From 11b07c8b9552a121825d9b2e4a24afd54a3a1e53 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 12 Mar 2026 20:50:34 +0000
Subject: [PATCH 1/6] Initial plan


From a295d7fbb31a1f2137a6bd34eda4783440b02125 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 12 Mar 2026 21:01:03 +0000
Subject: [PATCH 2/6] Add RUSH_QUIET_MODE environment variable

Co-authored-by: dmichon-msft <26827560+dmichon-msft@users.noreply.github.com>
---
 .../add-rush-quiet-mode_2026-03-12-20-51.json | 10 ++++++
 .../add-rush-quiet-mode_2026-03-12-20-51.json | 10 ++++++
 .../src/api/EnvironmentConfiguration.ts       | 36 ++++++++++++++++++-
 .../rush-lib/src/cli/RushCommandLineParser.ts |  7 ++++
 .../rush-lib/src/cli/RushXCommandLine.ts      |  6 ++++
 .../rush-lib/src/scripts/install-run-rush.ts  |  9 +++++
 6 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json
 create mode 100644 common/changes/@microsoft/rush/add-rush-quiet-mode_2026-03-12-20-51.json

diff --git a/common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json b/common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json
new file mode 100644
index 00000000000..4c9ee61d615
--- /dev/null
+++ b/common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush-lib",
+      "comment": "Add RUSH_QUIET_MODE environment variable that, when set to `1` or `true`, is equivalent to passing `--quiet` for `rush`, `rushx`, and `install-run-rush.ts`",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@microsoft/rush-lib"
+}
diff --git a/common/changes/@microsoft/rush/add-rush-quiet-mode_2026-03-12-20-51.json b/common/changes/@microsoft/rush/add-rush-quiet-mode_2026-03-12-20-51.json
new file mode 100644
index 00000000000..dc6f3446651
--- /dev/null
+++ b/common/changes/@microsoft/rush/add-rush-quiet-mode_2026-03-12-20-51.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush",
+      "comment": "Add RUSH_QUIET_MODE environment variable that, when set to `1` or `true`, is equivalent to passing `--quiet` for `rush`, `rushx`, and `install-run-rush.ts`",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@microsoft/rush"
+}
diff --git a/libraries/rush-lib/src/api/EnvironmentConfiguration.ts b/libraries/rush-lib/src/api/EnvironmentConfiguration.ts
index f7a00179197..e60a37a6f3e 100644
--- a/libraries/rush-lib/src/api/EnvironmentConfiguration.ts
+++ b/libraries/rush-lib/src/api/EnvironmentConfiguration.ts
@@ -245,7 +245,14 @@ export const EnvironmentVariableNames = {
    * Other lifecycle scripts should not make assumptions about Rush's command line syntax
    * if Rush did not explicitly pass along command-line parameters to their process.
    */
-  RUSH_INVOKED_ARGS: 'RUSH_INVOKED_ARGS'
+  RUSH_INVOKED_ARGS: 'RUSH_INVOKED_ARGS',
+
+  /**
+   * When set to `1` or `true`, this environment variable is equivalent to passing the `--quiet` flag
+   * to `rush`, `rushx`, and `install-run-rush.ts`. It suppresses informational startup messages
+   * while preserving error output.
+   */
+  RUSH_QUIET_MODE: 'RUSH_QUIET_MODE'
 } as const;
 
 /**
@@ -293,6 +300,8 @@ export class EnvironmentConfiguration {
 
   private static _tarBinaryPath: string | undefined;
 
+  private static _quietMode: boolean = false;
+
   /**
    * If true, the environment configuration has been validated and initialized.
    */
@@ -456,6 +465,15 @@ export class EnvironmentConfiguration {
     return EnvironmentConfiguration._tarBinaryPath;
   }
 
+  /**
+   * If `true`, Rush will suppress informational startup messages, equivalent to passing `--quiet`.
+   * See {@link EnvironmentVariableNames.RUSH_QUIET_MODE}
+   */
+  public static get quietMode(): boolean {
+    EnvironmentConfiguration._ensureValidated();
+    return EnvironmentConfiguration._quietMode;
+  }
+
   /**
    * The front-end RushVersionSelector relies on `RUSH_GLOBAL_FOLDER`, so its value must be read before
    * `EnvironmentConfiguration` is initialized (and actually before the correct version of `EnvironmentConfiguration`
@@ -606,6 +624,20 @@ export class EnvironmentConfiguration {
             break;
           }
 
