From b5dace71b6bde367c63a1de62da0a576faede383 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Sat, 30 Aug 2025 00:11:09 +0000
Subject: [PATCH 01/20] chore: add support for librarian release init

---
 .generator/cli.py | 282 +++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 265 insertions(+), 17 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 4b7892456237..ee43fa0dd09d 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -14,6 +14,7 @@
 
 import argparse
 import glob
+import itertools
 import json
 import logging
 import os
@@ -21,9 +22,12 @@
 import shutil
 import subprocess
 import sys
+from datetime import datetime
 from pathlib import Path
 from typing import Dict, List
 
+import yaml
+
 try:
     import synthtool
     from synthtool.languages import python_mono_repo
@@ -36,13 +40,16 @@
 
 logger = logging.getLogger()
 
-LIBRARIAN_DIR = "librarian"
+BUILD_REQUEST_FILE = "build-request.json"
 GENERATE_REQUEST_FILE = "generate-request.json"
+RELEASE_INIT_REQUEST_FILE = "release-init-request.json"
+STATE_YAML_FILE = "state.yaml"
+
 INPUT_DIR = "input"
-BUILD_REQUEST_FILE = "build-request.json"
-SOURCE_DIR = "source"
+LIBRARIAN_DIR = "librarian"
 OUTPUT_DIR = "output"
 REPO_DIR = "repo"
+SOURCE_DIR = "source"
 
 
 def _read_json_file(path: str) -> Dict:
@@ -433,23 +440,256 @@ def handle_build(librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR):
     logger.info("'build' command executed.")
 
 
-if __name__ == "__main__":  # pragma: NO COVER
+def _read_and_process_file(input_path: str, output_path: str, process_func) -> None:
+    """Helper function to read, process, and write a file.
+
+    Args:
+        input_path (str): The path to the file to read.
+        output_path (str): The path to the file to write.
+        process_func (callable): A function that takes the file content as a string
+                                  and returns the modified string.
+    """
+    os.makedirs(Path(output_path).parent, exist_ok=True)
+    shutil.copy(input_path, output_path)
+
+    with open(output_path, "r", encoding="utf-8") as f:
+        content = f.read()
+
+    updated_content = process_func(content)
+
+    with open(output_path, "w", encoding="utf-8") as f:
+        f.write(updated_content)
+
+
+def _get_libraries_to_prepare_for_release(library_entries: Dict) -> List[dict]:
+    """Note the request data may have multiple libraries in it. Locate all
+    libraries which should be prepared for release. This can be done by
+    checking whether the `release_triggered` field is `true`.
+
+    Args:
+        library_entries(Dict): Dictionary containing all of the libraries
+        present in the repository.
+
+    Returns:
+        List[dict]: List of all libraries which should be prepared for release,
+        along with the corresponding information for the release.
+    """
+    return [
+        library
+        for library in library_entries["libraries"]
+        if library.get("release_triggered")
+    ]
+
+
+def handle_release_init(
+    librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR, output: str = OUTPUT_DIR
+):
+    """The main coordinator for the release process.
+
+    This function prepares for the release of client libraries by reading a
+    `librarian/release-init-request.json` file. The primary responsibility is
+    to update all required files with the new version and commit information
+    for libraries that have the `release_triggered` field set to `true`.
+
+    See https://github.com/googleapis/librarian/blob/main/doc/container-contract.md#generate-container-command
+
+    Args:
+        librarian(str): Path to the directory in the container which contains
+            the `release-init-request.json` file
+        repo(str): This directory will contain all directories that make up a
+            library, the .librarian folder, and any global file declared in
+            the config.yaml.
+        output(str): Path to the directory in the container where modified
+            code should be placed.
+    """
+
+    try:
+        # Read a release-init-request.json file
+        request_data = _read_json_file(f"{librarian}/{RELEASE_INIT_REQUEST_FILE}")
+        libraries_to_prep_for_release = _get_libraries_to_prepare_for_release(
+            request_data
+        )
+
+        # Update the main changelog file
+        source_path = f"{repo}/CHANGELOG.md"
+        output_path = f"{output}/CHANGELOG.md"
+        _update_global_changelog(
+            source_path, output_path, libraries_to_prep_for_release
+        )
+
+        # Process each library to be released
+        for library_release_data in libraries_to_prep_for_release:
+            version = library_release_data["version"]
+            library_changes = library_release_data["changes"]
+            package_name = library_release_data["id"]
+            path_to_library = f"packages/{package_name}"
+
+            # Get previous version from state.yaml
+            previous_version = _get_previous_version(repo, package_name)
+
+            _update_version_for_library(repo, output, path_to_library, version)
+            if previous_version != version:
+                _update_changelog_for_library(
+                    repo,
+                    output,
+                    library_changes,
+                    version,
+                    previous_version,
+                    package_name,
+                )
+
+    except Exception as e:
+        raise ValueError(f"Release init failed: {e}") from e
+
+
+def _get_previous_version(repo: str, package_name: str) -> str:
+    """Gets the previous version of the library from state.yaml."""
+    state_yaml_path = f"{repo}/.librarian/{STATE_YAML_FILE}"
+    if not os.path.exists(state_yaml_path):
+        raise FileNotFoundError(f"State file not found at {state_yaml_path}")
+
+    with open(state_yaml_path, "r") as state_yaml_file:
+        state_yaml = yaml.safe_load(state_yaml_file)
+        for library in state_yaml.get("libraries", []):
+            if library.get("id") == package_name:
+                return library.get("version")
+
+    raise ValueError(
+        f"Could not determine previous version for {package_name} from state.yaml"
+    )
+
+
+def _update_global_changelog(source_path: str, output_path: str, libraries: List[dict]):
+    """Updates the main CHANGELOG.md with new versions."""
+
+    def process_content(content):
+        new_content = content
+        for lib in libraries:
+            package_name = lib["id"]
+            version = lib["version"]
+            pattern = re.compile(f"(\\[{re.escape(package_name)})(==)([\\d\\.]+)(\\])")
+            replacement = f"\\g<1>=={version}\\g<4>"
+            new_content = pattern.sub(replacement, new_content)
+        return new_content
+
+    _read_and_process_file(source_path, output_path, process_content)
+
+
+def _update_changelog_for_library(
+    repo: str,
+    output: str,
+    library_changes: List[Dict],
+    version: str,
+    previous_version: str,
+    package_name: str,
+):
+    """Prepends a new release entry with multiple, grouped changes to a changelog."""
+
+    def process_content(content):
+        repo_url = "https://github.com/googleapis/google-cloud-python"
+        current_date = datetime.now().strftime("%Y-%m-%d")
+
+        # Create the main version header
+        version_header = (
+            f"## [{version}]({repo_url}/compare/{package_name}-v{previous_version}"
+            f"...{package_name}-v{version}) ({current_date})"
+        )
+        entry_parts = [version_header]
+
+        # Group changes by type (e.g., feat, fix, docs)
+        library_changes.sort(key=lambda x: x["type"])
+        grouped_changes = itertools.groupby(library_changes, key=lambda x: x["type"])
+
+        for change_type, changes in grouped_changes:
+            # We only care about feat, fix, docs
+            if change_type.replace("!", "") in ["feat", "fix", "docs"]:
+                entry_parts.append(
+                    f"\n\n### {change_type.capitalize().replace('!', '')}\n"
+                )
+                for change in changes:
+                    commit_link = f"([{change['source_commit_hash']}]({repo_url}/commit/{change['source_commit_hash']}))"
+                    entry_parts.append(f"* {change['subject']} {commit_link}")
+
+        new_entry_text = "\n".join(entry_parts)
+        anchor_pattern = re.compile(
+            r"(\[1\]: https://pypi\.org/project/google-cloud-language/#history)",
+            re.MULTILINE,
+        )
+        replacement_text = f"\\g<1>\n\n{new_entry_text}"
+        updated_content, num_subs = anchor_pattern.subn(
+            replacement_text, content, count=1
+        )
+
+        if num_subs == 0:
+            raise ValueError("Changelog anchor '[1]: ...#history' not found.")
+
+        return updated_content
+
+    source_path = f"{repo}/packages/{package_name}/CHANGELOG.md"
+    output_path = f"{output}/packages/{package_name}/CHANGELOG.md"
+    _read_and_process_file(source_path, output_path, process_content)
+
+
+def _update_version_for_library(
+    repo: str, output: str, path_to_library: str, version: str
+):
+    """Updates the version string in various files for a library."""
+
+    # Find and update gapic_version.py files
+    gapic_version_files = Path(f"{repo}/{path_to_library}").rglob("**/gapic_version.py")
+    for version_file in gapic_version_files:
+
+        def process_version_file(content):
+            pattern = r"(__version__\s*=\s*[\"'])([^\"']+)([\"'].*)"
+            replacement_string = f"\\g<1>{version}\\g<3>"
+            new_content, num_replacements = re.subn(
+                pattern, replacement_string, content
+            )
+            if num_replacements == 0:
+                raise Exception(
+                    f"Could not find version string in {version_file}. File was not modified."
+                )
+            return new_content
+
+        output_path = f"{output}/{version_file.relative_to(repo)}"
+        _read_and_process_file(str(version_file), output_path, process_version_file)
+
+    # Find and update snippet_metadata.json files
+    snippet_metadata_files = Path(f"{repo}/{path_to_library}").rglob(
+        "samples/**/*.json"
+    )
+    for metadata_file in snippet_metadata_files:
+        output_path = f"{output}/{metadata_file.relative_to(repo)}"
+        os.makedirs(Path(output_path).parent, exist_ok=True)
+        shutil.copy(metadata_file, output_path)
+
+        metadata_contents = _read_json_file(metadata_file)
+        metadata_contents["clientLibrary"]["version"] = version
+
+        with open(output_path, "w") as f:
+            json.dump(metadata_contents, f, indent=2)
+            f.write("\n")
+
+
+def main():
     parser = argparse.ArgumentParser(description="A simple CLI tool.")
     subparsers = parser.add_subparsers(
         dest="command", required=True, help="Available commands"
     )
 
