from '../api';
+import type { CallToolResult } from '@modelcontextprotocol/sdk/types.js';
+import { CallToolResponse, ContentBlock, EmbeddedResource } from '../api';
+
 import McpAppRenderer from './McpApps/McpAppRenderer';
 import ToolApprovalButtons from './ToolApprovalButtons';
 
@@ -64,7 +66,7 @@ interface ToolCallWithResponseProps {
   isApprovalClicked?: boolean;
 }
 
-function getToolResultContent(toolResult: Record<string, unknown>): Content[] {
+function getToolResultContent(toolResult: Record<string, unknown>): ContentBlock[] {
   if (toolResult.status !== 'success') {
     return [];
   }
@@ -75,8 +77,11 @@ function getToolResultContent(toolResult: Record<string, unknown>): Content[] {
   });
 }
 
-function isEmbeddedResource(content: Content): content is EmbeddedResource {
-  return 'resource' in content && typeof (content as Record<string, unknown>).resource === 'object';
+function isEmbeddedResource(
+  content: ContentBlock
+): content is EmbeddedResource & { type: 'resource' } {
+  const c = content as Record<string, unknown>;
+  return c.type === 'resource' && typeof c.resource === 'object' && c.resource !== null;
 }
 
 interface McpAppWrapperProps {
@@ -120,7 +125,9 @@ function McpAppWrapper({
 
   const resultWithMeta = toolResponse?.toolResult as ToolResultWithMeta | undefined;
   const toolResult =
-    resultWithMeta?.status === 'success' && resultWithMeta.value ? resultWithMeta.value : undefined;
+    resultWithMeta?.status === 'success' && resultWithMeta.value
+      ? (resultWithMeta.value as unknown as CallToolResult)
+      : undefined;
 
   if (!resourceUri) return null;
   if (requestWithMeta.toolCall.status !== 'success') return null;
@@ -217,13 +224,11 @@ export default function ToolCallWithResponse({
         !hasMcpAppResourceURI &&
         toolResponse?.toolResult &&
         getToolResultContent(toolResponse.toolResult).map((content, index) => {
-          const resourceContent = isEmbeddedResource(content)
-            ? { ...content, type: 'resource' as const }
-            : null;
-          if (resourceContent && isUIResource(resourceContent)) {
+          if (!isEmbeddedResource(content)) return null;
+          if (isUIResource(content)) {
             return (
               <div key={index} className="mt-3">
-                <MCPUIResourceRenderer content={resourceContent} appendPromptToChat={append} />
+                <MCPUIResourceRenderer content={content} appendPromptToChat={append} />
                 <div className="mt-3 p-4 py-3 border border-border-primary rounded-lg bg-background-secondary flex items-center">
                   <FlaskConical className="mr-2" size={20} />
                   <div className="text-sm font-sans">
@@ -857,21 +862,22 @@ interface ToolResultViewProps {
     name: string;
     arguments: Record<string, unknown>;
   };
-  result: Content;
+  result: ContentBlock;
   isStartExpanded: boolean;
 }
 
 function ToolResultView({ toolCall, result, isStartExpanded }: ToolResultViewProps) {
-  const hasText = (c: Content): c is Content & { text: string } =>
+  const hasText = (c: ContentBlock): c is ContentBlock & { text: string } =>
     'text' in c && typeof (c as Record<string, unknown>).text === 'string';
 
-  const hasImage = (c: Content): c is Content & { data: string; mimeType: string } => {
+  const hasImage = (c: ContentBlock): c is ContentBlock & { data: string; mimeType: string } => {
     if (!('data' in c && 'mimeType' in c)) return false;
     const mimeType = (c as Record<string, unknown>).mimeType;
     return typeof mimeType === 'string' && mimeType.startsWith('image');
   };
 
-  const hasResource = (c: Content): c is Content & { resource: unknown } => 'resource' in c;
+  const hasResource = (c: ContentBlock): c is ContentBlock & { resource: unknown } =>
+    'resource' in c;
 
   const wrapMarkdown = (text: string): string => {
     if (