Claude 4 Down? Fix It in 60 Seconds — Change One Line

Published June 15, 2026 · 3 min read · Updated in real-time

If your Claude 4 API calls just started failing, you're not alone. Thousands of developers woke up today to HTTP 410 errors, "model not found" messages, and broken applications. Claude 4 Opus and Claude 4 Sonnet were permanently retired on June 15, 2026.

The good news? You can fix this in 60 seconds by changing one line of code. And while you're at it, you'll save 67-97% on your API costs.

Code Fixes by Language

# Before (broken)
import anthropic
client = anthropic.Anthropic()
response = client.messages.create(
    model="claude-4-opus",
    messages=[{"role": "user", "content": "Hello"}]
)

# After (fixed) — only the model name changes
response = client.messages.create(
    model="claude-opus-4-8",
    messages=[{"role": "user", "content": "Hello"}]
)

// Before (broken)
import Anthropic from '@anthropic-ai/sdk';
const client = new Anthropic();
const response = await client.messages.create({
  model: "claude-4-opus",
  messages: [{ role: "user", content: "Hello" }]
});

// After (fixed) — only the model name changes
const response = await client.messages.create({
  model: "claude-opus-4-8",
  messages: [{ role: "user", content: "Hello" }]
});

# Before (broken)
curl https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -d '"model": "claude-4-opus"'

# After (fixed)
curl https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -d '"model": "claude-opus-4-8"'

// Before (broken)
import Anthropic from '@anthropic-ai/sdk';
const client = new Anthropic();

const message = await client.messages.create({
  model: "claude-4-opus",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Hello" }]
});

// After (fixed)
const message = await client.messages.create({
  model: "claude-opus-4-8",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Hello" }]
});

You're About to Save a Lot of Money

Here's the thing — Claude 4 Opus was expensive. $15 per million input tokens, $75 per million output tokens. The new alternatives are dramatically cheaper:

That's $2,400+/year in savings just by switching models. And the fix takes 60 seconds.

What About My API Keys and Data?

Your existing Anthropic API key still works with the new models. You don't need to:

• Generate a new API key
• Update your SDK version
• Change your authentication code
• Migrate your data or conversation history

You only need to change the model name string. Everything else stays the same.

Error Messages You Might Be Seeing

Depending on how your code handles errors, you might see one of these:

• HTTP 410 Gone — The model endpoint no longer exists
• "model_not_found" — The model ID isn't recognized
• "invalid_model_error" — You're using a deprecated model name
• "claude-4-opus has been deprecated" — Direct deprecation message

All of these have the same fix: change the model name.

Claude 4 → New Model Mapping

Looking to Switch Providers Entirely?

If you want to explore alternatives beyond Anthropic, here are the best options across providers:

• OpenAI GPT-5 — $1.25/$10 per 1M tokens. Great for general tasks.
• Google Gemini 3.1 Pro — $2/$12 per 1M tokens. 1M context window.
• DeepSeek V4 Pro — $0.435/$0.87 per 1M tokens. Budget king.
• Mistral Large — $2/$6 per 1M tokens. Strong European option.

Use our side-by-side comparison tool to see all 42 models compared.

Related Resources

• Claude 4 API Status — Live Checker
• Claude 4 Migration Cost Calculator
• Claude 4 Migration Hub — Complete Guide
• Claude 4 Alternatives by Use Case
• Claude 4 Shutdown Complete — What Happened
• Claude 4 Is Dead — What to Do Now
• Claude 4 Is Gone — Now What?
• Claude 4 Retired — Here's What to Do
• AI API Cost Calculator — Compare All Models