-    # Define commands
+    # Define commands and their corresponding handler functions
     handler_map = {
         "configure": handle_configure,
         "generate": handle_generate,
         "build": handle_build,
+        "release-init": handle_release_init,
     }
 
     for command_name, help_text in [
         ("configure", "Onboard a new library or an api path to Librarian workflow."),
         ("generate", "generate a python client for an API."),
         ("build", "Run unit tests via nox for the generated library."),
+        ("release-init", "Prepare to release a specific library"),
     ]:
         parser_cmd = subparsers.add_parser(command_name, help=help_text)
         parser_cmd.set_defaults(func=handler_map[command_name])
@@ -483,21 +723,29 @@ def handle_build(librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR):
             help="Path to the directory in the container which contains google-cloud-python repository",
             default=SOURCE_DIR,
         )
+
     if len(sys.argv) == 1:
         parser.print_help(sys.stderr)
         sys.exit(1)
 
     args = parser.parse_args()
 
-    # Pass specific arguments to the handler functions for generate/build
-    if args.command == "generate":
-        args.func(
-            librarian=args.librarian,
-            source=args.source,
-            output=args.output,
-            input=args.input,
-        )
-    elif args.command == "build":
-        args.func(librarian=args.librarian, repo=args.repo)
-    else:
-        args.func()
+    # Pass arguments to the selected handler function using a dynamic approach
+    handler_args = {
+        k: v for k, v in vars(args).items() if k != "command" and k != "func"
+    }
+    # Filter out arguments not expected by the function
+    import inspect
+
+    handler_func = args.func
+    arg_spec = inspect.getfullargspec(handler_func)
+
+    valid_handler_args = {
+        k: v for k, v in handler_args.items() if k in arg_spec.args or arg_spec.varkw
+    }
+
+    handler_func(**valid_handler_args)
+
+
+if __name__ == "__main__":  # pragma: NO COVER
+    main()

From 4dabaf62ddec2fd39b26e4e5b17e90a5e88e6229 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 10:32:37 +0000
Subject: [PATCH 02/20] split code changes

---
 .generator/cli.py | 199 ++++++----------------------------------------
 1 file changed, 24 insertions(+), 175 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index ee43fa0dd09d..7d0b235e3ace 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -14,7 +14,6 @@
 
 import argparse
 import glob
-import itertools
 import json
 import logging
 import os
@@ -22,12 +21,9 @@
 import shutil
 import subprocess
 import sys
-from datetime import datetime
 from pathlib import Path
 from typing import Dict, List
 
-import yaml
-
 try:
     import synthtool
     from synthtool.languages import python_mono_repo
@@ -43,7 +39,6 @@
 BUILD_REQUEST_FILE = "build-request.json"
 GENERATE_REQUEST_FILE = "generate-request.json"
 RELEASE_INIT_REQUEST_FILE = "release-init-request.json"
-STATE_YAML_FILE = "state.yaml"
 
 INPUT_DIR = "input"
 LIBRARIAN_DIR = "librarian"
@@ -378,7 +373,6 @@ def handle_generate(
     except Exception as e:
         raise ValueError("Generation failed.") from e
 
-    # TODO(https://github.com/googleapis/librarian/issues/448): Implement generate command and update docstring.
     logger.info("'generate' command executed.")
 
 
@@ -510,166 +504,22 @@ def handle_release_init(
             request_data
         )
 
-        # Update the main changelog file
-        source_path = f"{repo}/CHANGELOG.md"
-        output_path = f"{output}/CHANGELOG.md"
-        _update_global_changelog(
-            source_path, output_path, libraries_to_prep_for_release
-        )
+        # TODO(https://github.com/googleapis/google-cloud-python/pull/14350):
+        # Update library global changelog file.
 
-        # Process each library to be released
+        # Prepare the release for each library by updating the
+        # library specific version files and library specific changelog.
         for library_release_data in libraries_to_prep_for_release:
-            version = library_release_data["version"]
-            library_changes = library_release_data["changes"]
-            package_name = library_release_data["id"]
-            path_to_library = f"packages/{package_name}"
-
-            # Get previous version from state.yaml
-            previous_version = _get_previous_version(repo, package_name)
-
-            _update_version_for_library(repo, output, path_to_library, version)
-            if previous_version != version:
-                _update_changelog_for_library(
-                    repo,
-                    output,
-                    library_changes,
-                    version,
-                    previous_version,
-                    package_name,
-                )
+            # TODO(https://github.com/googleapis/google-cloud-python/pull/14351):
+            # Update library specific version files.
+            # TODO(https://github.com/googleapis/google-cloud-python/pull/14352):
+            # Conditionally update the library specific CHANGELOG if there is a change.
+            pass
 
     except Exception as e:
         raise ValueError(f"Release init failed: {e}") from e
 
-
-def _get_previous_version(repo: str, package_name: str) -> str:
-    """Gets the previous version of the library from state.yaml."""
-    state_yaml_path = f"{repo}/.librarian/{STATE_YAML_FILE}"
-    if not os.path.exists(state_yaml_path):
-        raise FileNotFoundError(f"State file not found at {state_yaml_path}")
-
-    with open(state_yaml_path, "r") as state_yaml_file:
-        state_yaml = yaml.safe_load(state_yaml_file)
-        for library in state_yaml.get("libraries", []):
-            if library.get("id") == package_name:
-                return library.get("version")
-
-    raise ValueError(
-        f"Could not determine previous version for {package_name} from state.yaml"
-    )
-
-
-def _update_global_changelog(source_path: str, output_path: str, libraries: List[dict]):
-    """Updates the main CHANGELOG.md with new versions."""
-
-    def process_content(content):
-        new_content = content
-        for lib in libraries:
-            package_name = lib["id"]
-            version = lib["version"]
-            pattern = re.compile(f"(\\[{re.escape(package_name)})(==)([\\d\\.]+)(\\])")
-            replacement = f"\\g<1>=={version}\\g<4>"
-            new_content = pattern.sub(replacement, new_content)
-        return new_content
-
-    _read_and_process_file(source_path, output_path, process_content)
-
-
-def _update_changelog_for_library(
-    repo: str,
-    output: str,
-    library_changes: List[Dict],
-    version: str,
-    previous_version: str,
-    package_name: str,
-):
-    """Prepends a new release entry with multiple, grouped changes to a changelog."""
-
-    def process_content(content):
-        repo_url = "https://github.com/googleapis/google-cloud-python"
-        current_date = datetime.now().strftime("%Y-%m-%d")
-
-        # Create the main version header
-        version_header = (
-            f"## [{version}]({repo_url}/compare/{package_name}-v{previous_version}"
-            f"...{package_name}-v{version}) ({current_date})"
-        )
-        entry_parts = [version_header]
-
-        # Group changes by type (e.g., feat, fix, docs)
-        library_changes.sort(key=lambda x: x["type"])
-        grouped_changes = itertools.groupby(library_changes, key=lambda x: x["type"])
-
-        for change_type, changes in grouped_changes:
-            # We only care about feat, fix, docs
-            if change_type.replace("!", "") in ["feat", "fix", "docs"]:
-                entry_parts.append(
-                    f"\n\n### {change_type.capitalize().replace('!', '')}\n"
-                )
-                for change in changes:
-                    commit_link = f"([{change['source_commit_hash']}]({repo_url}/commit/{change['source_commit_hash']}))"
-                    entry_parts.append(f"* {change['subject']} {commit_link}")
-
-        new_entry_text = "\n".join(entry_parts)
-        anchor_pattern = re.compile(
-            r"(\[1\]: https://pypi\.org/project/google-cloud-language/#history)",
-            re.MULTILINE,
-        )
-        replacement_text = f"\\g<1>\n\n{new_entry_text}"
-        updated_content, num_subs = anchor_pattern.subn(
-            replacement_text, content, count=1
-        )
-
-        if num_subs == 0:
-            raise ValueError("Changelog anchor '[1]: ...#history' not found.")
-
-        return updated_content
-
-    source_path = f"{repo}/packages/{package_name}/CHANGELOG.md"
-    output_path = f"{output}/packages/{package_name}/CHANGELOG.md"
-    _read_and_process_file(source_path, output_path, process_content)
-
-
-def _update_version_for_library(
-    repo: str, output: str, path_to_library: str, version: str
-):
-    """Updates the version string in various files for a library."""
-
-    # Find and update gapic_version.py files
-    gapic_version_files = Path(f"{repo}/{path_to_library}").rglob("**/gapic_version.py")
-    for version_file in gapic_version_files:
-
-        def process_version_file(content):
-            pattern = r"(__version__\s*=\s*[\"'])([^\"']+)([\"'].*)"
-            replacement_string = f"\\g<1>{version}\\g<3>"
-            new_content, num_replacements = re.subn(
-                pattern, replacement_string, content
-            )
-            if num_replacements == 0:
-                raise Exception(
-                    f"Could not find version string in {version_file}. File was not modified."
-                )
-            return new_content
-
-        output_path = f"{output}/{version_file.relative_to(repo)}"
-        _read_and_process_file(str(version_file), output_path, process_version_file)
-
-    # Find and update snippet_metadata.json files
-    snippet_metadata_files = Path(f"{repo}/{path_to_library}").rglob(
-        "samples/**/*.json"
-    )
-    for metadata_file in snippet_metadata_files:
-        output_path = f"{output}/{metadata_file.relative_to(repo)}"
-        os.makedirs(Path(output_path).parent, exist_ok=True)
-        shutil.copy(metadata_file, output_path)
-
-        metadata_contents = _read_json_file(metadata_file)
-        metadata_contents["clientLibrary"]["version"] = version
-
-        with open(output_path, "w") as f:
-            json.dump(metadata_contents, f, indent=2)
-            f.write("\n")
-
+    logger.info("'release-init' command executed.")
 
