diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c8cc7ccb..00ca623e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -49,14 +49,17 @@ jobs:
           cache-dependency-path: package-lock.json
 
       - name: Install dependencies
-        run: npm ci --workspace server
+        run: npm ci --workspace shared && npm ci --workspace server
 
-      - name: Build (tsc + tsc-alias -> dist)
+      - name: Build shared
+        run: npm run build --workspace=shared
+
+      - name: Build server (tsc -> dist)
         run: cd server && npm run build
 
       - name: Typecheck (informational)
-        # Legacy code still has pre-existing type errors; this surfaces them
-        # without blocking the migration. Ratchet to blocking once cleaned up.
+        # Pre-existing type errors in the NestJS rewrite; surfaces them without
+        # blocking CI. Ratchet to blocking once the legacy code is cleaned up.
         continue-on-error: true
         run: cd server && npm run typecheck
 
@@ -85,7 +88,10 @@ jobs:
           cache-dependency-path: package-lock.json
 
       - name: Install dependencies
-        run: npm ci --workspace client
+        run: npm ci --workspace shared && npm ci --workspace client
+
+      - name: Build shared
+        run: npm run build --workspace=shared
 
       - name: Run tests
         run: cd client && npm run test:coverage
diff --git a/server/vitest.config.ts b/server/vitest.config.ts
index ef65960f..660e71f3 100644
--- a/server/vitest.config.ts
+++ b/server/vitest.config.ts
@@ -38,20 +38,23 @@ export default defineConfig({
   },
   resolve: {
     alias: {
+      // MCP SDK's exports map uses extension-less wildcard targets that neither
+      // Node nor Vite can resolve. Point directly at the CJS dist files.
+      // Paths are relative to the monorepo root (packages are hoisted there).
       '@modelcontextprotocol/sdk/server/mcp': new URL(
-          './node_modules/@modelcontextprotocol/sdk/dist/cjs/server/mcp.js',
+          '../node_modules/@modelcontextprotocol/sdk/dist/cjs/server/mcp.js',
           import.meta.url
       ).pathname,
       '@modelcontextprotocol/sdk/server/streamableHttp': new URL(
-          './node_modules/@modelcontextprotocol/sdk/dist/cjs/server/streamableHttp.js',
+          '../node_modules/@modelcontextprotocol/sdk/dist/cjs/server/streamableHttp.js',
           import.meta.url
       ).pathname,
       '@modelcontextprotocol/sdk/inMemory': new URL(
-          './node_modules/@modelcontextprotocol/sdk/dist/cjs/inMemory.js',
+          '../node_modules/@modelcontextprotocol/sdk/dist/cjs/inMemory.js',
           import.meta.url
       ).pathname,
       '@modelcontextprotocol/sdk/client/index': new URL(
-          './node_modules/@modelcontextprotocol/sdk/dist/cjs/client/index.js',
+          '../node_modules/@modelcontextprotocol/sdk/dist/cjs/client/index.js',
           import.meta.url
       ).pathname,
     },