diff --git a/src/commands/sessions.e2e.test.ts b/src/commands/sessions.e2e.test.ts
index 61f89889022..4c82b36b9c3 100644
--- a/src/commands/sessions.e2e.test.ts
+++ b/src/commands/sessions.e2e.test.ts
@@ -1,54 +1,19 @@
 import fs from "node:fs";
-import os from "node:os";
-import path from "node:path";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import {
+  makeRuntime,
+  mockSessionsConfig,
+  runSessionsJson,
+  writeStore,
+} from "./sessions.test-helpers.js";
 
 // Disable colors for deterministic snapshots.
 process.env.FORCE_COLOR = "0";
 
-vi.mock("../config/config.js", async (importOriginal) => {
-  const actual = await importOriginal<typeof import("../config/config.js")>();
-  return {
-    ...actual,
-    loadConfig: () => ({
-      agents: {
-        defaults: {
-          model: { primary: "pi:opus" },
-          models: { "pi:opus": {} },
-          contextTokens: 32000,
-        },
-      },
-    }),
-  };
-});
+mockSessionsConfig();
 
 import { sessionsCommand } from "./sessions.js";
 
-const makeRuntime = () => {
-  const logs: string[] = [];
-  return {
-    runtime: {
-      log: (msg: unknown) => logs.push(String(msg)),
-      error: (msg: unknown) => {
-        throw new Error(String(msg));
-      },
-      exit: (code: number) => {
-        throw new Error(`exit ${code}`);
-      },
-    },
-    logs,
-  } as const;
-};
-
-const writeStore = (data: unknown) => {
-  const file = path.join(
-    os.tmpdir(),
-    `sessions-${Date.now()}-${Math.random().toString(16).slice(2)}.json`,
-  );
-  fs.writeFileSync(file, JSON.stringify(data, null, 2));
-  return file;
-};
-
 describe("sessionsCommand", () => {
   beforeEach(() => {
     vi.useFakeTimers();
@@ -126,18 +91,13 @@ describe("sessionsCommand", () => {
       },
     });
 
-    const { runtime, logs } = makeRuntime();
-    await sessionsCommand({ store, json: true }, runtime);
-
-    fs.rmSync(store);
-
-    const payload = JSON.parse(logs[0] ?? "{}") as {
+    const payload = await runSessionsJson<{
       sessions?: Array<{
         key: string;
         totalTokens: number | null;
         totalTokensFresh: boolean;
       }>;
-    };
+    }>(sessionsCommand, store);
     const main = payload.sessions?.find((row) => row.key === "main");
     const group = payload.sessions?.find((row) => row.key === "discord:group:demo");
     expect(main?.totalTokens).toBe(2000);
@@ -145,4 +105,47 @@ describe("sessionsCommand", () => {
     expect(group?.totalTokens).toBeNull();
     expect(group?.totalTokensFresh).toBe(false);
   });
+
+  it("applies --active filtering in JSON output", async () => {
+    const store = writeStore(
+      {
+        recent: {
+          sessionId: "recent",
+          updatedAt: Date.now() - 5 * 60_000,
+          model: "pi:opus",
+        },
+        stale: {
+          sessionId: "stale",
+          updatedAt: Date.now() - 45 * 60_000,
+          model: "pi:opus",
+        },
+      },
+      "sessions-active",
+    );
+
+    const payload = await runSessionsJson<{
+      sessions?: Array<{
+        key: string;
+      }>;
+    }>(sessionsCommand, store, { active: "10" });
+    expect(payload.sessions?.map((row) => row.key)).toEqual(["recent"]);
+  });
+
+  it("rejects invalid --active values", async () => {
+    const store = writeStore(
+      {
+        demo: {
+          sessionId: "demo",
+          updatedAt: Date.now() - 5 * 60_000,
+        },
+      },
+      "sessions-active-invalid",
+    );
+    const { runtime, errors } = makeRuntime();
+
+    await expect(sessionsCommand({ store, active: "0" }, runtime)).rejects.toThrow("exit 1");
+    expect(errors[0]).toContain("--active must be a positive integer");
+
+    fs.rmSync(store);
+  });
 });
diff --git a/src/commands/sessions.model-resolution.test.ts b/src/commands/sessions.model-resolution.test.ts
index 41bb3546881..4c0bac06759 100644
--- a/src/commands/sessions.model-resolution.test.ts
+++ b/src/commands/sessions.model-resolution.test.ts
@@ -1,50 +1,35 @@
-import fs from "node:fs";
-import os from "node:os";
-import path from "node:path";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { mockSessionsConfig, runSessionsJson, writeStore } from "./sessions.test-helpers.js";
 
-vi.mock("../config/config.js", async (importOriginal) => {
-  const actual = await importOriginal<typeof import("../config/config.js")>();
-  return {
-    ...actual,
-    loadConfig: () => ({
-      agents: {
-        defaults: {
-          model: { primary: "pi:opus" },
-          models: { "pi:opus": {} },
-          contextTokens: 32000,
-        },
-      },
-    }),
-  };
-});
+mockSessionsConfig();
 
 import { sessionsCommand } from "./sessions.js";
 
-const makeRuntime = () => {
-  const logs: string[] = [];
-  return {
-    runtime: {
-      log: (msg: unknown) => logs.push(String(msg)),
-      error: (msg: unknown) => {
-        throw new Error(String(msg));
-      },
-      exit: (code: number) => {
-        throw new Error(`exit ${code}`);
-      },
-    },
-    logs,
-  } as const;
+type SessionsJsonPayload = {
+  sessions?: Array<{
+    key: string;
+    model?: string | null;
+  }>;
 };
 