 def main():
     parser = argparse.ArgumentParser(description="A simple CLI tool.")
@@ -730,21 +580,20 @@ def main():
 
     args = parser.parse_args()
 
-    # Pass arguments to the selected handler function using a dynamic approach
-    handler_args = {
-        k: v for k, v in vars(args).items() if k != "command" and k != "func"
-    }
-    # Filter out arguments not expected by the function
-    import inspect
-
-    handler_func = args.func
-    arg_spec = inspect.getfullargspec(handler_func)
-
-    valid_handler_args = {
-        k: v for k, v in handler_args.items() if k in arg_spec.args or arg_spec.varkw
-    }
-
-    handler_func(**valid_handler_args)
+    # Pass specific arguments to the handler functions for generate/build
+    if args.command == "generate":
+        args.func(
+            librarian=args.librarian,
+            source=args.source,
+            output=args.output,
+            input=args.input,
+        )
+    elif args.command == "build":
+        args.func(librarian=args.librarian, repo=args.repo)
+    elif args.command == "release-init":
+        args.func(librarian=args.librarian, repo=args.repo, output=OUTPUT_DIR)
+    else:
+        args.func()
 
 
 if __name__ == "__main__":  # pragma: NO COVER

From 26348a9a42a465229b1487f301db0d8e9d8476cb Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 10:34:51 +0000
Subject: [PATCH 03/20] remove unused code

---
 .generator/cli.py | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 7d0b235e3ace..bcf42d7a48cf 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -434,27 +434,6 @@ def handle_build(librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR):
     logger.info("'build' command executed.")
 
 
-def _read_and_process_file(input_path: str, output_path: str, process_func) -> None:
-    """Helper function to read, process, and write a file.
-
-    Args:
-        input_path (str): The path to the file to read.
-        output_path (str): The path to the file to write.
-        process_func (callable): A function that takes the file content as a string
-                                  and returns the modified string.
-    """
-    os.makedirs(Path(output_path).parent, exist_ok=True)
-    shutil.copy(input_path, output_path)
-
-    with open(output_path, "r", encoding="utf-8") as f:
-        content = f.read()
-
-    updated_content = process_func(content)
-
-    with open(output_path, "w", encoding="utf-8") as f:
-        f.write(updated_content)
-
-
 def _get_libraries_to_prepare_for_release(library_entries: Dict) -> List[dict]:
     """Note the request data may have multiple libraries in it. Locate all
     libraries which should be prepared for release. This can be done by

From 1c0ad8ac5637ebb158634552d66af787b770eee1 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 10:37:25 +0000
Subject: [PATCH 04/20] update comment

---
 .generator/cli.py | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index bcf42d7a48cf..c7499a4513d2 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -435,13 +435,12 @@ def handle_build(librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR):
 
 
 def _get_libraries_to_prepare_for_release(library_entries: Dict) -> List[dict]:
-    """Note the request data may have multiple libraries in it. Locate all
-    libraries which should be prepared for release. This can be done by
-    checking whether the `release_triggered` field is `true`.
+    """Get libraries which should be prepared for release. Only libraries
+    which have the `release_triggered` field set to `true` will be returned.
 
     Args:
-        library_entries(Dict): Dictionary containing all of the libraries
-        present in the repository.
+        library_entries(Dict): Dictionary containing all of the libraries to
+        evaluate.
 
     Returns:
         List[dict]: List of all libraries which should be prepared for release,

From c0402864d6bf6a44b28bb9dee757141f0324a2f3 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 10:38:13 +0000
Subject: [PATCH 05/20] update comment

---
 .generator/cli.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index c7499a4513d2..29b0ce1cde0e 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -436,7 +436,7 @@ def handle_build(librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR):
 
 def _get_libraries_to_prepare_for_release(library_entries: Dict) -> List[dict]:
     """Get libraries which should be prepared for release. Only libraries
-    which have the `release_triggered` field set to `true` will be returned.
+    which have the `release_triggered` field set to `True` will be returned.
 
     Args:
         library_entries(Dict): Dictionary containing all of the libraries to

From 52af9f567033a81434a83598c9585a59763ed6a4 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 10:49:31 +0000
Subject: [PATCH 06/20] wip

---
 .generator/cli.py      |  1 +
 .generator/test_cli.py | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/.generator/cli.py b/.generator/cli.py
index 29b0ce1cde0e..af94fd818d07 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -499,6 +499,7 @@ def handle_release_init(
 
     logger.info("'release-init' command executed.")
 
+
 def main():
     parser = argparse.ArgumentParser(description="A simple CLI tool.")
     subparsers = parser.add_subparsers(
diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index 74db90ee80e5..83fa00316b9f 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -23,6 +23,7 @@
 from cli import (
     GENERATE_REQUEST_FILE,
     BUILD_REQUEST_FILE,
+    RELEASE_INIT_REQUEST_FILE,
     LIBRARIAN_DIR,
     REPO_DIR,
     _build_bazel_target,
@@ -30,6 +31,7 @@
     _copy_files_needed_for_post_processing,
     _determine_bazel_rule,
     _get_library_id,
+    _get_libraries_to_prepare_for_release,
     _locate_and_extract_artifact,
     _read_json_file,
     _run_individual_session,
@@ -92,6 +94,34 @@ def mock_generate_request_data_for_nox():
     }
 
 
+@pytest.fixture
+def mock_release_init_request_file(tmp_path, monkeypatch):
+    """Creates the mock request file at the correct path inside a temp dir."""
+    # Create the path as expected by the script: .librarian/release-request.json
+    request_path = f"{LIBRARIAN_DIR}/{RELEASE_INIT_REQUEST_FILE}"
+    request_dir = tmp_path / os.path.dirname(request_path)
+    request_dir.mkdir()
+    request_file = request_dir / os.path.basename(request_path)
+
+    request_content = {
+        "libraries": [
+            {
+                "id": "google-cloud-language",
+                "apis": [{"path": "google/cloud/language/v1"}],
+                "release_triggered": True,
+                "version": "1.2.3",
+                "changes": [],
+            },
+            {},
+        ]
+    }
+    request_file.write_text(json.dumps(request_content))
+
+    # Change the current working directory to the temp path for the test.
+    monkeypatch.chdir(tmp_path)
+    return request_file
+
+
 def test_get_library_id_success():
     """Tests that _get_library_id returns the correct ID when present."""
     request_data = {"id": "test-library", "name": "Test Library"}
@@ -454,3 +484,9 @@ def test_clean_up_files_after_post_processing_success(mocker):
     mock_shutil_rmtree = mocker.patch("shutil.rmtree")
     mock_os_remove = mocker.patch("os.remove")
     _clean_up_files_after_post_processing("output", "library_id")
+
+
+def test_get_libraries_to_prepare_for_release(mock_release_init_request_file):
+    request_data = _read_json_file(f"{LIBRARIAN_DIR}/{RELEASE_INIT_REQUEST_FILE}")
+    libraries_to_prep_for_release = _get_libraries_to_prepare_for_release(request_data)
+    assert "google-cloud-language" in libraries_to_prep_for_release[0]["id"]

From e1d352b44c4ec73a2add2de8bd72ccda979bf623 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 11:04:22 +0000
Subject: [PATCH 07/20] add tests

---
 .generator/cli.py      |  8 ++------
 .generator/test_cli.py | 30 +++++++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index af94fd818d07..acb520d43405 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -500,7 +500,7 @@ def handle_release_init(
     logger.info("'release-init' command executed.")
 
 
-def main():
+if __name__ == "__main__":  # pragma: NO COVER
     parser = argparse.ArgumentParser(description="A simple CLI tool.")
     subparsers = parser.add_subparsers(
         dest="command", required=True, help="Available commands"
@@ -570,10 +570,6 @@ def main():
     elif args.command == "build":
         args.func(librarian=args.librarian, repo=args.repo)
     elif args.command == "release-init":
-        args.func(librarian=args.librarian, repo=args.repo, output=OUTPUT_DIR)
+        args.func(librarian=args.librarian, repo=args.repo, output=args.output)
     else:
         args.func()
-
-
-if __name__ == "__main__":  # pragma: NO COVER
-    main()
diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index 83fa00316b9f..c2ee8f22f74b 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -40,6 +40,7 @@
     handle_build,
     handle_configure,
     handle_generate,
+    handle_release_init,
 )
 
