Add stale eve client stream repro

apps/fixtures/README.md

@@ -6,5 +6,6 @@ surface.
 
 - `weather-agent` backs root `pnpm dev`, manual weather-agent smokes, and bundle analysis.
 - `agent-tui-client` backs the non-e2e TUI smoke scripts in `packages/eve/test/tui-client`.
+- `agent-idle-stream-repro` backs the stale eve client stream repro.
 
 When adding fixture behavior, prefer extending an existing fixture unless the new behavior needs incompatible app-level configuration.

apps/fixtures/agent-idle-stream-repro/.gitignore

@@ -0,0 +1,2 @@
+.vercel
+.env*.local

apps/fixtures/agent-idle-stream-repro/agent/agent.ts

@@ -0,0 +1,5 @@
+import { defineAgent } from "eve";
+
+export default defineAgent({
+  model: "openai/gpt-5.4-mini",
+});

apps/fixtures/agent-idle-stream-repro/agent/instructions.md

@@ -0,0 +1 @@
+You are an idle stream repro assistant. Call the `idle_stream_repro` tool when the user asks for it. After the tool returns, reply with the returned label and status.

apps/fixtures/agent-idle-stream-repro/agent/tools/idle_stream_repro.ts

@@ -0,0 +1,20 @@
+import { defineTool } from "eve/tools";
+import { z } from "zod";
+
+export default defineTool({
+  description:
+    "Repro fixture: waits before returning a deterministic image marker. Only call when the user explicitly asks for idle_stream_repro.",
+  inputSchema: z.object({
+    delayMs: z.coerce.number().int().min(0).max(30_000).default(8_000),
+    label: z.string(),
+  }),
+  async execute(input) {
+    await new Promise((resolve) => setTimeout(resolve, input.delayMs));
+
+    return {
+      image: "repro-image.png",
+      label: input.label,
+      status: "completed",
+    };
+  },
+});

apps/fixtures/agent-idle-stream-repro/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "agent-idle-stream-repro",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "eve dev",
+    "build": "eve build",
+    "start": "eve start",
+    "typecheck": "tsc --noEmit -p tsconfig.json"
+  },
+  "dependencies": {
+    "eve": "workspace:*",
+    "zod": "catalog:"
+  }
+}

apps/fixtures/agent-idle-stream-repro/tsconfig.json

@@ -0,0 +1,27 @@
+{
+  "$schema": "https://json.schemastore.org/tsconfig",
+  "compilerOptions": {
+    "target": "ES2024",
+    "lib": ["ES2024"],
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "moduleDetection": "force",
+    "verbatimModuleSyntax": true,
+    "noEmit": true,
+    "erasableSyntaxOnly": true,
+    "strict": true,
+    "isolatedModules": true,
+    "forceConsistentCasingInFileNames": true,
+    "noUncheckedIndexedAccess": true,
+    "noFallthroughCasesInSwitch": true,
+    "noImplicitOverride": true,
+    "useUnknownInCatchVariables": true,
+    "resolveJsonModule": true,
+    "skipLibCheck": true,
+    "types": ["node"],
+    "allowJs": true,
+    "rootDir": "."
+  },
+  "include": ["agent/**/*", ".eve/**/*.d.ts"],
+  "exclude": ["node_modules", "dist", "build", ".turbo", ".vercel"]
+}

packages/eve/src/internal/testing/scenario-apps/idle-stream-repro.ts

@@ -0,0 +1,79 @@
+import type { ScenarioAppDescriptor } from "#internal/testing/scenario-app.js";
+
+const IDLE_STREAM_REPRO_TSCONFIG_SOURCE = `${JSON.stringify(
+  {
+    $schema: "https://json.schemastore.org/tsconfig",
+    compilerOptions: {
+      allowJs: true,
+      erasableSyntaxOnly: true,
+      forceConsistentCasingInFileNames: true,
+      isolatedModules: true,
+      lib: ["ES2024"],
+      module: "NodeNext",
+      moduleDetection: "force",
+      moduleResolution: "NodeNext",
+      noEmit: true,
+      noFallthroughCasesInSwitch: true,
+      noImplicitOverride: true,
+      noUncheckedIndexedAccess: true,
+      resolveJsonModule: true,
+      rootDir: ".",
+      skipLibCheck: true,
+      strict: true,
+      target: "ES2024",
+      types: ["node"],
+      useUnknownInCatchVariables: true,
+      verbatimModuleSyntax: true,
+    },
+    exclude: ["node_modules", "dist", "build", ".turbo", ".vercel"],
+    include: ["agent/**/*"],
+  },
+  null,
+  2,
+)}\n`;
+
+/**
+ * Scenario-tier eve app for reproducing a stale client stream after an inline
+ * tool starts. The tool waits before returning, which gives a proxy enough
+ * time to stop forwarding the live response while durable tail events remain
+ * replayable from the session stream route.
+ */
+export const IDLE_STREAM_REPRO_DESCRIPTOR: ScenarioAppDescriptor = {
+  dependencies: {
+    zod: "^4.3.6",
+  },
+  files: {
+    "agent/agent.ts": `import { defineAgent } from "eve";
+
+export default defineAgent({
+  model: "openai/gpt-5.4-mini",
+});
+`,
+    "agent/instructions.md": `You are an idle stream repro assistant. Call the \`idle_stream_repro\` tool when the user asks for it. After the tool returns, reply with the returned label and status.
+`,
+    "agent/tools/idle_stream_repro.ts": `import { defineTool } from "eve/tools";
+import { z } from "zod";
+
+export default defineTool({
+  description:
+    "Repro fixture: waits before returning a deterministic image marker. Only call when the user explicitly asks for idle_stream_repro.",
+  inputSchema: z.object({
+    delayMs: z.coerce.number().int().min(0).max(30_000).default(8_000),
+    label: z.string(),
+  }),
+  async execute(input) {
+    await new Promise((resolve) => setTimeout(resolve, input.delayMs));
+
+    return {
+      image: "repro-image.png",
+      label: input.label,
+      status: "completed",
+    };
+  },
+});
+`,
+    "tsconfig.json": IDLE_STREAM_REPRO_TSCONFIG_SOURCE,
+  },
+  installDependencies: true,
+  name: "agent-idle-stream-repro",
+};

packages/eve/src/internal/testing/scenario-apps/index.ts

@@ -2,6 +2,7 @@ export { CUSTOM_CHANNEL_PORTABILITY_DESCRIPTOR } from "#internal/testing/scenari
 export { DISCORD_ROUTE_PORTABILITY_DESCRIPTOR } from "#internal/testing/scenario-apps/discord-route-portability.js";
 export { EXTENSION_AGENT_DESCRIPTOR } from "#internal/testing/scenario-apps/extension-agent.js";
 export { GITHUB_ROUTE_PORTABILITY_DESCRIPTOR } from "#internal/testing/scenario-apps/github-route-portability.js";
+export { IDLE_STREAM_REPRO_DESCRIPTOR } from "#internal/testing/scenario-apps/idle-stream-repro.js";
 export { EVE_ROUTE_PORTABILITY_DESCRIPTOR } from "#internal/testing/scenario-apps/eve-route-portability.js";
 export { SANDBOX_BUNDLING_DESCRIPTOR } from "#internal/testing/scenario-apps/sandbox-bundling.js";
 export { SANDBOX_WORKSPACES_DESCRIPTOR } from "#internal/testing/scenario-apps/sandbox-workspaces.js";