+          case EnvironmentVariableNames.RUSH_QUIET_MODE: {
+            // Accept both "true"/"false" string values and the standard "1"/"0" values
+            if (value === 'true' || value === 'false') {
+              EnvironmentConfiguration._quietMode = value === 'true';
+            } else {
+              EnvironmentConfiguration._quietMode =
+                EnvironmentConfiguration.parseBooleanEnvironmentVariable(
+                  EnvironmentVariableNames.RUSH_QUIET_MODE,
+                  value
+                ) ?? false;
+            }
+            break;
+          }
+
           case EnvironmentVariableNames.RUSH_PARALLELISM:
           case EnvironmentVariableNames.RUSH_PREVIEW_VERSION:
           case EnvironmentVariableNames.RUSH_VARIANT:
@@ -662,6 +694,8 @@ export class EnvironmentConfiguration {
   public static reset(): void {
     EnvironmentConfiguration._rushTempFolderOverride = undefined;
 
+    EnvironmentConfiguration._quietMode = false;
+
     EnvironmentConfiguration._hasBeenValidated = false;
   }
 
diff --git a/libraries/rush-lib/src/cli/RushCommandLineParser.ts b/libraries/rush-lib/src/cli/RushCommandLineParser.ts
index 7828eb1e90d..cce1a59d91c 100644
--- a/libraries/rush-lib/src/cli/RushCommandLineParser.ts
+++ b/libraries/rush-lib/src/cli/RushCommandLineParser.ts
@@ -63,6 +63,7 @@ import { InitSubspaceAction } from './actions/InitSubspaceAction';
 import { RushAlerts } from '../utilities/RushAlerts';
 import { initializeDotEnv } from '../logic/dotenv';
 import { measureAsyncFn } from '../utilities/performance';
+import { EnvironmentVariableNames } from '../api/EnvironmentConfiguration';
 
 /**
  * Options for `RushCommandLineParser`.
@@ -220,6 +221,12 @@ export class RushCommandLineParser extends CommandLineParser {
       }
     }
 
+    const quietModeValue: string | undefined =
+      process.env[EnvironmentVariableNames.RUSH_QUIET_MODE];
+    if (quietModeValue === '1' || quietModeValue === 'true') {
+      return true;
+    }
+
     return false;
   }
 
diff --git a/libraries/rush-lib/src/cli/RushXCommandLine.ts b/libraries/rush-lib/src/cli/RushXCommandLine.ts
index 03648e831b8..20a856b1f7b 100644
--- a/libraries/rush-lib/src/cli/RushXCommandLine.ts
+++ b/libraries/rush-lib/src/cli/RushXCommandLine.ts
@@ -295,6 +295,12 @@ export class RushXCommandLine {
       }
     }
 
+    const quietModeValue: string | undefined =
+      process.env[EnvironmentVariableNames.RUSH_QUIET_MODE];
+    if (quietModeValue === '1' || quietModeValue === 'true') {
+      quiet = true;
+    }
+
     if (!commandName) {
       help = true;
     }
diff --git a/libraries/rush-lib/src/scripts/install-run-rush.ts b/libraries/rush-lib/src/scripts/install-run-rush.ts
index bfb986d46e4..5b689b9bf9f 100644
--- a/libraries/rush-lib/src/scripts/install-run-rush.ts
+++ b/libraries/rush-lib/src/scripts/install-run-rush.ts
@@ -16,6 +16,7 @@ import type { ILogger } from '../utilities/npmrcUtilities';
 
 const PACKAGE_NAME: string = '@microsoft/rush';
 const RUSH_PREVIEW_VERSION: string = 'RUSH_PREVIEW_VERSION';
+const RUSH_QUIET_MODE: string = 'RUSH_QUIET_MODE';
 const INSTALL_RUN_RUSH_LOCKFILE_PATH_VARIABLE: 'INSTALL_RUN_RUSH_LOCKFILE_PATH' =
   'INSTALL_RUN_RUSH_LOCKFILE_PATH';
 
@@ -74,6 +75,14 @@ function _run(): void {
   let commandFound: boolean = false;
   let logger: ILogger = { info: console.log, error: console.error };
 
