feat(mcp): the server gives hosts its title and icon (#3095)

`initialize` now answers with serverInfo.title "CodeGraph" and one
embedded SVG in serverInfo.icons, on the direct path and from the
daemon proxy, which share SERVER_INFO. A host that shows them can list
CodeGraph by name and logo instead of a plain `codegraph`.

The icon is the site's favicon (site/public/favicon.svg) on a light
tile. The bare mark is dark ink on nothing, and on a dark background
only its two white dots show (checked in a browser at 16 to 64 px). It
is spelled out in the source instead of as a base64 blob, so a reader
can see it is three lines and three circles.

`sizes` is left off the icon on purpose. It's optional and says nothing
about an SVG, and @modelcontextprotocol/sdk 1.18.0 typed it as a string
where the spec settled on an array, so a host on that SDK would fail the
whole handshake on the array form.

Left out from PR #879, on purpose: `_meta.icons` and icons on every
tool. Those add about 1 KB per tool to each tools/list for no host we
could find that needs them; Codex reads serverInfo.icons.

What each host shows, read from its source or binary on 2026-10-30:
- Codex: keeps serverInfo.title and .icons and sends them to its app
  (McpServerStatus.serverInfo); the terminal UI's /mcp doesn't read them.
- opencode: reads serverInfo.title into the server list; its dialogs
  still print the config name, and it doesn't read icons.
- Claude Code 2.1.296: connects fine with these fields (checked with
  `claude mcp list` in a sandbox home), and no read of title or icons
  turns up in its binary, so it keeps showing the config name.
- Cursor: closed source and not on this machine. Its docs mention no
  server title or icon, so this is unverified.

Validation: 3 tests in mcp-initialize fail on main's session and pass
here; mcp-daemon now pins the proxy's serverInfo to the same object.

Reimplements PR #879 by @fedosov.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -20,6 +20,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ### New Features
 
 - `codegraph files --format package` and `codegraph_files` with `format: "package"` now list a project's files by the package that owns them, the nearest `package.json` or `composer.json` above each file that names one, so a monorepo splits into its workspace members with no setup and files nothing claims get a section of their own (#1871). Thanks @LuisAlbertoMK.
+- CodeGraph's MCP server now gives agents and editors its display name and icon, so one that shows them, like the Codex app, lists CodeGraph by name and logo instead of a plain `codegraph`. Thanks @fedosov.
 
 ### Fixes
 

__tests__/mcp-daemon.test.ts

@@ -43,6 +43,7 @@ import { getDaemonSocketPath } from '../src/mcp/daemon-paths';
 import { CodeGraphPackageVersion } from '../src/mcp/version';
 import { once } from 'events';
 import { WASM_RUNTIME_FLAGS } from '../src/extraction/wasm-runtime-flags';
+import { SERVER_INFO } from '../src/mcp/session';
 import { recordSpawns, removeSpawnLog, settleLosingCandidates } from './daemon-candidates';
 
 const BIN = path.resolve(__dirname, '../dist/bin/codegraph.js');
@@ -282,7 +283,7 @@ describe('Shared MCP daemon (issue #411)', () => {
     servers.push(first);
     sendInitialize(first.child, `file://${tempDir}`, 1);
     const firstResp = await waitFor(() => findResponse(first.stdout, 1), 10000);
-    expect(firstResp.result.serverInfo.name).toBe('codegraph');
+    expect(firstResp.result.serverInfo).toEqual(SERVER_INFO);
 
     // The launcher is a PROXY (not the daemon itself) — that's the detach fix.
     await waitFor(() => first.stderr.some((l) => l.includes('Attached to shared daemon')), 8000);

__tests__/mcp-initialize.test.ts

@@ -18,9 +18,23 @@ import * as os from 'os';
 import { CodeGraph } from '../src';
 import { once } from 'events';
 import { WASM_RUNTIME_FLAGS } from '../src/extraction/wasm-runtime-flags';
+import { SERVER_INFO } from '../src/mcp/session';
 
 const BIN = path.resolve(__dirname, '../dist/bin/codegraph.js');
 
