diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/package.json b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/package.json
new file mode 100644
index 000000000000..60b3b4027272
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/package.json
@@ -0,0 +1,41 @@
+{
+  "name": "cloudflare-pi-durable",
+  "version": "0.0.0",
+  "private": true,
+  "scripts": {
+    "dev": "vite dev",
+    "build": "vite build",
+    "preview": "vite preview --port 38789",
+    "typecheck": "tsc --noEmit",
+    "test:build": "pnpm install && pnpm build",
+    "test:build-latest": "pnpm install && pnpm add agents@latest @earendil-works/pi-durable@latest @earendil-works/pi-ai@latest && pnpm build",
+    "test:assert": "playwright test"
+  },
+  "dependencies": {
+    "@earendil-works/pi-ai": "1.0.0",
+    "@earendil-works/pi-durable": "1.0.0",
+    "@sentry/cloudflare": "file:../../packed/sentry-cloudflare-packed.tgz",
+    "agents": "0.26.0"
+  },
+  "devDependencies": {
+    "@cloudflare/vite-plugin": "1.57.2",
+    "@cloudflare/workers-types": "^4.20260426.0",
+    "@playwright/test": "~1.63.0",
+    "@sentry-internal/test-utils": "link:../../../test-utils",
+    "typescript": "^5.5.2",
+    "vite": "7.3.5",
+    "wrangler": "^4.136.2"
+  },
+  "volta": {
+    "extends": "../../package.json"
+  },
+  "sentryTest": {
+    "optional": true,
+    "optionalVariants": [
+      {
+        "build-command": "pnpm test:build-latest",
+        "label": "cloudflare-pi-durable (latest)"
+      }
+    ]
+  }
+}
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/playwright.config.ts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/playwright.config.ts
new file mode 100644
index 000000000000..1b9be61d8261
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/playwright.config.ts
@@ -0,0 +1,13 @@
+import { getPlaywrightConfig } from '@sentry-internal/test-utils';
+
+const config = getPlaywrightConfig(
+  {
+    startCommand: 'pnpm preview',
+    port: 38789,
+  },
+  // Each test drives real OpenRouter tool-calling turns, and one resets the Durable Object mid-run,
+  // which does not fit the default 30s timeout when the provider is slow.
+  { timeout: 120_000 },
+);
+
+export default config;
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/assistant.ts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/assistant.ts
new file mode 100644
index 000000000000..bd0d25a8c5b3
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/assistant.ts
@@ -0,0 +1,96 @@
+import { Type } from '@earendil-works/pi-ai';
+import { createModels } from '@earendil-works/pi-ai/models';
+import { openrouterProvider } from '@earendil-works/pi-ai/providers/openrouter';
+import { createRegistry, defineExtension, defineTool, Harness, section } from '@earendil-works/pi-durable';
+import * as Sentry from '@sentry/cloudflare';
+import { Agent } from 'agents';
+import { PiHarness } from 'agents/harness/pi';
+
+/**
+ * pi-durable hosted by the Agents SDK `PiHarness`: pi keeps its state in this object's SQLite
+ * database, and the harness reopens pi when the object restarts. Nothing wires Sentry into
+ * pi-durable by hand, the Vite plugin injects the channel into `Harness.open()`.
+ */
+export class Assistant extends Agent<Env> {
+  public registry = createRegistry();
+
+  public harness = new PiHarness({
+    harness: ({ storage, context }) => {
+      // pi-ai reads provider keys from `process.env` by default, so the Worker hands over its secret.
+      const models = createModels({
+        authContext: {
+          env: async name => (name === 'OPENROUTER_API_KEY' ? this.env.E2E_OPENROUTER_API_KEY : undefined),
+          fileExists: async () => false,
+        },
+      });
+      models.setProvider(openrouterProvider());
+      return Harness.open(storage, { models, registry: this.registry }, context);
+    },
+    defaults: { model: { provider: 'openrouter', id: 'anthropic/claude-haiku-4.5' } },
+  });
+
+  public constructor(ctx: DurableObjectState, env: Env) {
+    super(ctx, env);
+    this.registry.install(
+      defineExtension({
+        name: 'e2e',
+        sections: [
+          section('preamble', () => 'You are a test assistant. Use the tools exactly as asked. Keep answers short.', {
+            tag: false,
+          }),
+        ],
+        tools: [
+          defineTool({
+            name: 'get_weather',
+            description: 'Get the current weather for a city.',
+            parameters: Type.Object({ city: Type.String() }),
+            // The manual span should nest under the SDK's `execute_tool` span.