 
@@ -105,6 +106,13 @@ def mock_release_init_request_file(tmp_path, monkeypatch):
 
     request_content = {
         "libraries": [
+            {
+                "id": "google-cloud-another-library",
+                "apis": [{"path": "google/cloud/another/library/v1"}],
+                "release_triggered": False,
+                "version": "1.2.3",
+                "changes": [],
+            },
             {
                 "id": "google-cloud-language",
                 "apis": [{"path": "google/cloud/language/v1"}],
@@ -112,7 +120,6 @@ def mock_release_init_request_file(tmp_path, monkeypatch):
                 "version": "1.2.3",
                 "changes": [],
             },
-            {},
         ]
     }
     request_file.write_text(json.dumps(request_content))
@@ -487,6 +494,27 @@ def test_clean_up_files_after_post_processing_success(mocker):
 
 
 def test_get_libraries_to_prepare_for_release(mock_release_init_request_file):
+    """
+    Tests that only libraries with the `release_triggered` field set to `True` are
+    returned.
+    """
     request_data = _read_json_file(f"{LIBRARIAN_DIR}/{RELEASE_INIT_REQUEST_FILE}")
     libraries_to_prep_for_release = _get_libraries_to_prepare_for_release(request_data)
+    assert len(libraries_to_prep_for_release) == 1
     assert "google-cloud-language" in libraries_to_prep_for_release[0]["id"]
+    assert libraries_to_prep_for_release[0]["id"]["release_triggered"]
+
+
+def test_handle_release_init_success(mock_release_init_request_file):
+    """
+    Simply tests that `handle_release_init` runs without errors.
+    """
+    handle_release_init()
+
+
+def test_handle_release_init_fail():
+    """
+    Tests that handle_release_init fails to read `librarian/release-init-request.json`.
+    """
+    with pytest.raises(ValueError):
+        handle_release_init()

From bd770deab578f129d655c8ef54921e7416f12928 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 11:05:25 +0000
Subject: [PATCH 08/20] update comment

---
 .generator/cli.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index acb520d43405..fa9c8ec62eed 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -456,7 +456,7 @@ def _get_libraries_to_prepare_for_release(library_entries: Dict) -> List[dict]:
 def handle_release_init(
     librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR, output: str = OUTPUT_DIR
 ):
-    """The main coordinator for the release process.
+    """The main coordinator for the release preparation process.
 
     This function prepares for the release of client libraries by reading a
     `librarian/release-init-request.json` file. The primary responsibility is

From 96934d9cb2e583f3aa37c448bfbd09ea19b5c1dc Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 11:05:49 +0000
Subject: [PATCH 09/20] update comment

---
 .generator/cli.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index fa9c8ec62eed..108e96a04bab 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -461,7 +461,7 @@ def handle_release_init(
     This function prepares for the release of client libraries by reading a
     `librarian/release-init-request.json` file. The primary responsibility is
     to update all required files with the new version and commit information
-    for libraries that have the `release_triggered` field set to `true`.
+    for libraries that have the `release_triggered` field set to `True`.
 
     See https://github.com/googleapis/librarian/blob/main/doc/container-contract.md#generate-container-command
 

From f6314b06bd09f64614c7bf940bc8746be8bdb895 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 11:06:02 +0000
Subject: [PATCH 10/20] update comment

---
 .generator/cli.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 108e96a04bab..8d7b305ea7e4 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -467,7 +467,7 @@ def handle_release_init(
 
     Args:
         librarian(str): Path to the directory in the container which contains
-            the `release-init-request.json` file
+            the `release-init-request.json` file.
         repo(str): This directory will contain all directories that make up a
             library, the .librarian folder, and any global file declared in
             the config.yaml.

From 788a7aeae7951fc2a13330911c774e5d06a3362d Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 11:08:20 +0000
Subject: [PATCH 11/20] fix typo

---
 .generator/test_cli.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index c2ee8f22f74b..cf43ccd0745c 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -502,7 +502,7 @@ def test_get_libraries_to_prepare_for_release(mock_release_init_request_file):
     libraries_to_prep_for_release = _get_libraries_to_prepare_for_release(request_data)
     assert len(libraries_to_prep_for_release) == 1
     assert "google-cloud-language" in libraries_to_prep_for_release[0]["id"]
-    assert libraries_to_prep_for_release[0]["id"]["release_triggered"]
+    assert libraries_to_prep_for_release[0]["release_triggered"]
 
 
 def test_handle_release_init_success(mock_release_init_request_file):

From 9240a7cdc7c4fc231f3e2c34259a3a19fe51c42b Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 11:11:23 +0000
Subject: [PATCH 12/20] update pull request nunmbers

---
 .generator/cli.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 8d7b305ea7e4..6b77a54c37b0 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -482,15 +482,15 @@ def handle_release_init(
             request_data
         )
 
-        # TODO(https://github.com/googleapis/google-cloud-python/pull/14350):
+        # TODO(https://github.com/googleapis/google-cloud-python/pull/14349):
         # Update library global changelog file.
 
         # Prepare the release for each library by updating the
         # library specific version files and library specific changelog.
         for library_release_data in libraries_to_prep_for_release:
-            # TODO(https://github.com/googleapis/google-cloud-python/pull/14351):
+            # TODO(https://github.com/googleapis/google-cloud-python/pull/14350):
             # Update library specific version files.
-            # TODO(https://github.com/googleapis/google-cloud-python/pull/14352):
+            # TODO(https://github.com/googleapis/google-cloud-python/pull/14351):
             # Conditionally update the library specific CHANGELOG if there is a change.
             pass
 

From 0691dacddcb423f7e2e2c759fcea3dada8d2c454 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 14:11:31 +0000
Subject: [PATCH 13/20] chore: add ability to update the global changelog via
 release-init command

---
 .generator/cli.py      | 72 ++++++++++++++++++++++++++++++++++++++++--
 .generator/test_cli.py | 57 +++++++++++++++++++++++++++++++--
 2 files changed, 125 insertions(+), 4 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 6b77a54c37b0..b68583fac563 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -47,6 +47,43 @@
 SOURCE_DIR = "source"
 
 
+def _read_text_file(path: str) -> str:
+    """Helper function that reads a text file path and returns the content.
+
+    Args:
+        path(str): The file path to read.
+
+    Returns:
+        str: The contents of the file.
+
+    Raises:
+        FileNotFoundError: If the file is not found at the specified path.
+        IOError: If there is an issue reading the file.
+    """
+
+    with open(path, "r") as f:
+        return f.read()
+
+
+def _write_text_file(path: str, updated_content: str) -> str:
+    """Helper function that reads a text file path and returns the content.
+
+    Args:
+        path(str): The file path to read.
+        updated_content(str): The contents to write to the file.
+
+    Returns:
+        None
+
+    Raises:
+        FileNotFoundError: If the file is not found at the specified path.
+        IOError: If there is an issue writing the file.
+    """
+
+    with open(path, "w") as f:
+        f.write(updated_content)
+
+
 def _read_json_file(path: str) -> Dict:
     """Helper function that reads a json file path and returns the loaded json content.
 
@@ -453,6 +490,34 @@ def _get_libraries_to_prepare_for_release(library_entries: Dict) -> List[dict]:
     ]
 
 
+def _update_global_changelog(source_path: str, output_path: str, libraries: List[dict]):
+    """Updates the versions of libraries in the main CHANGELOG.md.
+
+    Args:
+        source_path(str): Path to the changelog file to read.
+        output_path(str): Path to the changelog file to write.
+        libraries(Dict): Dictionary containing all of the library versions to
+        modify.
+
+    Returns: None
+    """
+
+    def replace_version_in_changelog(content):
+        new_content = content
+        for individual_library in libraries:
+            package_name = individual_library["id"]
+            version = individual_library["version"]
+            # Find the entry for the given package in the format`<package name>==<version>`
+            # Replace the `<version>` part of the string.
+            pattern = re.compile(f"(\\[{re.escape(package_name)})(==)([\\d\\.]+)(\\])")
+            replacement = f"\\g<1>=={version}\\g<4>"
+            new_content = pattern.sub(replacement, new_content)
+        return new_content
+
+    updated_content = replace_version_in_changelog(_read_text_file(source_path))
+    _write_text_file(output_path, updated_content)
+
+
 def handle_release_init(
     librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR, output: str = OUTPUT_DIR
 ):
@@ -482,8 +547,11 @@ def handle_release_init(
             request_data
         )
 
-        # TODO(https://github.com/googleapis/google-cloud-python/pull/14349):
-        # Update library global changelog file.
+        _update_global_changelog(
+            f"{repo}/CHANGELOG.md",
+            f"{output}/CHANGELOG.md",
+            libraries_to_prep_for_release,
+        )
 
         # Prepare the release for each library by updating the
         # library specific version files and library specific changelog.
diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index cf43ccd0745c..5e8b8c043e21 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -16,6 +16,7 @@
 import logging
 import os
 import subprocess
+import unittest.mock
 from unittest.mock import MagicMock, mock_open
 
 import pytest
@@ -34,9 +35,12 @@
     _get_libraries_to_prepare_for_release,
     _locate_and_extract_artifact,
     _read_json_file,
+    _read_text_file,
     _run_individual_session,
     _run_nox_sessions,
     _run_post_processor,
+    _update_global_changelog,
+    _write_text_file,
     handle_build,
     handle_configure,
     handle_generate,
@@ -461,7 +465,7 @@ def test_read_valid_json(mocker):
     assert result == {"key": "value"}
 
 
-def test_file_not_found(mocker):
+def test_json_file_not_found(mocker):
     """Tests behavior when the file does not exist."""
     mocker.patch("builtins.open", side_effect=FileNotFoundError("No such file"))
 
@@ -505,10 +509,11 @@ def test_get_libraries_to_prepare_for_release(mock_release_init_request_file):
     assert libraries_to_prep_for_release[0]["release_triggered"]
 
 
-def test_handle_release_init_success(mock_release_init_request_file):
+def test_handle_release_init_success(mocker, mock_release_init_request_file):
     """
     Simply tests that `handle_release_init` runs without errors.
     """
+    mocker.patch("cli._update_global_changelog", return_value=None)
     handle_release_init()
 