-const writeStore = (data: unknown) => {
-  const file = path.join(
-    os.tmpdir(),
-    `sessions-model-${Date.now()}-${Math.random().toString(16).slice(2)}.json`,
+async function resolveSubagentModel(
+  runtimeFields: Record<string, unknown>,
+  sessionId: string,
+): Promise<string | null | undefined> {
+  const store = writeStore(
+    {
+      "agent:research:subagent:demo": {
+        sessionId,
+        updatedAt: Date.now() - 2 * 60_000,
+        ...runtimeFields,
+      },
+    },
+    "sessions-model",
   );
-  fs.writeFileSync(file, JSON.stringify(data, null, 2));
-  return file;
-};
+
+  const payload = await runSessionsJson<SessionsJsonPayload>(sessionsCommand, store);
+  return payload.sessions?.find((row) => row.key === "agent:research:subagent:demo")?.model;
+}
 
 describe("sessionsCommand model resolution", () => {
   beforeEach(() => {
@@ -57,52 +42,22 @@ describe("sessionsCommand model resolution", () => {
   });
 
   it("prefers runtime model fields for subagent sessions in JSON output", async () => {
-    const store = writeStore({
-      "agent:research:subagent:demo": {
-        sessionId: "subagent-1",
-        updatedAt: Date.now() - 2 * 60_000,
+    const model = await resolveSubagentModel(
+      {
         modelProvider: "openai-codex",
         model: "gpt-5.3-codex",
         modelOverride: "pi:opus",
       },
-    });
-
-    const { runtime, logs } = makeRuntime();
-    await sessionsCommand({ store, json: true }, runtime);
-
-    fs.rmSync(store);
-
-    const payload = JSON.parse(logs[0] ?? "{}") as {
-      sessions?: Array<{
-        key: string;
-        model?: string | null;
-      }>;
-    };
-    const subagent = payload.sessions?.find((row) => row.key === "agent:research:subagent:demo");
-    expect(subagent?.model).toBe("gpt-5.3-codex");
+      "subagent-1",
+    );
+    expect(model).toBe("gpt-5.3-codex");
   });
 
   it("falls back to modelOverride when runtime model is missing", async () => {
-    const store = writeStore({
-      "agent:research:subagent:demo": {
-        sessionId: "subagent-2",
-        updatedAt: Date.now() - 2 * 60_000,
-        modelOverride: "openai-codex/gpt-5.3-codex",
-      },
-    });
-
-    const { runtime, logs } = makeRuntime();
-    await sessionsCommand({ store, json: true }, runtime);
-
-    fs.rmSync(store);
-
-    const payload = JSON.parse(logs[0] ?? "{}") as {
-      sessions?: Array<{
-        key: string;
-        model?: string | null;
-      }>;
-    };
-    const subagent = payload.sessions?.find((row) => row.key === "agent:research:subagent:demo");
-    expect(subagent?.model).toBe("gpt-5.3-codex");
+    const model = await resolveSubagentModel(
+      { modelOverride: "openai-codex/gpt-5.3-codex" },
+      "subagent-2",
+    );
+    expect(model).toBe("gpt-5.3-codex");
   });
 });
diff --git a/src/commands/sessions.test-helpers.ts b/src/commands/sessions.test-helpers.ts
new file mode 100644
index 00000000000..bd6b981ae08
--- /dev/null
+++ b/src/commands/sessions.test-helpers.ts
@@ -0,0 +1,84 @@
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { vi } from "vitest";
+import type { RuntimeEnv } from "../runtime.js";
+
+export function mockSessionsConfig() {
+  vi.mock("../config/config.js", async (importOriginal) => {
+    const actual = await importOriginal<typeof import("../config/config.js")>();
+    return {
+      ...actual,
+      loadConfig: () => ({
+        agents: {
+          defaults: {
+            model: { primary: "pi:opus" },
+            models: { "pi:opus": {} },
+            contextTokens: 32000,
+          },
+        },
+      }),
+    };
+  });
+}
+
+export function makeRuntime(params?: { throwOnError?: boolean }): {
+  runtime: RuntimeEnv;
+  logs: string[];
+  errors: string[];
+} {
+  const logs: string[] = [];
+  const errors: string[] = [];
+  const throwOnError = params?.throwOnError ?? false;
+  return {
+    runtime: {
+      log: (msg: unknown) => logs.push(String(msg)),
+      error: (msg: unknown) => {
+        errors.push(String(msg));
+        if (throwOnError) {
+          throw new Error(String(msg));
+        }
+      },
+      exit: (code: number) => {
+        throw new Error(`exit ${code}`);
+      },
+    },
+    logs,
+    errors,
+  };
+}
+
+export function writeStore(data: unknown, prefix = "sessions"): string {
+  const file = path.join(
+    os.tmpdir(),
+    `${prefix}-${Date.now()}-${Math.random().toString(16).slice(2)}.json`,
+  );
+  fs.writeFileSync(file, JSON.stringify(data, null, 2));
+  return file;
+}
+
+export async function runSessionsJson<T>(
+  run: (
+    opts: { json?: boolean; store?: string; active?: string },
+    runtime: RuntimeEnv,
+  ) => Promise<void>,
+  store: string,
+  options?: {
+    active?: string;
+  },
+): Promise<T> {
+  const { runtime, logs } = makeRuntime();
+  try {
+    await run(
+      {
+        store,
+        json: true,
+        active: options?.active,
+      },
+      runtime,
+    );
+  } finally {
+    fs.rmSync(store, { force: true });
+  }
+  return JSON.parse(logs[0] ?? "{}") as T;
+}