+            execute: async args =>
+              Sentry.startSpan({ name: 'resolve-weather', attributes: { 'weather.city': args.city } }, () => ({
+                content: [{ type: 'text', text: `It is 21 degrees and sunny in ${args.city}.` }],
+              })),
+          }),
+          defineTool({
+            name: 'fail_now',
+            description: 'Always throws an error. Call this when the user asks to trigger a failure.',
+            parameters: Type.Object({}),
+            execute: async () => {
+              throw new Error('Intentional pi-durable tool failure');
+            },
+          }),
+          defineTool({
+            name: 'crash_once',
+            description: 'Runs one step of a job. Call this when the user asks for crash_once.',
+            parameters: Type.Object({ job: Type.String() }),
+            // Replay-safe, so pi-durable reruns the call after the reset instead of failing it.
+            replay: 'safe',
+            execute: async args => {
+              const marker = `crashed:${args.job}`;
+              if (await this.ctx.storage.get(marker)) {
+                return { content: [{ type: 'text', text: `Step of job ${args.job} completed.` }] };
+              }
+              await this.ctx.storage.put(marker, true);
+              await this.ctx.storage.sync();
+              // Drops the object mid-call, like an eviction. The next request starts it again.
+              this.ctx.abort('crash_once resets the Durable Object');
+              throw new Error('The Durable Object did not reset');
+            },
+          }),
+        ],
+      }),
+    );
+    this.lifecycle.use(this.harness);
+  }
+
+  public async onRequest(request: Request): Promise<Response> {
+    if (request.method === 'GET') {
+      const operationId = new URL(request.url).searchParams.get('operation') ?? '';
+      const { status, reason, text } = await this.harness.wait(operationId);
+      return Response.json({ status, reason, text });
+    }
+
+    const { message, operationId } = await request.json<{ message: string; operationId?: string }>();
+    const { status, reason, text } = await this.harness.prompt(message, { operationId });
+    return Response.json({ status, reason, text });
+  }
+}
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/env.d.ts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/env.d.ts
new file mode 100644
index 000000000000..a088008cd966
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/env.d.ts
@@ -0,0 +1,9 @@
+declare namespace Cloudflare {
+  interface Env {
+    E2E_TEST_DSN: string;
+    E2E_OPENROUTER_API_KEY: string;
+    Assistant: DurableObjectNamespace;
+  }
+}
+
+interface Env extends Cloudflare.Env {}
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/index.ts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/index.ts
new file mode 100644
index 000000000000..756f31007b6b
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/index.ts
@@ -0,0 +1,9 @@
+import { routeAgentRequest } from 'agents';
+
+export { Assistant } from './assistant';
+
+export default {
+  async fetch(request, env): Promise<Response> {
+    return (await routeAgentRequest(request, env)) ?? new Response('Not found', { status: 404 });
+  },
+} satisfies ExportedHandler<Env>;
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/instrument.server.ts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/instrument.server.ts
new file mode 100644
index 000000000000..4bd8e8b9fdc0
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/src/instrument.server.ts
@@ -0,0 +1,10 @@
+import { defineCloudflareOptions } from '@sentry/cloudflare';
+
+// The Sentry Vite plugin picks this file up by convention, next to the worker entry named in
+// wrangler's `main`, and hands its default export to `withSentry`.