 
@@ -518,3 +523,51 @@ def test_handle_release_init_fail():
     """
     with pytest.raises(ValueError):
         handle_release_init()
+
+
+def test_read_valid_file(mocker):
+    """Tests reading a valid text file."""
+    mock_content = "some text"
+    mocker.patch("builtins.open", mocker.mock_open(read_data=mock_content))
+    result = _read_text_file("fake/path.txt")
+    assert result == "some text"
+
+
+def test_text_file_not_found(mocker):
+    """Tests behavior when the file does not exist."""
+    mocker.patch("builtins.open", side_effect=FileNotFoundError("No such file"))
+
+    with pytest.raises(FileNotFoundError):
+        _read_text_file("non/existent/path.text")
+
+
+def test_write_file():
+    """Tests writing a text file.
+    See https://docs.python.org/3/library/unittest.mock.html#mock-open
+    """
+    m = mock_open()
+
+    with unittest.mock.patch("cli.open", m):
+        _write_text_file("fake_path.txt", "modified content")
+
+        handle = m()
+        handle.write.assert_called_once_with("modified content")
+
+
+def test_update_global_changelog(mocker, mock_release_init_request_file):
+    """Tests that the global changelog is updated
+    with the new version for a given library.
+    See https://docs.python.org/3/library/unittest.mock.html#mock-open
+    """
+    m = mock_open()
+    request_data = _read_json_file(f"{LIBRARIAN_DIR}/{RELEASE_INIT_REQUEST_FILE}")
+    libraries = _get_libraries_to_prepare_for_release(request_data)
+
+    with unittest.mock.patch("cli.open", m):
+        mocker.patch(
+            "cli._read_text_file", return_value="[google-cloud-language==1.2.2]"
+        )
+        _update_global_changelog("source", "output", libraries)
+
+        handle = m()
+        handle.write.assert_called_once_with("[google-cloud-language==1.2.3]")

From 6e45c59e2c3fd7e3dc1c48757a3a38c5b7fb12f9 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 14:26:20 +0000
Subject: [PATCH 14/20] fix typo

---
 .generator/cli.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index b68583fac563..ee97deccc3b7 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -65,7 +65,7 @@ def _read_text_file(path: str) -> str:
         return f.read()
 
 
-def _write_text_file(path: str, updated_content: str) -> str:
+def _write_text_file(path: str, updated_content: str):
     """Helper function that reads a text file path and returns the content.
 
     Args:

From 289382e1eae0dffeade8a97a58c672726ace3052 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 14:27:44 +0000
Subject: [PATCH 15/20] typo

---
 .generator/cli.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index ee97deccc3b7..050d87719986 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -66,10 +66,10 @@ def _read_text_file(path: str) -> str:
 
 
 def _write_text_file(path: str, updated_content: str):
-    """Helper function that reads a text file path and returns the content.
+    """Helper function that writes a text file path with the given content.
 
     Args:
-        path(str): The file path to read.
+        path(str): The file path to write.
         updated_content(str): The contents to write to the file.
 
     Returns:

From 7fe73bec24132f29d8b6ed7c66300bf2859fd080 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 17:05:02 +0000
Subject: [PATCH 16/20] chore: add ability to update library specific version
 files in release-init command

---
 .generator/cli.py      | 78 +++++++++++++++++++++++++++++++++++++++--
 .generator/test_cli.py | 79 ++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 153 insertions(+), 4 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 050d87719986..47d66779f998 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -102,6 +102,26 @@ def _read_json_file(path: str) -> Dict:
         return json.load(f)
 
 
+def _write_json_file(path: str, updated_content: Dict):
+    """Helper function that writes a json file with the given dictionary.
+
+    Args:
+        path(str): The file path to write.
+        updated_content(Dict): The dictionary to write
+
+    Returns:
+        None
+
+    Raises:
+        FileNotFoundError: If the file is not found at the specified path.
+        IOError: If there is an issue writing the file.
+    """
+
+    with open(path, "w") as f:
+        json.dump(updated_content, f, indent=2)
+        f.write("\n")
+
+
 def handle_configure():
     # TODO(https://github.com/googleapis/librarian/issues/466): Implement configure command and update docstring.
     logger.info("'configure' command executed.")
@@ -518,6 +538,57 @@ def replace_version_in_changelog(content):
     _write_text_file(output_path, updated_content)
 
 
+def _update_version_for_library(
+    repo: str, output: str, path_to_library: str, version: str
+):
+    """Updates the version string in various files for a library, such as
+    gapic_version.py and snippet_metadata.json files.
+
+    Args:
+        repo(str): This directory will contain all directories that make up a
+            library, the .librarian folder, and any global file declared in
+            the config.yaml.
+        output(str): Path to the directory in the container where modified
+            code should be placed.
+        path_to_library(str): Relative path to the library to update
+        version(str): The new version of the library
+    """
+
+    # Find and update gapic_version.py files
+    gapic_version_files = Path(f"{repo}/{path_to_library}").rglob("**/gapic_version.py")
+    for version_file in gapic_version_files:
+
+        def process_version_file(content):
+            pattern = r"(__version__\s*=\s*[\"'])([^\"']+)([\"'].*)"
+            replacement_string = f"\\g<1>{version}\\g<3>"
+            new_content, num_replacements = re.subn(
+                pattern, replacement_string, content
+            )
+            print(content)
+            if num_replacements == 0:
+                raise ValueError(
+                    f"Could not find version string in {version_file}. File was not modified."
+                )
+            return new_content
+
+        updated_content = process_version_file(_read_text_file(version_file))
+        output_path = f"{output}/{version_file.relative_to(repo)}"
+        _write_text_file(output_path, updated_content)
+
+    # Find and update snippet_metadata.json files
+    snippet_metadata_files = Path(f"{repo}/{path_to_library}").rglob(
+        "samples/**/*.json"
+    )
+    for metadata_file in snippet_metadata_files:
+        output_path = f"{output}/{metadata_file.relative_to(repo)}"
+        os.makedirs(Path(output_path).parent, exist_ok=True)
+        shutil.copy(metadata_file, output_path)
+
+        metadata_contents = _read_json_file(metadata_file)
+        metadata_contents["clientLibrary"]["version"] = version
+        _write_json_file(output_path, metadata_contents)
+
+
 def handle_release_init(
     librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR, output: str = OUTPUT_DIR
 ):
@@ -556,8 +627,11 @@ def handle_release_init(
         # Prepare the release for each library by updating the
         # library specific version files and library specific changelog.
         for library_release_data in libraries_to_prep_for_release:
-            # TODO(https://github.com/googleapis/google-cloud-python/pull/14350):
-            # Update library specific version files.
+            version = library_release_data["version"]
+            package_name = library_release_data["id"]
+            path_to_library = f"packages/{package_name}"
+            _update_version_for_library(repo, output, path_to_library, version)
+
             # TODO(https://github.com/googleapis/google-cloud-python/pull/14351):
             # Conditionally update the library specific CHANGELOG if there is a change.
             pass
diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index 5e8b8c043e21..13e4e65758bf 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -15,12 +15,12 @@
 import json
 import logging
 import os
+import pathlib
 import subprocess
 import unittest.mock
 from unittest.mock import MagicMock, mock_open
 
 import pytest
-
 from cli import (
     GENERATE_REQUEST_FILE,
     BUILD_REQUEST_FILE,
@@ -40,6 +40,8 @@
     _run_nox_sessions,
     _run_post_processor,
     _update_global_changelog,
+    _update_version_for_library,
+    _write_json_file,
     _write_text_file,
     handle_build,
     handle_configure,
@@ -514,6 +516,7 @@ def test_handle_release_init_success(mocker, mock_release_init_request_file):
     Simply tests that `handle_release_init` runs without errors.
     """
     mocker.patch("cli._update_global_changelog", return_value=None)
+    mocker.patch("cli._update_version_for_library", return_value=None)
     handle_release_init()
 
 
@@ -541,7 +544,7 @@ def test_text_file_not_found(mocker):
         _read_text_file("non/existent/path.text")
 
 
-def test_write_file():
+def test_write_text_file():
     """Tests writing a text file.
     See https://docs.python.org/3/library/unittest.mock.html#mock-open
     """
@@ -554,6 +557,31 @@ def test_write_file():
         handle.write.assert_called_once_with("modified content")
 