+/** The fields of `serverInfo` a host can draw. */
+function expectServerBranding(info: { title?: string; icons?: Array<Record<string, unknown>> }): void {
+  expect(info.title).toBe('CodeGraph');
+  expect(info.icons).toHaveLength(1);
+  const icon = info.icons![0]!;
+  expect(icon.mimeType).toBe('image/svg+xml');
+  expect(String(icon.src)).toMatch(/^data:image\/svg\+xml;base64,/);
+  const svg = Buffer.from(String(icon.src).split(',')[1]!, 'base64').toString('utf8');
+  expect(svg).toMatch(/^<svg\b/);
+  // `sizes` is left off on purpose: see SERVER_INFO.
+  expect(Object.keys(icon).sort()).toEqual(['mimeType', 'src']);
+}
+
 function spawnServer(cwd: string): ChildProcessWithoutNullStreams {
   return spawn(process.execPath, [...WASM_RUNTIME_FLAGS, BIN, 'serve', '--mcp'], {
     cwd,
@@ -121,6 +135,21 @@ async function removeWhenReleased(dir: string, timeoutMs = 5000): Promise<void>
   }
 }
 
+describe('MCP server title and icon', () => {
+  it('names the server and carries an icon no host has to fetch', () => {
+    expectServerBranding(SERVER_INFO);
+  });
+
+  it('keeps the machine name hosts key on, and nothing but shapes in the icon', () => {
+    expect(SERVER_INFO.name).toBe('codegraph');
+    const svg = Buffer.from(SERVER_INFO.icons[0]!.src.split(',')[1]!, 'base64').toString('utf8');
+    expect(svg.match(/<\w+/g)?.sort()).toEqual(
+      ['<circle', '<circle', '<circle', '<line', '<line', '<line', '<rect', '<svg'],
+    );
+    expect(svg).not.toMatch(/href|url\(|on\w+=|style/i);
+  });
+});
+
 describe('MCP initialize handshake (issue #172)', () => {
   let tempDir: string;
   let child: ChildProcessWithoutNullStreams | null = null;
@@ -179,6 +208,7 @@ describe('MCP initialize handshake (issue #172)', () => {
     const json = JSON.parse(response.text);
     expect(json.id).toBe(0);
     expect(json.result.serverInfo.name).toBe('codegraph');
+    expectServerBranding(json.result.serverInfo);
   }, 20000);
 
   it('answers resources/list and prompts/list with empty lists, not -32601 (issue #621)', async () => {

src/mcp/session.ts

@@ -23,15 +23,40 @@ import { getTelemetry, ClientInfo } from '../telemetry';
 import { getUpdateNotice } from '../upgrade/update-check';
 import { ExploreSessionState } from './explore-session-state';
 
+/**
+ * The site's favicon on a light tile: the bare mark is dark ink on nothing,
+ * which a dark UI loses. Written out rather than as base64 so a reader can see
+ * it is two lines of shapes and nothing else.
+ */
+const SERVER_ICON_SVG =
+  '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32" fill="none" stroke="#16150f" stroke-width="2">' +
+  '<rect width="32" height="32" rx="6" fill="#f7f6f2" stroke="none"/>' +
+  '<line x1="16" y1="8" x2="8" y2="23"/><line x1="16" y1="8" x2="24" y2="23"/><line x1="8" y1="23" x2="24" y2="23"/>' +
+  '<circle cx="16" cy="8" r="3.4" fill="#16150f"/><circle cx="8" cy="23" r="3.4" fill="#f7f6f2"/><circle cx="24" cy="23" r="3.4" fill="#f7f6f2"/>' +
+  '</svg>';
+
 /**
  * MCP Server Info — kept on the session because some clients log it. The
  * version tracks the real package version (was a hard-coded '0.1.0').
+ *
+ * `title` and `icons` are what a host may show in place of `name`. They are
+ * newer than the protocol version this server claims, so a host that doesn't
+ * know them passes over them. The icon has no `sizes`: it is optional and says
+ * nothing about an SVG, and a host on an SDK that typed it as a string, as 1.18
+ * did, would fail the whole handshake on the array the spec settled on.
  */
 // Exported so the proxy can answer `initialize` locally with the IDENTICAL
 // payload the daemon would send — no drift between the two handshake paths.
 export const SERVER_INFO = {
   name: 'codegraph',
+  title: 'CodeGraph',
   version: CodeGraphPackageVersion,
+  icons: [
+    {
+      src: `data:image/svg+xml;base64,${Buffer.from(SERVER_ICON_SVG).toString('base64')}`,
+      mimeType: 'image/svg+xml',
+    },
+  ],
 };
 
 /**