+  const quietModeEnvValue: string | undefined = process.env[RUSH_QUIET_MODE];
+  if (quietModeEnvValue === '1' || quietModeEnvValue === 'true') {
+    logger = {
+      info: () => {},
+      error: console.error
+    };
+  }
+
   for (const arg of packageBinArgs) {
     if (arg === '-q' || arg === '--quiet') {
       // The -q/--quiet flag is supported by both `rush` and `rushx`, and will suppress

From 6ae0d6a2063eeeb8c2ee566b8c009bf7bfa26bc1 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 12 Mar 2026 21:25:16 +0000
Subject: [PATCH 3/6] Remove erroneous @microsoft/rush-lib change file

Co-authored-by: dmichon-msft <26827560+dmichon-msft@users.noreply.github.com>
---
 .../rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json | 10 ----------
 1 file changed, 10 deletions(-)
 delete mode 100644 common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json

diff --git a/common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json b/common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json
deleted file mode 100644
index 4c9ee61d615..00000000000
--- a/common/changes/@microsoft/rush-lib/add-rush-quiet-mode_2026-03-12-20-51.json
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "changes": [
-    {
-      "packageName": "@microsoft/rush-lib",
-      "comment": "Add RUSH_QUIET_MODE environment variable that, when set to `1` or `true`, is equivalent to passing `--quiet` for `rush`, `rushx`, and `install-run-rush.ts`",
-      "type": "minor"
-    }
-  ],
-  "packageName": "@microsoft/rush-lib"
-}

From b55606c44244bb91070705093f27ea22ddfa8e9a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 12 Mar 2026 21:32:14 +0000
Subject: [PATCH 4/6] Deduplicate quiet mode handling in install-run-rush; fix
 reset() method

Co-authored-by: dmichon-msft <26827560+dmichon-msft@users.noreply.github.com>
---
 .../src/api/EnvironmentConfiguration.ts         |  4 ++--
 .../rush-lib/src/scripts/install-run-rush.ts    | 17 ++++++-----------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/libraries/rush-lib/src/api/EnvironmentConfiguration.ts b/libraries/rush-lib/src/api/EnvironmentConfiguration.ts
index e60a37a6f3e..de8c8d2d2ff 100644
--- a/libraries/rush-lib/src/api/EnvironmentConfiguration.ts
+++ b/libraries/rush-lib/src/api/EnvironmentConfiguration.ts
@@ -693,9 +693,9 @@ export class EnvironmentConfiguration {
    */
   public static reset(): void {
     EnvironmentConfiguration._rushTempFolderOverride = undefined;
-
     EnvironmentConfiguration._quietMode = false;
-
+    EnvironmentConfiguration._gitBinaryPath = undefined;
+    EnvironmentConfiguration._tarBinaryPath = undefined;
     EnvironmentConfiguration._hasBeenValidated = false;
   }
 
diff --git a/libraries/rush-lib/src/scripts/install-run-rush.ts b/libraries/rush-lib/src/scripts/install-run-rush.ts
index 5b689b9bf9f..6fa7e8b21b5 100644
--- a/libraries/rush-lib/src/scripts/install-run-rush.ts
+++ b/libraries/rush-lib/src/scripts/install-run-rush.ts
@@ -73,15 +73,9 @@ function _run(): void {
   }
 
   let commandFound: boolean = false;
-  let logger: ILogger = { info: console.log, error: console.error };
 
   const quietModeEnvValue: string | undefined = process.env[RUSH_QUIET_MODE];
-  if (quietModeEnvValue === '1' || quietModeEnvValue === 'true') {
-    logger = {
-      info: () => {},
-      error: console.error
-    };
-  }
+  let quiet: boolean = quietModeEnvValue === '1' || quietModeEnvValue === 'true';
 
   for (const arg of packageBinArgs) {
     if (arg === '-q' || arg === '--quiet') {
@@ -91,10 +85,7 @@ function _run(): void {
       // To maintain the same user experience, the install-run* scripts pass along this
       // flag but also use it to suppress any diagnostic information normally printed
       // to stdout.
-      logger = {
-        info: () => {},
-        error: console.error
-      };
+      quiet = true;
     } else if (!arg.startsWith('-') || arg === '-h' || arg === '--help') {
       // We either found something that looks like a command (i.e. - doesn't start with a "-"),
       // or we found the -h/--help flag, which can be run without a command
@@ -114,6 +105,10 @@ function _run(): void {
     process.exit(1);
   }
 