 
+def test_write_json_file():
+    """Tests writing a json file.
+    See https://docs.python.org/3/library/unittest.mock.html#mock-open
+    """
+    m = mock_open()
+
+    expected_dict = {"name": "call me json"}
+
+    with unittest.mock.patch("cli.open", m):
+        _write_json_file("fake_path.json", expected_dict)
+
+        handle = m()
+        # Get all the arguments passed to the mock's write method
+        # and join them into a single string.
+        written_content = "".join(
+            [call.args[0] for call in handle.write.call_args_list]
+        )
+
+        # Create the expected output string with the correct formatting.
+        expected_output = json.dumps(expected_dict, indent=2) + "\n"
+
+        # Assert that the content written to the mock file matches the expected output.
+        assert written_content == expected_output
+
+
 def test_update_global_changelog(mocker, mock_release_init_request_file):
     """Tests that the global changelog is updated
     with the new version for a given library.
@@ -571,3 +599,50 @@ def test_update_global_changelog(mocker, mock_release_init_request_file):
 
         handle = m()
         handle.write.assert_called_once_with("[google-cloud-language==1.2.3]")
+
+
+def test_update_version_for_library_success(mocker):
+    m = mock_open()
+
+    mock_rglob = mocker.patch(
+        "pathlib.Path.rglob", return_value=[pathlib.Path("repo/gapic_version.py")]
+    )
+    mock_shutil_copy = mocker.patch("shutil.copy")
+    mock_content = '__version__ = "1.2.2"'
+    mock_json_metadata = {"clientLibrary": {"version": "0.1.0"}}
+
+    with unittest.mock.patch("cli.open", m):
+        mocker.patch("cli._read_text_file", return_value=mock_content)
+        mocker.patch("cli._read_json_file", return_value=mock_json_metadata)
+        _update_version_for_library(
+            "repo", "output", "packages/google-cloud-language", "1.2.3"
+        )
+
+        handle = m()
+        assert handle.write.call_args_list[0].args[0] == '__version__ = "1.2.3"'
+
+        # Get all the arguments passed to the mock's write method
+        # and join them into a single string.
+        written_content = "".join(
+            [call.args[0] for call in handle.write.call_args_list[1:]]
+        )
+        # Create the expected output string with the correct formatting.
+        assert (
+            written_content
+            == '{\n  "clientLibrary": {\n    "version": "1.2.3"\n  }\n}\n'
+        )
+
+
+def test_update_version_for_library_failure(mocker):
+    m = mock_open()
+
+    mock_rglob = mocker.patch(
+        "pathlib.Path.rglob", return_value=[pathlib.Path("repo/gapic_version.py")]
+    )
+    mock_content = "not found"
+    with pytest.raises(ValueError):
+        with unittest.mock.patch("cli.open", m):
+            mocker.patch("cli._read_text_file", return_value=mock_content)
+            _update_version_for_library(
+                "repo", "output", "packages/google-cloud-language", "1.2.3"
+            )

From d8eda94565ae3dcf5767185cffc96e131e1f662b Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Wed, 3 Sep 2025 18:07:35 +0000
Subject: [PATCH 17/20] chore: add ability to update library specific changelog
 in release-init

---
 .generator/cli.py      | 113 +++++++++++++++++++++++++++++++++++++++--
 .generator/test_cli.py | 109 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 219 insertions(+), 3 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 47d66779f998..8464b0197b94 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -14,6 +14,7 @@
 
 import argparse
 import glob
+import itertools
 import json
 import logging
 import os
@@ -21,6 +22,8 @@
 import shutil
 import subprocess
 import sys
+import yaml
+from datetime import datetime
 from pathlib import Path
 from typing import Dict, List
 
@@ -39,6 +42,7 @@
 BUILD_REQUEST_FILE = "build-request.json"
 GENERATE_REQUEST_FILE = "generate-request.json"
 RELEASE_INIT_REQUEST_FILE = "release-init-request.json"
+STATE_YAML_FILE = "state.yaml"
 
 INPUT_DIR = "input"
 LIBRARIAN_DIR = "librarian"
@@ -589,6 +593,100 @@ def process_version_file(content):
         _write_json_file(output_path, metadata_contents)
 
 
+def _get_previous_version(package_name: str, librarian: str) -> str:
+    """Gets the previous version of the library from state.yaml.
+
+    Args:
+        package_name(str): name of the package.
+        librarian(str): Path to the directory in the container which contains
+            the `state.yaml` file.
+
+    Returns:
+        str: The version for a given library in state.yaml
+    """
+    state_yaml_path = f"{librarian}/{STATE_YAML_FILE}"
+
+    with open(state_yaml_path, "r") as state_yaml_file:
+        state_yaml = yaml.safe_load(state_yaml_file)
+        for library in state_yaml.get("libraries", []):
+            if library.get("id") == package_name:
+                return library.get("version")
+
+    raise ValueError(
+        f"Could not determine previous version for {package_name} from state.yaml"
+    )
+
+
+def _update_changelog_for_library(
+    repo: str,
+    output: str,
+    library_changes: List[Dict],
+    version: str,
+    previous_version: str,
+    package_name: str,
+):
+    """Prepends a new release entry with multiple, grouped changes to a changelog.
+
+    Args:
+        repo(str): This directory will contain all directories that make up a
+            library, the .librarian folder, and any global file declared in
+            the config.yaml.
+        output(str): Path to the directory in the container where modified
+            code should be placed.
+        library_changes(List[Dict]): List of dictionaries containing the changes
+            for a given library
+        version(str): The desired version
+        previous_version(str): The version in state.yaml for a given package
+        package_name(str): The name of the package where the changelog should
+            be updated.
+    """
+
+    def process_changelog(content):
+        repo_url = "https://github.com/googleapis/google-cloud-python"
+        current_date = datetime.now().strftime("%Y-%m-%d")
+
+        # Create the main version header
+        version_header = (
+            f"## [{version}]({repo_url}/compare/{package_name}-v{previous_version}"
+            f"...{package_name}-v{version}) ({current_date})"
+        )
+        entry_parts = [version_header]
+
+        # Group changes by type (e.g., feat, fix, docs)
+        library_changes.sort(key=lambda x: x["type"])
+        grouped_changes = itertools.groupby(library_changes, key=lambda x: x["type"])
+
+        for change_type, changes in grouped_changes:
+            # We only care about feat, fix, docs
+            if change_type.replace("!", "") in ["feat", "fix", "docs"]:
+                entry_parts.append(
+                    f"\n\n### {change_type.capitalize().replace('!', '')}\n"
+                )
+                for change in changes:
+                    commit_link = f"([{change['source_commit_hash']}]({repo_url}/commit/{change['source_commit_hash']}))"
+                    entry_parts.append(f"* {change['subject']} {commit_link}")
+
+        new_entry_text = "\n".join(entry_parts)
+        anchor_pattern = re.compile(
+            r"(\[1\]: https://pypi\.org/project/google-cloud-language/#history)",
+            re.MULTILINE,
+        )
+        replacement_text = f"\\g<1>\n\n{new_entry_text}"
+        updated_content, num_subs = anchor_pattern.subn(
+            replacement_text, content, count=1
+        )
+
+        if num_subs == 0:
+            raise ValueError("Changelog anchor '[1]: ...#history' not found.")
+
+        return updated_content
+
+    source_path = f"{repo}/packages/{package_name}/CHANGELOG.md"
+    output_path = f"{output}/packages/{package_name}/CHANGELOG.md"
+    updated_content = process_changelog(_read_text_file(source_path))
+    _write_text_file(output_path, updated_content)
+
+
 def handle_release_init(
     librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR, output: str = OUTPUT_DIR
 ):
@@ -629,12 +727,21 @@ def handle_release_init(
         for library_release_data in libraries_to_prep_for_release:
             version = library_release_data["version"]
             package_name = library_release_data["id"]
+            library_changes = library_release_data["changes"]
             path_to_library = f"packages/{package_name}"
             _update_version_for_library(repo, output, path_to_library, version)
 
-            # TODO(https://github.com/googleapis/google-cloud-python/pull/14351):
-            # Conditionally update the library specific CHANGELOG if there is a change.
-            pass
+            # Get previous version from state.yaml
+            previous_version = _get_previous_version(package_name, librarian)
+            if previous_version != version:
+                _update_changelog_for_library(
+                    repo,
+                    output,
+                    library_changes,
+                    version,
+                    previous_version,
+                    package_name,
+                )
 
     except Exception as e:
         raise ValueError(f"Release init failed: {e}") from e
diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index 13e4e65758bf..d77278acd889 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -17,6 +17,7 @@
 import os
 import pathlib
 import subprocess
+import yaml
 import unittest.mock
 from unittest.mock import MagicMock, mock_open
 
@@ -25,6 +26,7 @@
     GENERATE_REQUEST_FILE,
     BUILD_REQUEST_FILE,
     RELEASE_INIT_REQUEST_FILE,
+    STATE_YAML_FILE,
     LIBRARIAN_DIR,
     REPO_DIR,
     _build_bazel_target,
@@ -33,12 +35,14 @@
     _determine_bazel_rule,
     _get_library_id,
     _get_libraries_to_prepare_for_release,
+    _get_previous_version,
     _locate_and_extract_artifact,
     _read_json_file,
     _read_text_file,
     _run_individual_session,
     _run_nox_sessions,
     _run_post_processor,
+    _update_changelog_for_library,
     _update_global_changelog,
     _update_version_for_library,
     _write_json_file,
@@ -135,6 +139,25 @@ def mock_release_init_request_file(tmp_path, monkeypatch):
     return request_file
 
 
+@pytest.fixture
+def mock_state_file(tmp_path, monkeypatch):
+    """Creates the state file at the correct path inside a temp dir."""
+    # Create the path as expected by the script: .librarian/state.yaml
+    request_path = f"{LIBRARIAN_DIR}/{STATE_YAML_FILE}"
+    request_dir = tmp_path / os.path.dirname(request_path)
+    request_dir.mkdir()
+    request_file = request_dir / os.path.basename(request_path)
+
+    state_yaml_contents = {
+        "libraries": [{"id": "google-cloud-language", "version": "1.2.3"}]
+    }
+    request_file.write_text(yaml.dump(state_yaml_contents))
+
+    # Change the current working directory to the temp path for the test.
+    monkeypatch.chdir(tmp_path)
+    return request_file
+
+
 def test_get_library_id_success():
     """Tests that _get_library_id returns the correct ID when present."""
     request_data = {"id": "test-library", "name": "Test Library"}
@@ -517,6 +540,8 @@ def test_handle_release_init_success(mocker, mock_release_init_request_file):
     """
     mocker.patch("cli._update_global_changelog", return_value=None)
     mocker.patch("cli._update_version_for_library", return_value=None)
+    mocker.patch("cli._get_previous_version", return_value=None)
+    mocker.patch("cli._update_changelog_for_library", return_value=None)
     handle_release_init()
 
