Add voice SSE endpoint and thread summary tool to MCP agent (#1884)

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## Description

Please provide a clear description of your changes.

---

## Type of Change

Please delete options that are not relevant.

- [ ] 🐛 Bug fix (non-breaking change which fixes an issue)
- [ ] ✨ New feature (non-breaking change which adds functionality)
- [ ] 💥 Breaking change (fix or feature with breaking changes)
- [ ] 📝 Documentation update
- [ ] 🎨 UI/UX improvement
- [ ] 🔒 Security enhancement
- [ ] ⚡ Performance improvement

## Areas Affected

Please check all that apply:

- [ ] Email Integration (Gmail, IMAP, etc.)
- [ ] User Interface/Experience
- [ ] Authentication/Authorization
- [ ] Data Storage/Management
- [ ] API Endpoints
- [ ] Documentation
- [ ] Testing Infrastructure
- [ ] Development Workflow
- [ ] Deployment/Infrastructure

## Testing Done

Describe the tests you've done:

- [ ] Unit tests added/updated
- [ ] Integration tests added/updated
- [ ] Manual testing performed
- [ ] Cross-browser testing (if UI changes)
- [ ] Mobile responsiveness verified (if UI changes)

## Security Considerations

For changes involving data or authentication:

- [ ] No sensitive data is exposed
- [ ] Authentication checks are in place
- [ ] Input validation is implemented
- [ ] Rate limiting is considered (if applicable)

## Checklist

- [ ] I have read the [CONTRIBUTING](https://github.com/Mail-0/Zero/blob/staging/.github/CONTRIBUTING.md) document
- [ ] My code follows the project's style guidelines
- [ ] I have performed a self-review of my code
- [ ] I have commented my code, particularly in complex areas
- [ ] I have updated the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix/feature works
- [ ] All tests pass locally
- [ ] Any dependent changes are merged and published

## Additional Notes

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## Screenshots/Recordings

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---

_By submitting this pull request, I confirm that my contribution is made under the terms of the project's license._

    
<!-- This is an auto-generated description by cubic. -->
---

## Summary by cubic
Added a new voice SSE endpoint for authenticated callers and a thread summary tool to the MCP agent for summarizing email threads.

- **New Features**
  - Added /vsse SSE endpoint with authentication for voice integrations.
  - Added getThreadSummary tool to MCP agent to return concise summaries of email threads.

<!-- End of auto-generated description by cubic. -->



<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

* **New Features**
  * Added a new endpoint at `/vsse` with enhanced multi-step authorization and user verification.
  * Introduced a tool to generate AI-powered summaries of email threads, providing concise overviews along with key thread details.

* **Improvements**
  * Updated thread listings to display sender information in the format: name <email>.
  * Improved thread retrieval logic for more accurate results.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: MrgSub

apps/server/src/main.ts

@@ -668,6 +668,36 @@ const app = new Hono<HonoContext>()
     },
     { replaceRequest: false },
   )
+  .mount(
+    '/vsse',
+    async (request, env, ctx) => {
+      const authBearer = request.headers.get('Authorization');
+      const callerId = request.headers.get('X-Caller');
+      if (!callerId) {
+        return new Response('Unauthorized', { status: 401 });
+      }
+      if (!authBearer) {
+        console.log('No auth provided');
+        return new Response('Unauthorized', { status: 401 });
+      }
+      if (authBearer !== env.VOICE_SECRET) {
+        return new Response('Unauthorized', { status: 401 });
+      }
+      const { db, conn } = createDb(env.HYPERDRIVE.connectionString);
+      const foundUser = await db.query.user.findFirst({
+        where: and(eq(user.phoneNumber, callerId), eq(user.phoneNumberVerified, true)),
+      });
+      await conn.end();
+      if (!foundUser) {
+        return new Response('Unauthorized', { status: 401 });
+      }
+      ctx.props = {
+        userId: foundUser.id,
+      };
+      return ZeroMCP.serveSSE('/vsse', { binding: 'ZERO_MCP' }).fetch(request, env, ctx);
+    },
+    { replaceRequest: false },
+  )
   .mount(
     '/mcp/thinking/sse',
     async (request, env, ctx) => {

apps/server/src/routes/agent/mcp.ts

@@ -64,6 +64,75 @@ export class ZeroMCP extends McpAgent<typeof env, Record<string, unknown>, { use
       },
     );
 
+    this.server.registerTool(
+      'getThreadSummary',
+      {
+        description: 'Get the summary of a specific email thread',
+        inputSchema: {
+          id: z.string(),
+        },
+      },
+      async (s) => {
+        if (!this.activeConnectionId) {
+          return {
+            content: [
+              {
+                type: 'text' as const,
+                text: 'No active connection',
+              },
+            ],
+          };
+        }
+        const response = await env.VECTORIZE.getByIds([s.id]);
+        const driver = await getZeroAgent(this.activeConnectionId);
+        const thread = await driver.getThread(s.id);
+        if (response.length && response?.[0]?.metadata?.['summary'] && thread?.latest?.subject) {
+          const result = response[0].metadata as { summary: string; connection: string };
+          if (result.connection !== this.activeConnectionId) {
+            return {
+              content: [
+                {
+                  type: 'text' as const,
+                  text: 'No summary found for this connection',
+                },
+              ],
+            };
+          }
+          const shortResponse = await env.AI.run('@cf/facebook/bart-large-cnn', {
+            input_text: result.summary,
+          });
+          return {
+            content: [
+              {
+                type: 'text' as const,
+                text: shortResponse.summary as string,
+              },
+              {
+                type: 'text' as const,
+                text: `Subject: ${thread.latest?.subject}`,
+              },
+              {
+                type: 'text' as const,
+                text: `Sender: ${thread.latest?.sender.name} <${thread.latest?.sender.email}>`,
+              },
+              {
+                type: 'text' as const,
+                text: `Date: ${thread.latest?.receivedOn}`,
+              },
+            ],
+          };
+        }
+        return {
+          content: [
+            {
+              type: 'text' as const,
+              text: 'No summary found',
+            },
+          ],
+        };
+      },
+    );
+
     this.server.registerTool(
       'getActiveConnection',
       {
@@ -249,7 +318,7 @@ export class ZeroMCP extends McpAgent<typeof env, Record<string, unknown>, { use
         },
       },
       async (s) => {
-        const result = await agent.listThreads({
+        const result = await agent.rawListThreads({
           folder: s.folder,
           query: s.query,
           maxResults: s.maxResults,
@@ -266,7 +335,7 @@ export class ZeroMCP extends McpAgent<typeof env, Record<string, unknown>, { use
               },
               {
                 type: 'text' as const,
-                text: `Latest Message Sender: ${loadedThread.latest?.sender}`,
+                text: `Latest Message Sender: ${thread.latest?.sender.name} <${thread.latest?.sender.email}>`,
               },
             ];
           }),