Claude 3 Opus — Deprecated

Quick fix — copy & paste

Choose your language. The "before" block matches the deprecated call; the "after" block is the drop-in replacement.

# Vertex AI: Claude 3 Opus (deprecated)
model = "Claude 3 Opus"

# No direct replacement — see Vertex AI docs.
# Pick a current model from the provider's available list.

// Vertex AI: Claude 3 Opus (deprecated)
const model = "Claude 3 Opus";

// No direct replacement — see Vertex AI docs.
const model = "<choose a current model>";

"model": "Claude 3 Opus"

"model": "<choose a current model>"

This migration was generated automatically from the model rename. If your code does more than swap a model id, double-check request/response shapes against the official Vertex AI migration guide.

Error messages

Seeing one of these? You're in the right place.

• model_not_found: Claude 3 Opus
• The model `Claude 3 Opus` has been deprecated
• The model `Claude 3 Opus` does not exist or you do not have access to it

Other Vertex AI deprecations

• Claude 3.7 Sonnet 2026-05-11 · 3d
• Claude 3.5 Haiku 2026-07-05 · 58d
• Anthropic's Claude 3 Haiku 2026-08-23 · 107d

What this means for your code

Claude 3 Opus is a general-purpose chat model used through the standard messages or chat completions endpoint. Most production traffic on chat models comes from streaming responses, function calling, and tool use. After the shutdown date, every API call returns an error and your app breaks for end users until the model id is updated.

Vertex AI has scheduled Claude 3 Opus for shutdown on 2026-08-01. That gives you 85 days to migrate. Until then the model still works, but every API call after that date will return a model_not_found error.

Find every call in your codebase

Before you change anything, locate every place the deprecated model id is referenced. Search source files, environment files, feature flags, and config repos. Use these commands from your project root:

grep -rn '"Claude 3 Opus"' --include="*.py" .

grep -rn '"Claude 3 Opus"' --include="*.{js,ts,tsx,jsx}" .

grep -rn "Claude 3 Opus" .

Migration checklist

Steps in order. Skip any that don't apply, but read the whole list — for chat models, the non-obvious steps are usually the ones that break in production.

1. 1. Search for the deprecated model id in your application code, environment variables, and feature flags
2. 2. Update the model id in your API client configuration
3. 3. Re-run integration tests that exercise streaming, function calling, and structured outputs
4. 4. If you use prompt caching, verify the new model supports the same cache scopes
5. 5. Compare token costs on a representative sample of prompts before deploying