 
@@ -646,3 +671,87 @@ def test_update_version_for_library_failure(mocker):
             _update_version_for_library(
                 "repo", "output", "packages/google-cloud-language", "1.2.3"
             )
+
+
+def test_get_previous_version_success(mock_state_file):
+    """Test that the version can be retrieved from the state.yaml for a given library"""
+    previous_version = _get_previous_version("google-cloud-language", LIBRARIAN_DIR)
+    assert previous_version == "1.2.3"
+
+
+def test_get_previous_version_failure(mock_state_file):
+    """Test that ValueError is raised when a library does not exist in state.yaml"""
+    with pytest.raises(ValueError):
+        _get_previous_version("google-cloud-does-not-exist", LIBRARIAN_DIR)
+
+
+def test_update_changelog_for_library_success(mocker):
+    m = mock_open()
+
+    mock_content = """# Changelog
+
+[PyPI History][1]
+
+[1]: https://pypi.org/project/google-cloud-language/#history
+
+## [2.17.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v2.17.1...google-cloud-language-v2.17.2) (2025-06-11)
+
+"""
+
+    mock_changes = [
+        {
+            "type": "feat",
+            "subject": "add new UpdateRepository API",
+            "body": "This adds the ability to update a repository's properties.",
+            "piper_cl_number": "786353207",
+            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+        {
+            "type": "docs",
+            "subject": "fix typo in BranchRule comment",
+            "body": "",
+            "piper_cl_number": "786353207",
+            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+    ]
+
+    with unittest.mock.patch("cli.open", m):
+        mocker.patch("cli._read_text_file", return_value=mock_content)
+        _update_changelog_for_library(
+            "repo", "output", mock_changes, "1.2.3", "1.2.2", "google-cloud-language"
+        )
+
+
+def test_update_changelog_for_library_failure(mocker):
+    m = mock_open()
+
+    mock_content = """# Changelog"""
+
+    mock_changes = [
+        {
+            "type": "feat",
+            "subject": "add new UpdateRepository API",
+            "body": "This adds the ability to update a repository's properties.",
+            "piper_cl_number": "786353207",
+            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+        {
+            "type": "docs",
+            "subject": "fix typo in BranchRule comment",
+            "body": "",
+            "piper_cl_number": "786353207",
+            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+    ]
+
+    with pytest.raises(ValueError):
+        with unittest.mock.patch("cli.open", m):
+            mocker.patch("cli._read_text_file", return_value=mock_content)
+            _update_changelog_for_library(
+                "repo",
+                "output",
+                mock_changes,
+                "1.2.3",
+                "1.2.2",
+                "google-cloud-language",
+            )

From 8365905746b0daa0742c15abf17c606904c264d8 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Fri, 5 Sep 2025 15:56:10 +0000
Subject: [PATCH 18/20] refactor

---
 .generator/cli.py      | 119 ++++++++++++++++++++++++++---------------
 .generator/test_cli.py |  62 +++++++++++++++++++++
 2 files changed, 139 insertions(+), 42 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index a0e96c577d47..8c86c4831433 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -606,6 +606,75 @@ def _get_previous_version(package_name: str, librarian: str) -> str:
     )
 
 
+def _process_changelog(
+    content, library_changes, version, previous_version, package_name
+):
+    """This function searches the given content for the anchor pattern
+    `[1]: https://pypi.org/project/{package_name}/#history`
+    and adds an entry in the following format:
+
+    ## [{version}](https://github.com/googleapis/google-cloud-python/compare/{package_name}-v{previous_version}...{package_name}-v{version}) (YYYY-MM-DD)
+
+    ### Documentation
+
+    * Update import statement example in README ([868b006](https://github.com/googleapis/google-cloud-python/commit/868b0069baf1a4bf6705986e0b6885419b35cdcc))
+
+    Args:
+        content(str): The contents of an existing changelog.
+        library_changes(List[Dict]): List of dictionaries containing the changes
+            for a given library.
+        version(str): The new version of the library.
+        previous_version: The previous version of the library.
+        package_name(str): The name of the package where the changelog should
+            be updated.
+
+    Raises: ValueError if the anchor pattern string could not be found in the given content
+
+    Returns: A string with the modified content.
+    """
+    repo_url = "https://github.com/googleapis/google-cloud-python"
+    current_date = datetime.now().strftime("%Y-%m-%d")
+
+    # Create the main version header
+    version_header = (
+        f"## [{version}]({repo_url}/compare/{package_name}-v{previous_version}"
+        f"...{package_name}-v{version}) ({current_date})"
+    )
+    entry_parts = [version_header]
+
+    # Group changes by type (e.g., feat, fix, docs)
+    library_changes.sort(key=lambda x: x["type"])
+    grouped_changes = itertools.groupby(library_changes, key=lambda x: x["type"])
+
+    for change_type, changes in grouped_changes:
+        # We only care about feat, fix, docs
+        adjusted_change_type = change_type.replace("!", "")
+        if adjusted_change_type in ["feat", "fix", "docs"]:
+            if adjusted_change_type == "feat":
+                adjusted_change_type = "Features"
+            elif adjusted_change_type == "fix":
+                adjusted_change_type = "Bug Fixes"
+            else:
+                adjusted_change_type = "Documentation"
+
+            entry_parts.append(f"\n\n### {adjusted_change_type}\n")
+            for change in changes:
+                commit_link = f"([{change['source_commit_hash']}]({repo_url}/commit/{change['source_commit_hash']}))"
+                entry_parts.append(f"* {change['subject']} {commit_link}")
+
+    new_entry_text = "\n".join(entry_parts)
+    anchor_pattern = re.compile(
+        rf"(\[1\]: https://pypi\.org/project/{package_name}/#history)",
+        re.MULTILINE,
+    )
+    replacement_text = f"\\g<1>\n\n{new_entry_text}"
+    updated_content, num_subs = anchor_pattern.subn(replacement_text, content, count=1)
+    if num_subs == 0:
+        raise ValueError("Changelog anchor '[1]: ...#history' not found.")
+
+    return updated_content
+
+
 def _update_changelog_for_library(
     repo: str,
     output: str,
@@ -614,7 +683,7 @@ def _update_changelog_for_library(
     previous_version: str,
     package_name: str,
 ):
-    """Prepends a new release entry with multiple, grouped changes to a changelog.
+    """Prepends a new release entry with multiple, grouped changes, to a changelog.
 
     Args:
         repo(str): This directory will contain all directories that make up a
@@ -630,49 +699,15 @@ def _update_changelog_for_library(
             be updated.
     """
 
-    def process_changelog(content):
-        repo_url = "https://github.com/googleapis/google-cloud-python"
-        current_date = datetime.now().strftime("%Y-%m-%d")
-
-        # Create the main version header
-        version_header = (
-            f"## [{version}]({repo_url}/compare/{package_name}-v{previous_version}"
-            f"...{package_name}-v{version}) ({current_date})"
-        )
-        entry_parts = [version_header]
-
-        # Group changes by type (e.g., feat, fix, docs)
-        library_changes.sort(key=lambda x: x["type"])
-        grouped_changes = itertools.groupby(library_changes, key=lambda x: x["type"])
-
-        for change_type, changes in grouped_changes:
-            # We only care about feat, fix, docs
-            if change_type.replace("!", "") in ["feat", "fix", "docs"]:
-                entry_parts.append(
-                    f"\n\n### {change_type.capitalize().replace('!', '')}\n"
-                )
-                for change in changes:
-                    commit_link = f"([{change['source_commit_hash']}]({repo_url}/commit/{change['source_commit_hash']}))"
-                    entry_parts.append(f"* {change['subject']} {commit_link}")
-
-        new_entry_text = "\n".join(entry_parts)
-        anchor_pattern = re.compile(
-            r"(\[1\]: https://pypi\.org/project/google-cloud-language/#history)",
-            re.MULTILINE,
-        )
-        replacement_text = f"\\g<1>\n\n{new_entry_text}"
-        updated_content, num_subs = anchor_pattern.subn(
-            replacement_text, content, count=1
-        )
-
-        if num_subs == 0:
-            raise ValueError("Changelog anchor '[1]: ...#history' not found.")
-
-        return updated_content
-
     source_path = f"{repo}/packages/{package_name}/CHANGELOG.md"
     output_path = f"{output}/packages/{package_name}/CHANGELOG.md"
-    updated_content = process_changelog(_read_text_file(source_path))
+    updated_content = _process_changelog(
+        _read_text_file(source_path),
+        library_changes,
+        version,
+        previous_version,
+        package_name,
+    )
     _write_text_file(output_path, updated_content)
 
 
diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index 8081e2cfea6e..df23fe3979dc 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -37,6 +37,7 @@
     _get_libraries_to_prepare_for_release,
     _get_previous_version,
     _locate_and_extract_artifact,
+    _process_changelog,
     _process_version_file,
     _read_json_file,
     _read_text_file,
@@ -724,6 +725,66 @@ def test_update_changelog_for_library_success(mocker):
         )
 