+  const logger: ILogger = quiet
+    ? { info: () => {}, error: console.error }
+    : { info: console.log, error: console.error };
+
   runWithErrorAndStatusCode(logger, () => {
     const version: string = _getRushVersion(logger);
     logger.info(`The ${RUSH_JSON_FILENAME} configuration requests Rush version ${version}`);

From 3910a1c0fe1f3ab48f29f6afdc4a58c7caaff581 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 13 Mar 2026 20:35:57 +0000
Subject: [PATCH 5/6] Update rush-lib.api.md with quietMode and RUSH_QUIET_MODE
 API entries

Co-authored-by: dmichon-msft <26827560+dmichon-msft@users.noreply.github.com>
---
 common/reviews/api/rush-lib.api.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/common/reviews/api/rush-lib.api.md b/common/reviews/api/rush-lib.api.md
index e7004ddbbc2..b4822543b94 100644
--- a/common/reviews/api/rush-lib.api.md
+++ b/common/reviews/api/rush-lib.api.md
@@ -239,6 +239,7 @@ export class EnvironmentConfiguration {
     static parseBooleanEnvironmentVariable(name: string, value: string | undefined): boolean | undefined;
     static get pnpmStorePathOverride(): string | undefined;
     static get pnpmVerifyStoreIntegrity(): boolean | undefined;
+    static get quietMode(): boolean;
     static reset(): void;
     static get rushGlobalFolderOverride(): string | undefined;
     static get rushTempFolderOverride(): string | undefined;
@@ -269,6 +270,7 @@ export const EnvironmentVariableNames: {
     readonly RUSH_COBUILD_LEAF_PROJECT_LOG_ONLY_ALLOWED: "RUSH_COBUILD_LEAF_PROJECT_LOG_ONLY_ALLOWED";
     readonly RUSH_GIT_BINARY_PATH: "RUSH_GIT_BINARY_PATH";
     readonly RUSH_TAR_BINARY_PATH: "RUSH_TAR_BINARY_PATH";
+    readonly RUSH_QUIET_MODE: "RUSH_QUIET_MODE";
     readonly _RUSH_RECURSIVE_RUSHX_CALL: "_RUSH_RECURSIVE_RUSHX_CALL";
     readonly _RUSH_LIB_PATH: "_RUSH_LIB_PATH";
     readonly RUSH_INVOKED_FOLDER: "RUSH_INVOKED_FOLDER";

From 3e8bca27f5d9bb8d895e0b4c54a5be7b100a825a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 13 Mar 2026 21:47:20 +0000
Subject: [PATCH 6/6] Fix RUSH_QUIET_MODE position in rush-lib.api.md to match
 source declaration order

Co-authored-by: dmichon-msft <26827560+dmichon-msft@users.noreply.github.com>
---
 common/reviews/api/rush-lib.api.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/reviews/api/rush-lib.api.md b/common/reviews/api/rush-lib.api.md
index b4822543b94..14063d1543e 100644
--- a/common/reviews/api/rush-lib.api.md
+++ b/common/reviews/api/rush-lib.api.md
@@ -270,11 +270,11 @@ export const EnvironmentVariableNames: {
     readonly RUSH_COBUILD_LEAF_PROJECT_LOG_ONLY_ALLOWED: "RUSH_COBUILD_LEAF_PROJECT_LOG_ONLY_ALLOWED";
     readonly RUSH_GIT_BINARY_PATH: "RUSH_GIT_BINARY_PATH";
     readonly RUSH_TAR_BINARY_PATH: "RUSH_TAR_BINARY_PATH";
-    readonly RUSH_QUIET_MODE: "RUSH_QUIET_MODE";
     readonly _RUSH_RECURSIVE_RUSHX_CALL: "_RUSH_RECURSIVE_RUSHX_CALL";
     readonly _RUSH_LIB_PATH: "_RUSH_LIB_PATH";
     readonly RUSH_INVOKED_FOLDER: "RUSH_INVOKED_FOLDER";
     readonly RUSH_INVOKED_ARGS: "RUSH_INVOKED_ARGS";
+    readonly RUSH_QUIET_MODE: "RUSH_QUIET_MODE";
 };
 
 // @beta