+export default defineCloudflareOptions((env: Env) => ({
+  dsn: env.E2E_TEST_DSN,
+  environment: 'qa',
+  tunnel: 'http://localhost:3031/',
+  tracesSampleRate: 1.0,
+}));
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/start-event-proxy.mjs b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/start-event-proxy.mjs
new file mode 100644
index 000000000000..bdcf0b3d4465
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/start-event-proxy.mjs
@@ -0,0 +1,6 @@
+import { startEventProxyServer } from '@sentry-internal/test-utils';
+
+startEventProxyServer({
+  port: 3031,
+  proxyServerName: 'cloudflare-pi-durable',
+});
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tests/pi-durable.test.ts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tests/pi-durable.test.ts
new file mode 100644
index 000000000000..3f0afd2a2c19
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tests/pi-durable.test.ts
@@ -0,0 +1,133 @@
+import { expect, test } from '@playwright/test';
+import { collectStreamedSpans, getSpanOp, waitForError } from '@sentry-internal/test-utils';
+import { newAgentId, prompt, submitPrompt, waitForOperation } from './utils';
+
+const APP = 'cloudflare-pi-durable';
+
+test('traces a PiHarness prompt as invoke_agent with chat, execute_tool and provider spans', async ({ baseURL }) => {
+  // A run is its own trace, and its `invoke_agent` segment ends last. Only this test calls get_weather.
+  const spansPromise = collectStreamedSpans(
+    APP,
+    spansOfTrace =>
+      spansOfTrace.some(span => span.is_segment && getSpanOp(span) === 'gen_ai.invoke_agent') &&
+      spansOfTrace.some(span => span.attributes['gen_ai.tool.name']?.value === 'get_weather'),
+  );
+
+  const answer = await prompt(
+    baseURL!,
+    newAgentId('weather'),
+    'What is the weather in Vienna? Use the get_weather tool.',
+  );
+  expect(answer.status, answer.reason).toBe('done');
+
+  const spans = await spansPromise;
+  const agent = spans.find(span => span.is_segment)!;
+  const chats = spans.filter(span => getSpanOp(span) === 'gen_ai.chat');
+  // The manual span of the tool is the one way to pick the call that ran, should the model call twice.
+  const manualSpan = spans.find(span => span.name === 'resolve-weather')!;
+  const tool = spans.find(span => span.span_id === manualSpan.parent_span_id)!;
+  const providerCalls = spans.filter(span => getSpanOp(span) === 'http.client');
+
+  expect(agent.attributes['sentry.origin']?.value).toBe('auto.ai.pi_durable');
+  // The PiHarness root session is pi conversation 1, in a Harness of its own per Durable Object.
+  expect(agent.attributes['gen_ai.conversation.id']?.value).toMatch(/^[0-9a-f]{32}:1$/);
+  // The request that submitted the prompt is a trace of its own: the scheduler runs the work.
+  expect(spans.some(span => getSpanOp(span) === 'http.server')).toBe(false);
+  // pi-durable keeps its state in the `pi_` tables of `PiHarness`, whose statements start no span.
+  expect(spans.filter(span => getSpanOp(span) === 'db.query' && /\bpi_/.test(String(span.name)))).toEqual([]);
+  // pi-ai sends the requests through `@anthropic-ai/sdk`, whose own integration must stay out so
+  // each request is reported once.
+  expect(spans.filter(span => String(span.attributes['sentry.origin']?.value).startsWith('auto.ai.'))).toEqual(
+    spans.filter(span => span.attributes['sentry.origin']?.value === 'auto.ai.pi_durable'),
+  );
+
+  // One tool-calling response, then the answer.
+  expect(chats.length).toBeGreaterThanOrEqual(2);
+  for (const chat of chats) {
+    expect(chat.parent_span_id).toBe(agent.span_id);
+    expect(chat.attributes['gen_ai.provider.name']?.value).toBe('openrouter');
+    expect(chat.attributes['gen_ai.request.model']?.value).toBe('anthropic/claude-haiku-4.5');
+    expect(chat.attributes['gen_ai.conversation.id']?.value).toBe(agent.attributes['gen_ai.conversation.id']?.value);
+    // pi-durable retries a provider error inside the run; such a request has no usage and no HTTP span
+    // of its own to assert on.