 
+def test_process_changelog_success():
+    """Tests that value error is raised if the changelog anchor string cannot be found"""
+    mock_content = """# Changelog\n[PyPI History][1]\n[1]: https://pypi.org/project/google-cloud-language/#history\n
+## [1.2.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.1...google-cloud-language-v1.2.2) (2025-06-11)"""
+    expected_result = """# Changelog\n[PyPI History][1]\n[1]: https://pypi.org/project/google-cloud-language/#history\n
+## [1.2.3](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.2...google-cloud-language-v1.2.3) (2025-09-05)\n\n
+### Documentation\n
+* fix typo in BranchRule comment ([9461532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/9461532e7d19c8d71709ec3b502e5d81340fb661))\n\n
+### Features\n
+* add new UpdateRepository API ([9461532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/9461532e7d19c8d71709ec3b502e5d81340fb661))\n\n
+### Bug Fixes\n
+* some fix ([1231532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/1231532e7d19c8d71709ec3b502e5d81340fb661))
+* another fix ([1241532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/1241532e7d19c8d71709ec3b502e5d81340fb661))\n
+## [1.2.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.1...google-cloud-language-v1.2.2) (2025-06-11)"""
+    mock_changes = [
+        {
+            "type": "feat",
+            "subject": "add new UpdateRepository API",
+            "body": "This adds the ability to update a repository's properties.",
+            "piper_cl_number": "786353207",
+            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+        {
+            "type": "fix",
+            "subject": "some fix",
+            "body": "",
+            "piper_cl_number": "786353208",
+            "source_commit_hash": "1231532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+        {
+            "type": "fix",
+            "subject": "another fix",
+            "body": "",
+            "piper_cl_number": "786353209",
+            "source_commit_hash": "1241532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+        {
+            "type": "docs",
+            "subject": "fix typo in BranchRule comment",
+            "body": "",
+            "piper_cl_number": "786353210",
+            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+        },
+    ]
+    version = "1.2.3"
+    previous_version = "1.2.2"
+    package_name = "google-cloud-language"
+
+    result = _process_changelog(
+        mock_content, mock_changes, version, previous_version, package_name
+    )
+    assert result == expected_result
+
+
+def test_process_changelog_failure():
+    """Tests that value error is raised if the changelog anchor string cannot be found"""
+    with pytest.raises(ValueError):
+        _process_changelog("", [], "", "", "")
+
+
 def test_update_changelog_for_library_failure(mocker):
     m = mock_open()
 
@@ -758,6 +819,7 @@ def test_update_changelog_for_library_failure(mocker):
                 "google-cloud-language",
             )
 
+
 def test_process_version_file_success():
     version_file_contents = '__version__ = "1.2.2"'
     new_version = "1.2.3"

From 2f63be61af0580035ac384949fae441f23d359b2 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Mon, 8 Sep 2025 19:09:44 +0000
Subject: [PATCH 19/20] remove code duplication

---
 .generator/test_cli.py | 114 ++++++++++++++++-------------------------
 1 file changed, 44 insertions(+), 70 deletions(-)

diff --git a/.generator/test_cli.py b/.generator/test_cli.py
index df23fe3979dc..0f36095de0eb 100644
--- a/.generator/test_cli.py
+++ b/.generator/test_cli.py
@@ -19,6 +19,7 @@
 import subprocess
 import yaml
 import unittest.mock
+from datetime import datetime
 from unittest.mock import MagicMock, mock_open
 
 import pytest
@@ -56,6 +57,38 @@
 )
 
 
+_MOCK_LIBRARY_CHANGES = [
+    {
+        "type": "feat",
+        "subject": "add new UpdateRepository API",
+        "body": "This adds the ability to update a repository's properties.",
+        "piper_cl_number": "786353207",
+        "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+    },
+    {
+        "type": "fix",
+        "subject": "some fix",
+        "body": "",
+        "piper_cl_number": "786353208",
+        "source_commit_hash": "1231532e7d19c8d71709ec3b502e5d81340fb661",
+    },
+    {
+        "type": "fix",
+        "subject": "another fix",
+        "body": "",
+        "piper_cl_number": "786353209",
+        "source_commit_hash": "1241532e7d19c8d71709ec3b502e5d81340fb661",
+    },
+    {
+        "type": "docs",
+        "subject": "fix typo in BranchRule comment",
+        "body": "",
+        "piper_cl_number": "786353210",
+        "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
+    },
+]
+
+
 @pytest.fixture
 def mock_generate_request_file(tmp_path, monkeypatch):
     """Creates the mock request file at the correct path inside a temp dir."""
@@ -700,37 +733,25 @@ def test_update_changelog_for_library_success(mocker):
 ## [2.17.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v2.17.1...google-cloud-language-v2.17.2) (2025-06-11)
 
 """
-
-    mock_changes = [
-        {
-            "type": "feat",
-            "subject": "add new UpdateRepository API",
-            "body": "This adds the ability to update a repository's properties.",
-            "piper_cl_number": "786353207",
-            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-        {
-            "type": "docs",
-            "subject": "fix typo in BranchRule comment",
-            "body": "",
-            "piper_cl_number": "786353207",
-            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-    ]
-
     with unittest.mock.patch("cli.open", m):
         mocker.patch("cli._read_text_file", return_value=mock_content)
         _update_changelog_for_library(
-            "repo", "output", mock_changes, "1.2.3", "1.2.2", "google-cloud-language"
+            "repo",
+            "output",
+            _MOCK_LIBRARY_CHANGES,
+            "1.2.3",
+            "1.2.2",
+            "google-cloud-language",
         )
 
 
 def test_process_changelog_success():
     """Tests that value error is raised if the changelog anchor string cannot be found"""
+    current_date = datetime.now().strftime("%Y-%m-%d")
     mock_content = """# Changelog\n[PyPI History][1]\n[1]: https://pypi.org/project/google-cloud-language/#history\n
 ## [1.2.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.1...google-cloud-language-v1.2.2) (2025-06-11)"""
-    expected_result = """# Changelog\n[PyPI History][1]\n[1]: https://pypi.org/project/google-cloud-language/#history\n
-## [1.2.3](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.2...google-cloud-language-v1.2.3) (2025-09-05)\n\n
+    expected_result = f"""# Changelog\n[PyPI History][1]\n[1]: https://pypi.org/project/google-cloud-language/#history\n
+## [1.2.3](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.2...google-cloud-language-v1.2.3) ({current_date})\n\n
 ### Documentation\n
 * fix typo in BranchRule comment ([9461532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/9461532e7d19c8d71709ec3b502e5d81340fb661))\n\n
 ### Features\n
@@ -739,42 +760,12 @@ def test_process_changelog_success():
 * some fix ([1231532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/1231532e7d19c8d71709ec3b502e5d81340fb661))
 * another fix ([1241532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/1241532e7d19c8d71709ec3b502e5d81340fb661))\n
 ## [1.2.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.1...google-cloud-language-v1.2.2) (2025-06-11)"""
-    mock_changes = [
-        {
-            "type": "feat",
-            "subject": "add new UpdateRepository API",
-            "body": "This adds the ability to update a repository's properties.",
-            "piper_cl_number": "786353207",
-            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-        {
-            "type": "fix",
-            "subject": "some fix",
-            "body": "",
-            "piper_cl_number": "786353208",
-            "source_commit_hash": "1231532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-        {
-            "type": "fix",
-            "subject": "another fix",
-            "body": "",
-            "piper_cl_number": "786353209",
-            "source_commit_hash": "1241532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-        {
-            "type": "docs",
-            "subject": "fix typo in BranchRule comment",
-            "body": "",
-            "piper_cl_number": "786353210",
-            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-    ]
     version = "1.2.3"
     previous_version = "1.2.2"
     package_name = "google-cloud-language"
 
     result = _process_changelog(
-        mock_content, mock_changes, version, previous_version, package_name
+        mock_content, _MOCK_LIBRARY_CHANGES, version, previous_version, package_name
     )
     assert result == expected_result
 
@@ -790,30 +781,13 @@ def test_update_changelog_for_library_failure(mocker):
 
     mock_content = """# Changelog"""
 
-    mock_changes = [
-        {
-            "type": "feat",
-            "subject": "add new UpdateRepository API",
-            "body": "This adds the ability to update a repository's properties.",
-            "piper_cl_number": "786353207",
-            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-        {
-            "type": "docs",
-            "subject": "fix typo in BranchRule comment",
-            "body": "",
-            "piper_cl_number": "786353207",
-            "source_commit_hash": "9461532e7d19c8d71709ec3b502e5d81340fb661",
-        },
-    ]
-
     with pytest.raises(ValueError):
         with unittest.mock.patch("cli.open", m):
             mocker.patch("cli._read_text_file", return_value=mock_content)
             _update_changelog_for_library(
                 "repo",
                 "output",
-                mock_changes,
+                _MOCK_LIBRARY_CHANGES,
                 "1.2.3",
                 "1.2.2",
                 "google-cloud-language",

From 4973613d71c30d0b8498bec45f1485edf179b3c5 Mon Sep 17 00:00:00 2001
From: Anthonios Partheniou <partheniou@google.com>
Date: Mon, 8 Sep 2025 19:11:50 +0000
Subject: [PATCH 20/20] refactor

---
 .generator/cli.py | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/.generator/cli.py b/.generator/cli.py
index 8c86c4831433..df843c165a7c 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -649,15 +649,13 @@ def _process_changelog(
     for change_type, changes in grouped_changes:
         # We only care about feat, fix, docs
         adjusted_change_type = change_type.replace("!", "")
+        change_type_map = {
+            "feat": "Features",
+            "fix": "Bug Fixes",
+            "docs": "Documentation",
+        }
         if adjusted_change_type in ["feat", "fix", "docs"]:
-            if adjusted_change_type == "feat":
-                adjusted_change_type = "Features"
-            elif adjusted_change_type == "fix":
-                adjusted_change_type = "Bug Fixes"
-            else:
-                adjusted_change_type = "Documentation"
-
-            entry_parts.append(f"\n\n### {adjusted_change_type}\n")
+            entry_parts.append(f"\n\n### {change_type_map[adjusted_change_type]}\n")
             for change in changes:
                 commit_link = f"([{change['source_commit_hash']}]({repo_url}/commit/{change['source_commit_hash']}))"
                 entry_parts.append(f"* {change['subject']} {commit_link}")