feat(chat): expose get_diff tool in Ask agent

Register get_diff in the Ask agent toolset and render its output in the details panel so chat workflows can compare refs directly.

Made-with: Cursor

Author: msukkari

packages/web/src/features/chat/agent.ts

@@ -271,7 +271,7 @@ const createPrompt = ({
         The user has explicitly selected the following repositories for analysis:
         ${repos.map(repo => `- ${repo}`).join('\n')}
 
-        When calling tools that accept a \`repo\` parameter (e.g. \`read_file\`, \`list_commits\`, \`list_tree\`, \`grep\`), use these repository names exactly as listed above, including the full host prefix (e.g. \`github.com/org/repo\`).
+        When calling tools that accept a \`repo\` parameter (e.g. \`read_file\`, \`list_commits\`, \`list_tree\`, \`get_diff\`, \`grep\`), use these repository names exactly as listed above, including the full host prefix (e.g. \`github.com/org/repo\`).
 
         When using \`grep\` to search across ALL selected repositories (e.g. "which repos have X?"), omit the \`repo\` parameter entirely — the tool will automatically search across all selected repositories in a single call. Do NOT call \`grep\` once per repository when a single broad search would suffice.
         </selected_repositories>

packages/web/src/features/chat/components/chatThread/detailsCard.tsx

@@ -19,6 +19,7 @@ import { FindSymbolDefinitionsToolComponent } from './tools/findSymbolDefinition
 import { FindSymbolReferencesToolComponent } from './tools/findSymbolReferencesToolComponent';
 import { GlobToolComponent } from './tools/globToolComponent';
 import { GrepToolComponent } from './tools/grepToolComponent';
+import { GetDiffToolComponent } from './tools/getDiffToolComponent';
 import { ListCommitsToolComponent } from './tools/listCommitsToolComponent';
 import { ListReposToolComponent } from './tools/listReposToolComponent';
 import { ListTreeToolComponent } from './tools/listTreeToolComponent';
@@ -289,6 +290,15 @@ export const StepPartRenderer = ({ part }: { part: SBChatMessagePart }) => {
                     {(output) => <ListCommitsToolComponent {...output} />}
                 </ToolOutputGuard>
             )
+        case 'tool-get_diff':
+            return (
+                <ToolOutputGuard
+                    part={part}
+                    loadingText="Comparing revisions..."
+                >
+                    {(output) => <GetDiffToolComponent {...output} />}
+                </ToolOutputGuard>
+            )
         case 'tool-list_tree':
             return (
                 <ToolOutputGuard

packages/web/src/features/chat/components/chatThread/tools/getDiffToolComponent.tsx

@@ -0,0 +1,30 @@
+'use client';
+
+import { Separator } from '@/components/ui/separator';
+import { GetDiffMetadata, ToolResult } from '@/features/tools';
+
+export const GetDiffToolComponent = ({ metadata }: ToolResult<GetDiffMetadata>) => {
+    const fileCount = metadata.files.length;
+
+    return (
+        <div className="flex items-center gap-2 select-none cursor-default text-sm text-muted-foreground">
+            <span className="flex-shrink-0">Compared</span>
+            <span className="text-xs font-mono bg-muted px-1.5 py-0.5 rounded text-foreground">
+                {metadata.base}
+            </span>
+            <span className="flex-shrink-0">to</span>
+            <span className="text-xs font-mono bg-muted px-1.5 py-0.5 rounded text-foreground">
+                {metadata.head}
+            </span>
+            <span className="flex-shrink-0">in</span>
+            <span className="text-xs font-mono bg-muted px-1.5 py-0.5 rounded text-foreground truncate">
+                {metadata.repo}
+            </span>
+            <span className="flex-1" />
+            <span className="text-xs flex-shrink-0">
+                {fileCount} changed {fileCount === 1 ? 'file' : 'files'}
+            </span>
+            <Separator orientation="vertical" className="h-3 flex-shrink-0" />
+        </div>
+    );
+};

packages/web/src/features/chat/tools.ts

@@ -3,6 +3,7 @@ import {
     readFileDefinition,
     listCommitsDefinition,
     listReposDefinition,
+    getDiffDefinition,
     grepDefinition,
     globDefinition,
     findSymbolReferencesDefinition,
@@ -17,6 +18,7 @@ export const createTools = (context: ToolContext) => ({
     [readFileDefinition.name]: toVercelAITool(readFileDefinition, context),
     [listCommitsDefinition.name]: toVercelAITool(listCommitsDefinition, context),
     [listReposDefinition.name]: toVercelAITool(listReposDefinition, context),
+    [getDiffDefinition.name]: toVercelAITool(getDiffDefinition, context),
     [grepDefinition.name]: toVercelAITool(grepDefinition, context),
     [globDefinition.name]: toVercelAITool(globDefinition, context),
     [findSymbolReferencesDefinition.name]: toVercelAITool(findSymbolReferencesDefinition, context),
@@ -27,6 +29,7 @@ export const createTools = (context: ToolContext) => ({
 export type ReadFileToolUIPart = ToolUIPart<{ read_file: SBChatMessageToolTypes['read_file'] }>;
 export type ListCommitsToolUIPart = ToolUIPart<{ list_commits: SBChatMessageToolTypes['list_commits'] }>;
 export type ListReposToolUIPart = ToolUIPart<{ list_repos: SBChatMessageToolTypes['list_repos'] }>;
+export type GetDiffToolUIPart = ToolUIPart<{ get_diff: SBChatMessageToolTypes['get_diff'] }>;
 export type GrepToolUIPart = ToolUIPart<{ grep: SBChatMessageToolTypes['grep'] }>;
 export type GlobToolUIPart = ToolUIPart<{ glob: SBChatMessageToolTypes['glob'] }>;
 export type FindSymbolReferencesToolUIPart = ToolUIPart<{ find_symbol_references: SBChatMessageToolTypes['find_symbol_references'] }>;