+    if (chat.status === 'ok') {
+      expect(typeof chat.attributes['gen_ai.usage.input_tokens']?.value).toBe('number');
+      expect(typeof chat.attributes['gen_ai.usage.output_tokens']?.value).toBe('number');
+      expect(providerCalls.some(providerCall => providerCall.parent_span_id === chat.span_id)).toBe(true);
+    }
+  }
+
+  expect(tool.attributes['gen_ai.tool.name']?.value).toBe('get_weather');
+  expect(tool.parent_span_id).toBe(agent.span_id);
+  expect(tool.status).toBe('ok');
+  expect(tool.attributes['gen_ai.tool.call.arguments']?.value).toContain('Vienna');
+  expect(tool.attributes['gen_ai.tool.call.result']?.value).toContain('21 degrees and sunny in');
+
+  // The provider's HTTP calls nest inside the `chat` span that sent them.
+  expect(providerCalls.length).toBeGreaterThan(0);
+  for (const providerCall of providerCalls) {
+    expect(chats.map(chat => chat.span_id)).toContain(providerCall.parent_span_id);
+    expect(providerCall.attributes['server.address']?.value).toBe('openrouter.ai');
+  }
+});
+
+test('reports a throwing tool as an error on its execute_tool span', async ({ baseURL }) => {
+  const errorPromise = waitForError(
+    APP,
+    event => event.exception?.values?.[0]?.value === 'Intentional pi-durable tool failure',
+  );
+  const spansPromise = collectStreamedSpans(
+    APP,
+    spansOfTrace =>
+      spansOfTrace.some(span => span.is_segment && getSpanOp(span) === 'gen_ai.invoke_agent') &&
+      spansOfTrace.some(span => span.attributes['gen_ai.tool.name']?.value === 'fail_now'),
+  );
+
+  const answer = await prompt(baseURL!, newAgentId('fail'), 'Call the fail_now tool, then tell me what happened.');
+  expect(answer.status, answer.reason).toBe('done');
+
+  const [error, spans] = await Promise.all([errorPromise, spansPromise]);
+  // The error is reported on the span of the call that threw.
+  const tool = spans.find(span => span.span_id === error.contexts?.trace?.span_id)!;
+
+  expect(tool.attributes['gen_ai.tool.name']?.value).toBe('fail_now');
+  expect(tool.status).toBe('error');
+  expect(tool.trace_id).toBe(error.contexts?.trace?.trace_id);
+  expect(error.exception?.values?.[0]?.mechanism).toEqual({ type: 'auto.ai.pi_durable', handled: true });
+});
+
+test('resumes a run in a new trace after the Durable Object resets during a tool call', async ({ baseURL }) => {
+  const agentId = newAgentId('reset');
+  const operationId = crypto.randomUUID();
+  // The tool span of the reset object never ends, so a finished `crash_once` span can only come
+  // from the rerun after the restart.
+  const spansPromise = collectStreamedSpans(
+    APP,
+    spansOfTrace =>
+      spansOfTrace.some(span => span.is_segment && getSpanOp(span) === 'gen_ai.invoke_agent') &&
+      spansOfTrace.some(span => span.attributes['gen_ai.tool.name']?.value === 'crash_once' && span.status === 'ok'),
+  );
+
+  // The reset fails the request that submitted the prompt, but pi has stored the input already.
+  await submitPrompt(
+    baseURL!,
+    agentId,
+    'Run the crash_once tool for job "nightly", then reply with the word DONE.',
+    operationId,
+  );
+  const answer = await waitForOperation(baseURL!, agentId, operationId);
+  expect(answer.status, answer.reason).toBe('done');
+
+  const spans = await spansPromise;
+  const agent = spans.find(span => span.is_segment)!;
+  const tool = spans.find(span => span.attributes['gen_ai.tool.name']?.value === 'crash_once')!;
+  const chats = spans.filter(span => getSpanOp(span) === 'gen_ai.chat');
+  const finalAnswer = chats.find(span => span.attributes['gen_ai.response.finish_reasons']?.value === '["stop"]');
+
+  expect(getSpanOp(agent)).toBe('gen_ai.invoke_agent');
+  expect(tool.parent_span_id).toBe(agent.span_id);
+  expect(finalAnswer?.parent_span_id).toBe(agent.span_id);
+  // The request that called the tool ran before the reset, so this trace starts with the rerun of the
+  // tool. A run that never reset would start with that request.
