Ops Alert: Claude Opus 4.1 API Retires This Tuesday — One-Line Fix Before Your Calls Error Out

Claude Opus 4.1 (claude-opus-4-1-20250805) hits hard API end-of-life on August 5 — two days away — and any route still sending requests to that model ID will get errors starting Tuesday.

The fix is a one-string change:

# Before
model = "claude-opus-4-1-20250805"

# After
model = "claude-opus-4-8"

Claude Opus 4.8 is backward-compatible: same API interface, same parameters, same prompt format. Check env vars, config files, and hardcoded model strings across your codebase — the migration typically takes under an hour including testing.

Also in the queue: OpenAI refreshed GPT-5.5 Instant with style and quality improvements and removed Canvas in favor of in-chat code and writing blocks. And o3 retires from ChatGPT on August 26 — start moving any eval suites or benchmarks that depend on o3 to o4-mini or GPT-5 now before the sunset.

Why it matters: August 5 is a hard cut-off — requests to the retired endpoint return errors, not degraded responses. "It worked yesterday" will turn into a broken CI run or a failed production deploy overnight. A one-line fix in dev takes minutes; diagnosing an unexpected API error in prod takes much longer.

Sources: Claude Platform Release Notes, Opus 4.1 Migration Guide — TheRouter.ai, OpenAI Model Release Notes