Catching Deprecated Gemini Models in CI ― A Guard for Back-to-Back Shutdown Deadlines

#!/usr/bin/env python3
"""Detect deprecated Gemini model strings in a repository.
Switches between warning (informational) and error (fails CI)
based on the days remaining until shutdown."""
 
import json
import os
import re
import sys
from datetime import date, datetime
 
# Treat as error (fail CI) once remaining days drop to or below this
FAIL_WITHIN_DAYS = 30
# Extensions to scan
SCAN_EXT = {".py", ".ts", ".tsx", ".js", ".jsx", ".mjs", ".json", ".yaml", ".yml", ".md", ".mdx", ".env", ".sh"}
# Directories to skip
SKIP_DIRS = {".git", "node_modules", ".next", "dist", "build", "vendor", ".venv"}
 
 
def load_registry(path):
    with open(path, encoding="utf-8") as f:
        data = json.load(f)
    items = []
    for d in data["deprecations"]:
        shutdown = datetime.strptime(d["shutdown"], "%Y-%m-%d").date()
        # Bound by non-word characters so 'gemini-2.0-flash' does not
        # falsely match 'gemini-2.0-flash-lite'
        pattern = re.compile(r"(?<![\w.-])" + re.escape(d["model"]) + r"(?![\w-])")
        items.append({**d, "shutdown_date": shutdown, "pattern": pattern})
    return items
 
 
def iter_files(root):
    for dirpath, dirnames, filenames in os.walk(root):
        dirnames[:] = [d for d in dirnames if d not in SKIP_DIRS]
        for name in filenames:
            ext = os.path.splitext(name)[1].lower()
            if ext in SCAN_EXT or name.startswith(".env"):
                yield os.path.join(dirpath, name)
 
 
def scan(root, registry, today):
    hits = []
    for path in iter_files(root):
        try:
            with open(path, encoding="utf-8", errors="ignore") as f:
                lines = f.readlines()
        except OSError:
            continue
        for lineno, line in enumerate(lines, 1):
            for item in registry:
                if item["pattern"].search(line):
                    remaining = (item["shutdown_date"] - today).days
                    hits.append({
                        "path": os.path.relpath(path, root),
                        "line": lineno,
                        "model": item["model"],
                        "replacement": item["replacement"],
                        "remaining": remaining,
                        "text": line.strip()[:120],
                    })
    return hits
 
 
def main():
    registry_path = os.environ.get("DEPRECATION_REGISTRY", "deprecations.json")
    root = sys.argv[1] if len(sys.argv) > 1 else "."
    today = date.today()
 
    registry = load_registry(registry_path)
    hits = scan(root, registry, today)
 
    if not hits:
        print("OK: no deprecated model strings found.")
        return 0
 
    # Sort by fewest days remaining first
    hits.sort(key=lambda h: h["remaining"])
    has_error = False
    for h in hits:
        level = "ERROR" if h["remaining"] <= FAIL_WITHIN_DAYS else "WARN"
        if level == "ERROR":
            has_error = True
        when = f"{h['remaining']}d left" if h["remaining"] >= 0 else f"{abs(h['remaining'])}d overdue"
        print(f"[{level}] {h['path']}:{h['line']} "
              f"{h['model']} -> {h['replacement']} ({when})")
        print(f"        {h['text']}")
 
    print(f"\n{len(hits)} hit(s) / error threshold within {FAIL_WITHIN_DAYS} days")
    return 1 if has_error else 0
 
 
if __name__ == "__main__":
    sys.exit(main())

[ERROR] scripts/make_thumbnail.py:42 gemini-3.1-flash-image-preview -> gemini-3.1-flash-image (8d left)
        model="gemini-3.1-flash-image-preview",
[WARN] docs/sample.md:88 gemini-2.0-flash -> gemini-3.5-flash (105d left)
        response = client.generate(model="gemini-2.0-flash", ...)
 
2 hit(s) / error threshold within 30 days

# before: preceding char is none of \w . - / after: following char is none of \w -
pattern = re.compile(r"(?<![\w.-])" + re.escape(d["model"]) + r"(?![\w-])")

name: gemini-deprecation-guard
on: [push, pull_request]
 
jobs:
  guard:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - name: Detect deprecated models
        env:
          DEPRECATION_REGISTRY: ci/deprecations.json
        run: python ci/check_deprecated_models.py .

# .pre-commit-config.yaml
- repo: local
  hooks:
    - id: gemini-deprecation-guard
      name: Gemini deprecated-model guard
      entry: python ci/check_deprecated_models.py
      language: system
      pass_filenames: false

import os
from google import genai
 
client = genai.Client(api_key=os.environ["YOUR_GEMINI_API_KEY"])
 
# Fetch the model list the API returns and pick up ones whose
# description hints at deprecation
for m in client.models.list():
    name = m.name.split("/")[-1]
    desc = (getattr(m, "description", "") or "").lower()
    if "deprecat" in desc or "preview" in name:
        print(f"check: {name} ― {desc[:80]}")