diff --git a/dev-packages/bundler-tests/package.json b/dev-packages/bundler-tests/package.json
index 1210085b32ef..36502c297b61 100644
--- a/dev-packages/bundler-tests/package.json
+++ b/dev-packages/bundler-tests/package.json
@@ -19,6 +19,22 @@
     "vitest": "^4.1.11",
     "webpack": "^5.0.0"
   },
+  "devDependencies": {
+    "@sentry/astro": "11.9.0",
+    "@sentry/bun": "11.9.0",
+    "@sentry/cloudflare": "11.9.0",
+    "@sentry/deno": "11.9.0",
+    "@sentry/nextjs": "11.9.0",
+    "@sentry/node": "11.9.0",
+    "@sentry/nuxt": "11.9.0",
+    "@sentry/react-router": "11.9.0",
+    "@sentry/remix": "11.9.0",
+    "@sentry/solidstart": "11.9.0",
+    "@sentry/sveltekit": "11.9.0",
+    "@sentry/tanstackstart-react": "11.9.0",
+    "@sentry/vercel-edge": "11.9.0",
+    "@vercel/nft": "^1.11.0"
+  },
   "volta": {
     "extends": "../../package.json"
   },
diff --git a/dev-packages/bundler-tests/tests/runtime-entries.test.ts b/dev-packages/bundler-tests/tests/runtime-entries.test.ts
new file mode 100644
index 000000000000..4006b833bc70
--- /dev/null
+++ b/dev-packages/bundler-tests/tests/runtime-entries.test.ts
@@ -0,0 +1,197 @@
+import { describe, expect, test } from 'vitest';
+import * as path from 'node:path';
+import * as fs from 'node:fs';
+import { fileURLToPath } from 'node:url';
+
+import { nodeFileTrace, resolve } from '@vercel/nft';
+
+/**
+ * Server runtime entries must not reach build-time tooling. When they do,
+ * the tooling ends up in server bundles and traced outputs (Next standalone,
+ * Nitro, workerd, ...), where it breaks in a different way for each
+ * consumer. `@vercel/nft` is the tracer that Next standalone and the Vercel
+ * adapters use, so it reports what those consumers would ship.
+ */
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const ROOT_DIR = path.join(__dirname, '../../..');
+const FIXTURE_DIR = path.join(__dirname, '..', 'dist', 'runtime-entries');
+
+const BUILD_TIME_PATTERNS: RegExp[] = [
+  /(^|\/)packages\/bundler-plugins\//,
+  /(^|\/)node_modules\/@sentry\/bundler-plugins(\/|$)/,
+  /(^|\/)packages\/server-utils\/build\/[^/]+\/orchestrion\/bundler\//,
+  /(^|\/)node_modules\/(vite|webpack|rollup|esbuild|oxc-parser)\//,
+  /(^|\/)node_modules\/@(babel|rollup|oxc-parser)\//,
+  /\.wasm$/,
+];
+
+/**
+ * These root entries also re-export config-time code (`sentryAstro`,
+ * `withSentry`). They must keep it until v12 for backwards compatibility.
