@@ -27,6 +27,7 @@ export type DependencyType = 'dev' | 'prod' | 'peer';
  */
 export declare const packageManager: readonly ["yarn", "npm", "pnpm", "bun", "homebrew", "unknown"];
 export type PackageManager = (typeof packageManager)[number];
+export type ProjectPackageManager = Extract<PackageManager, 'yarn' | 'npm' | 'pnpm' | 'bun'>;
 /**
  * Returns an abort error that's thrown when the package manager can't be determined.
  * @returns An abort error.
@@ -68,6 +69,58 @@ export declare function packageManagerFromUserAgent(env?: NodeJS.ProcessEnv): Pa
  * @returns The dependency manager
  */
 export declare function getPackageManager(fromDirectory: string): Promise<PackageManager>;
+/**
+ * Resolves the package manager for a directory already known to be the project root.
+ *
+ * Use this when the caller already knows the root directory and wants to inspect that root
+ * directly rather than walking upward from a child directory.
+ *
+ * @param rootDirectory - The known project root directory.
+ * @returns The package manager detected from root markers, defaulting to npm <command>
+
+Usage:
+
+npm install        install all the dependencies in your project
+npm install <foo>  add the <foo> dependency to your project
+npm test           run this project's tests
+npm run <foo>      run the script named <foo>
+npm <command> -h   quick help on <command>
+npm -l             display usage info for all commands
+npm help <term>    search for help on <term>
+npm help npm       more involved overview
+
+All commands:
+
+    access, adduser, audit, bugs, cache, ci, completion,
+    config, dedupe, deprecate, diff, dist-tag, docs, doctor,
+    edit, exec, explain, explore, find-dupes, fund, get, help,
+    help-search, init, install, install-ci-test, install-test,
+    link, ll, login, logout, ls, org, outdated, owner, pack,
+    ping, pkg, prefix, profile, prune, publish, query, rebuild,
+    repo, restart, root, run-script, sbom, search, set,
+    shrinkwrap, star, stars, start, stop, team, test, token,
+    undeprecate, uninstall, unpublish, unstar, update, version,
+    view, whoami
+
+Specify configs in the ini-formatted file:
+    /home/runner/work/_temp/.npmrc
+or on the command line via: npm <command> --key=value
+
+More configuration info: npm help config
+Configuration fields: npm help 7 config
+
+npm@11.3.0 /opt/hostedtoolcache/node/24.1.0/x64/lib/node_modules/npm when no marker exists.
+ * @throws PackageJsonNotFoundError if the provided directory does not contain a package.json.
+ */
+export declare function getPackageManagerForProjectRoot(rootDirectory: string): Promise<ProjectPackageManager>;
+/**
+ * Builds the command and argv needed to execute a local binary using the package manager
+ * detected from the provided directory or its ancestors.
+ */
+export declare function packageManagerBinaryCommandForDirectory(fromDirectory: string, binary: string, ...binaryArgs: string[]): Promise<{
+    command: string;
+    args: string[];
+}>;
 interface InstallNPMDependenciesRecursivelyOptions {
     /**
      * The dependency manager to use to install the dependencies.