+  expect(chats.every(chat => chat.start_timestamp >= tool.start_timestamp)).toBe(true);
+});
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tests/utils.ts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tests/utils.ts
new file mode 100644
index 000000000000..0e23ca86301e
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tests/utils.ts
@@ -0,0 +1,38 @@
+import { expect } from '@playwright/test';
+
+export type Operation = { status: string; reason?: string; text?: string };
+
+/**
+ * A Durable Object name nothing has used yet. The name is the `:name` path segment
+ * `routeAgentRequest` maps to an object, so each test gets its own SQLite database and pi Harness.
+ */
+export function newAgentId(prefix: string): string {
+  return `${prefix}-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+}
+
+/** Submit a prompt to the root session. The response arrives once pi settles it. */
+export function submitPrompt(
+  baseURL: string,
+  agentId: string,
+  message: string,
+  operationId?: string,
+): Promise<Response> {
+  return fetch(`${baseURL}/agents/assistant/${agentId}`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ message, operationId }),
+  });
+}
+
+export async function prompt(baseURL: string, agentId: string, message: string): Promise<Operation> {
+  const res = await submitPrompt(baseURL, agentId, message);
+  expect(res.status).toBe(200);
+  return (await res.json()) as Operation;
+}
+
+/** Wait until pi settles an operation. The request starts the object again if it was reset. */
+export async function waitForOperation(baseURL: string, agentId: string, operationId: string): Promise<Operation> {
+  const res = await fetch(`${baseURL}/agents/assistant/${agentId}?operation=${operationId}`);
+  expect(res.status).toBe(200);
+  return (await res.json()) as Operation;
+}
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tsconfig.json b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tsconfig.json
new file mode 100644
index 000000000000..40863136da68
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/tsconfig.json
@@ -0,0 +1,20 @@
+{
+  "compilerOptions": {
+    "target": "es2022",
+    "lib": ["es2022"],
+    "module": "es2022",
+    "moduleResolution": "Bundler",
+    "resolveJsonModule": true,
+    "allowJs": true,
+    "checkJs": false,
+    "noEmit": true,
+    "isolatedModules": true,
+    "allowSyntheticDefaultImports": true,
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "types": ["@cloudflare/workers-types"]
+  },
+  "exclude": ["tests"],
+  "include": ["src/**/*.ts"]
+}
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/vite.config.mts b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/vite.config.mts
new file mode 100644
index 000000000000..005f4448f6cb
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/vite.config.mts
@@ -0,0 +1,7 @@
+import { cloudflare } from '@cloudflare/vite-plugin';
+import { sentryCloudflareVitePlugin } from '@sentry/cloudflare/vite';
+import { defineConfig } from 'vite';
+
+export default defineConfig({
+  plugins: [cloudflare(), sentryCloudflareVitePlugin()],
+});
diff --git a/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/wrangler.toml b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/wrangler.toml
new file mode 100644
index 000000000000..1b2207bd862f
--- /dev/null
+++ b/dev-packages/e2e-tests/test-applications/cloudflare-pi-durable/wrangler.toml
@@ -0,0 +1,18 @@
+#:schema node_modules/wrangler/config-schema.json
+name = "cloudflare-pi-durable"
+main = "src/index.ts"
+compatibility_date = "2026-09-15"
+compatibility_flags = ["nodejs_compat"]
+
+# `vite preview` takes no `--var` flag, so the secrets are declared here and read from
+# the process environment the Playwright web server inherits.
+[secrets]
+required = ["E2E_TEST_DSN", "E2E_OPENROUTER_API_KEY"]
+
+[[durable_objects.bindings]]
+name = "Assistant"
+class_name = "Assistant"
+
+[[migrations]]
+tag = "v1"
+new_sqlite_classes = ["Assistant"]