+ */
+const KNOWN_VIOLATIONS = new Set(['@sentry/astro', '@sentry/solidstart']);
+
+type Format = 'esm' | 'cjs';
+
+interface Case {
+  specifier: string;
+  conditions: string[];
+  formats: Format[];
+}
+
+const NODE = ['node'];
+const WORKERD = ['workerd', 'worker'];
+const BOTH: Format[] = ['esm', 'cjs'];
+const ESM: Format[] = ['esm'];
+
+const CASES: Case[] = [
+  { specifier: '@sentry/node', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/node/import', conditions: NODE, formats: ESM },
+  { specifier: '@sentry/bun', conditions: ['bun', 'node'], formats: BOTH },
+  { specifier: '@sentry/deno', conditions: ['deno', 'node'], formats: ESM },
+  { specifier: '@sentry/vercel-edge', conditions: ['edge-light'], formats: BOTH },
+  { specifier: '@sentry/cloudflare', conditions: WORKERD, formats: BOTH },
+  { specifier: '@sentry/cloudflare', conditions: [...WORKERD, 'development'], formats: BOTH },
+
+  { specifier: '@sentry/nextjs', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/nextjs', conditions: ['edge-light'], formats: BOTH },
+  { specifier: '@sentry/nextjs', conditions: WORKERD, formats: BOTH },
+  { specifier: '@sentry/nextjs/cloudflare', conditions: WORKERD, formats: BOTH },
+  { specifier: '@sentry/nextjs/import', conditions: NODE, formats: ESM },
+  { specifier: '@sentry/nextjs/async-storage-shim', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/nextjs/orchestrion-runtime/index', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/nextjs/orchestrion-runtime/register', conditions: NODE, formats: BOTH },
+
+  { specifier: '@sentry/nuxt', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/nuxt/module/plugins', conditions: NODE, formats: ESM },
+
+  { specifier: '@sentry/sveltekit', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/sveltekit', conditions: WORKERD, formats: BOTH },
+  { specifier: '@sentry/sveltekit', conditions: ['worker'], formats: BOTH },
+
+  { specifier: '@sentry/astro', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/astro/middleware', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/astro/import', conditions: NODE, formats: ESM },
+
+  { specifier: '@sentry/react-router', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/react-router', conditions: WORKERD, formats: BOTH },
+  { specifier: '@sentry/react-router/cloudflare', conditions: WORKERD, formats: BOTH },
+
+  { specifier: '@sentry/remix', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/remix', conditions: ['worker'], formats: BOTH },
+  { specifier: '@sentry/remix/cloudflare', conditions: WORKERD, formats: BOTH },
+  { specifier: '@sentry/remix/import', conditions: NODE, formats: ESM },
+
+  { specifier: '@sentry/solidstart', conditions: NODE, formats: BOTH },
+
+  { specifier: '@sentry/tanstackstart-react', conditions: NODE, formats: BOTH },
+  { specifier: '@sentry/tanstackstart-react/import', conditions: NODE, formats: ESM },
+];
+
+function writeFixture(specifier: string, conditions: string[], format: Format): string {
+  fs.mkdirSync(FIXTURE_DIR, { recursive: true });
+  const name = `${specifier.replace(/[@/]/g, '_')}-${conditions.join('_')}.${format === 'esm' ? 'mjs' : 'cjs'}`;
+  const file = path.join(FIXTURE_DIR, name);
+  fs.writeFileSync(file, format === 'esm' ? `import '${specifier}';\n` : `require('${specifier}');\n`);
+  return file;
+}
+
+function isBuildTime(file: string): boolean {
+  return BUILD_TIME_PATTERNS.some(pattern => pattern.test(file));
+}
+
+type Reasons = Awaited<ReturnType<typeof nodeFileTrace>>['reasons'];
+
+// Most entries share `@sentry/node` and its dependencies, so sharing the
+// file and analysis cache saves most of the work.
+const traceCache = {};
+
+/** The shortest import chain from `entry` to `file`, both relative to `ROOT_DIR`. */
+function importChain(reasons: Reasons, entry: string, file: string): string[] {
+  const importedBy = new Map<string, string>([[file, file]]);
+  const queue = [file];
+  while (queue.length) {
+    const current = queue.shift() as string;
+    if (current === entry) {
+      const chain = [current];
+      for (let link = current; link !== file;) {
+        link = importedBy.get(link) as string;
+        chain.push(link);
+      }
+      return chain;
+    }
+    for (const parent of reasons.get(current)?.parents ?? []) {
+      if (!importedBy.has(parent)) {
+        importedBy.set(parent, current);
+        queue.push(parent);
+      }
+    }
+  }
+  return [file];
+}
+
+/**
+ * Each place where a runtime module imports a build-time module, as the
+ * import chain from the entry.
+ */
+async function findBuildTimeImports(fixture: string, conditions: string[]): Promise<string[]> {
+  const imports: [importer: string, file: string][] = [];
+
+  const { fileList, reasons } = await nodeFileTrace([fixture], {
+    base: ROOT_DIR,
+    conditions,
+    cache: traceCache,
+    // A dynamic `fs` path in config code makes nft glob the whole repo.
