diff --git a/packages/cli/src/commands/api.ts b/packages/cli/src/commands/api.ts
index bc5ae7e..2a5f63f 100644
--- a/packages/cli/src/commands/api.ts
+++ b/packages/cli/src/commands/api.ts
@@ -1,6 +1,5 @@
 import { getClient } from "#utils/client.ts";
 import { defineCommand } from "citty";
-import consola from "consola";
 
 /**
  * Parses a `key=value` field string. Values are auto-converted:
@@ -145,13 +144,15 @@ export default defineCommand({
 			}
 
 			if (!args.silent) {
-				consola.log(JSON.stringify(allResults, null, 2));
+				const json = process.stdout.isTTY ? JSON.stringify(allResults, null, 2) : JSON.stringify(allResults);
+				process.stdout.write(`${json}\n`);
 			}
 		} else {
 			const result = await client<unknown>(endpoint, fetchOptions);
 
 			if (!args.silent) {
-				consola.log(JSON.stringify(result, null, 2));
+				const json = process.stdout.isTTY ? JSON.stringify(result, null, 2) : JSON.stringify(result);
+				process.stdout.write(`${json}\n`);
 			}
 		}
 	},
diff --git a/packages/cli/src/commands/space/activities.ts b/packages/cli/src/commands/space/activities.ts
index ea758b0..def672f 100644
--- a/packages/cli/src/commands/space/activities.ts
+++ b/packages/cli/src/commands/space/activities.ts
@@ -3,6 +3,7 @@ import type { SpacesGetActivitiesData } from "@repo/openapi-client";
 
 import { getClient } from "#utils/client.ts";
 import { formatDate, getActivityLabel, padEnd } from "#utils/format.ts";
+import { outputArgs, outputResult } from "#utils/output.ts";
 import { defineCommand } from "citty";
 import consola from "consola";
 
@@ -12,6 +13,7 @@ export default defineCommand({
 		description: "Show space activities",
 	},
 	args: {
+		...outputArgs,
 		limit: {
 			type: "string",
 			alias: "L",
@@ -38,19 +40,21 @@ export default defineCommand({
 			query,
 		});
 
-		if (activities.length === 0) {
-			consola.info("No activities found.");
-			return;
-		}
+		outputResult(activities, args, (data) => {
+			if (data.length === 0) {
+				consola.info("No activities found.");
+				return;
+			}
 
-		const header = `${padEnd("ID", 12)}${padEnd("TYPE", 24)}${padEnd("DATE", 12)}PROJECT`;
-		consola.log(header);
-		for (const activity of activities) {
-			const id = padEnd(`${activity.id}`, 12);
-			const type = padEnd(getActivityLabel(activity.type), 24);
-			const date = padEnd(formatDate(activity.created), 12);
-			const project = activity.project.projectKey;
-			consola.log(`${id}${type}${date}${project}`);
-		}
+			const header = `${padEnd("ID", 12)}${padEnd("TYPE", 24)}${padEnd("DATE", 12)}PROJECT`;
+			consola.log(header);
+			for (const activity of data) {
+				const id = padEnd(`${activity.id}`, 12);
+				const type = padEnd(getActivityLabel(activity.type), 24);
+				const date = padEnd(formatDate(activity.created), 12);
+				const project = activity.project.projectKey;
+				consola.log(`${id}${type}${date}${project}`);
+			}
+		});
 	},
 });
diff --git a/packages/integration-tests/src/commands/config/get-set.test.ts b/packages/integration-tests/src/commands/config/get-set.test.ts
index 2339b57..cfb59dc 100644
--- a/packages/integration-tests/src/commands/config/get-set.test.ts
+++ b/packages/integration-tests/src/commands/config/get-set.test.ts
@@ -3,24 +3,30 @@ import { describe, expect, it } from "vitest";
 import { expectSuccess } from "../../helpers/assertions.ts";
 import { runCli } from "../../helpers/cli.ts";
 
+// config get/set operates on global settings (not space-specific).
+// BACKLOG_SPACE must be unset to avoid space-specific config lookup/rejection.
+const envWithoutSpace = { BACKLOG_SPACE: "" };
+
 describe("config get/set", () => {
 	it("設定値を取得する", async () => {
-		const result = await runCli(["config", "get", "default_space"]);
+		const result = await runCli(["config", "get", "default_space"], { env: envWithoutSpace });
 		// This may or may not have a value, but should not error
 		expectSuccess(result);
 	});
 
 	it("設定値を設定して取得できる", async () => {
 		// Set a test value
-		const result = await runCli(["config", "set", "default_space", "test-space.backlog.com"]);
+		const result = await runCli(["config", "set", "default_space", "test-space.backlog.com"], {
+			env: envWithoutSpace,
+		});
 		expectSuccess(result);
 
 		// Read it back
-		const getResult = await runCli(["config", "get", "default_space"]);
+		const getResult = await runCli(["config", "get", "default_space"], { env: envWithoutSpace });
 		expectSuccess(getResult);
 		expect(getResult.stdout).toContain("test-space.backlog.com");
 
 		// Reset - set to empty to clean up
-		await runCli(["config", "set", "default_space", ""]);
+		await runCli(["config", "set", "default_space", ""], { env: envWithoutSpace });
 	});
 });
diff --git a/packages/integration-tests/src/commands/project/activities.test.ts b/packages/integration-tests/src/commands/project/activities.test.ts
index e66a08f..65d97db 100644
--- a/packages/integration-tests/src/commands/project/activities.test.ts
+++ b/packages/integration-tests/src/commands/project/activities.test.ts
@@ -8,12 +8,12 @@ describe("project activities", () => {
 	const { project } = getEnv();
 
 	it("プロジェクトの活動を表示する", async () => {
-		const result = await runCliWithRetry(["project", "activities", "-p", project]);
+		const result = await runCliWithRetry(["project", "activities", project]);
 		expectSuccess(result);
 	});
 
 	it("--json でプロジェクト活動を JSON 配列で出力する", async () => {
-		const result = await runCliWithRetry(["project", "activities", "-p", project, "--json"]);
+		const result = await runCliWithRetry(["project", "activities", project, "--json"]);
 		expectJsonArray(result);
 	});
 });
diff --git a/packages/integration-tests/src/commands/project/users.test.ts b/packages/integration-tests/src/commands/project/users.test.ts
index 4dd9904..612e351 100644
--- a/packages/integration-tests/src/commands/project/users.test.ts
+++ b/packages/integration-tests/src/commands/project/users.test.ts
@@ -8,12 +8,12 @@ describe("project users", () => {
 	const { project } = getEnv();
 
 	it("プロジェクトメンバーを表示する", async () => {
-		const result = await runCliWithRetry(["project", "users", "-p", project]);
+		const result = await runCliWithRetry(["project", "users", project]);
 		expectSuccess(result);
 	});
 
 	it("--json でプロジェクトメンバーを JSON 配列で出力する", async () => {
-		const result = await runCliWithRetry(["project", "users", "-p", project, "--json"]);
+		const result = await runCliWithRetry(["project", "users", project, "--json"]);
 		expectJsonArray(result);
 	});
 });
diff --git a/packages/integration-tests/src/commands/repo/list.test.ts b/packages/integration-tests/src/commands/repo/list.test.ts
index 54a93fb..17d5092 100644
--- a/packages/integration-tests/src/commands/repo/list.test.ts
+++ b/packages/integration-tests/src/commands/repo/list.test.ts
@@ -8,12 +8,12 @@ describe("repo list", () => {
 	const { project } = getEnv();
 
 	it("リポジトリ一覧を表示する", async () => {
-		const result = await runCliWithRetry(["repo", "list", "-p", project]);
+		const result = await runCliWithRetry(["repo", "list", project]);
 		expectSuccess(result);
 	});
 
 	it("--json でリポジトリ一覧を JSON 配列で出力する", async () => {
-		const result = await runCliWithRetry(["repo", "list", "-p", project, "--json"]);
+		const result = await runCliWithRetry(["repo", "list", project, "--json"]);
 		expectJsonArray(result);
 	});
 });
diff --git a/packages/integration-tests/vitest.config.ts b/packages/integration-tests/vitest.config.ts
index 8d4dd85..e9b118a 100644
--- a/packages/integration-tests/vitest.config.ts
+++ b/packages/integration-tests/vitest.config.ts
@@ -11,10 +11,6 @@ export default defineConfig({
 			concurrent: false,
 		},
 		pool: "forks",
-		poolOptions: {
-			forks: {
-				singleFork: true,
-			},
-		},
+		fileParallelism: false,
 	},
 });