+    // That is slow and finds user files, not package code.
+    analysis: { emitGlobs: false },
+    // Stop at the first build-time module, instead of tracing all of Vite
+    // or Babel. `.wasm` files are assets, so they stay in the trace with
+    // their importer.
+    ignore: file => isBuildTime(file) && !file.endsWith('.wasm'),
+    async resolve(id, parent, job, cjsResolve) {
+      const resolved = await resolve(id, parent, job, cjsResolve);
+      for (const file of [resolved].flat()) {
+        if (isBuildTime(file)) {
+          imports.push([path.relative(ROOT_DIR, parent), path.relative(ROOT_DIR, file)]);
+        }
+      }
+      return resolved;
+    },
+  });
+
+  for (const file of fileList) {
+    if (file.endsWith('.wasm')) {
+      for (const parent of reasons.get(file)?.parents ?? []) {
+        imports.push([parent, file]);
+      }
+    }
+  }
+
+  const entry = path.relative(ROOT_DIR, fixture);
+  const violations = imports.map(([importer, file]) =>
+    importChain(reasons, entry, importer).concat(file).join('\n  -> '),
+  );
+  return [...new Set(violations)].sort();
+}
+
+describe('server runtime entries do not reach build-time tooling', () => {
+  for (const { specifier, conditions, formats } of CASES) {
+    for (const format of formats) {
+      const name = `${specifier} (${format}, conditions: ${conditions.join(', ')})`;
+
+      if (KNOWN_VIOLATIONS.has(specifier)) {
+        test(`${name} is a known violation`, async () => {
+          const violations = await findBuildTimeImports(writeFixture(specifier, conditions, format), conditions);
+          // Remove the entry from KNOWN_VIOLATIONS when this fails.
+          expect(violations).not.toEqual([]);
+        });
+      } else {
+        test(name, async () => {
+          const violations = await findBuildTimeImports(writeFixture(specifier, conditions, format), conditions);
+          expect(violations).toEqual([]);
+        });
+      }
+    }
+  }
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 617e70dc091a..9d9050c1f98e 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -432,6 +432,49 @@ importers:
       webpack:
         specifier: ^5.0.0
         version: 5.104.1(clean-css@5.2.2)(cssnano@7.1.9(postcss@8.5.31))(csso@5.0.5)(esbuild@0.28.1)(html-minifier-terser@6.1.0)(lightningcss@1.33.0)(postcss@8.5.31)(uglify-js@3.13.3)
+    devDependencies:
+      '@sentry/astro':
+        specifier: 11.9.0
+        version: link:../../packages/astro
+      '@sentry/bun':
+        specifier: 11.9.0
+        version: link:../../packages/bun
+      '@sentry/cloudflare':
+        specifier: 11.9.0
+        version: link:../../packages/cloudflare
+      '@sentry/deno':
+        specifier: 11.9.0
+        version: link:../../packages/deno
+      '@sentry/nextjs':
+        specifier: 11.9.0
+        version: link:../../packages/nextjs
+      '@sentry/node':
+        specifier: 11.9.0
+        version: link:../../packages/node
+      '@sentry/nuxt':
+        specifier: 11.9.0
+        version: link:../../packages/nuxt
+      '@sentry/react-router':
+        specifier: 11.9.0
+        version: link:../../packages/react-router
+      '@sentry/remix':
+        specifier: 11.9.0
+        version: link:../../packages/remix
+      '@sentry/solidstart':
+        specifier: 11.9.0
+        version: link:../../packages/solidstart
+      '@sentry/sveltekit':
+        specifier: 11.9.0
+        version: link:../../packages/sveltekit
+      '@sentry/tanstackstart-react':
+        specifier: 11.9.0
+        version: link:../../packages/tanstackstart-react
+      '@sentry/vercel-edge':
+        specifier: 11.9.0
+        version: link:../../packages/vercel-edge
+      '@vercel/nft':
+        specifier: ^1.11.0
+        version: 1.11.0(encoding@0.1.13)(rollup@4.62.3)(supports-color@10.0.0)
 
   dev-packages/clear-cache-gh-action:
     dependencies: