Re_Backend/CLAUDE_MODELS.md

Claude Model Versions - Quick Reference

✅ Current Claude Model (November 2025)

Claude 4 Models (Latest)

• claude-sonnet-4-20250514 ← DEFAULT & CURRENT
  • Latest Claude Sonnet 4 model
  • Released: May 14, 2025
  • Best for complex reasoning and conclusion generation
  • This is what your API key supports

⚠️ Deprecated Models (Do NOT Use)

The following Claude 3 models are deprecated and no longer available:

• ❌ claude-3-opus-20240229 - Deprecated
• ❌ claude-3-sonnet-20240229 - Deprecated
• ❌ claude-3-haiku-20240307 - Deprecated
• ❌ claude-3-5-sonnet-20240620 - Deprecated

These will return 404 errors.

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🎯 What Happened?

All Claude 3 and 3.5 models have been deprecated and replaced with Claude 4.

Your API key is current and working perfectly - it just needs the current model version.

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🔧 How to Change the Model

Option 1: Environment Variable (Recommended)

Add to your .env file:

# Use Claude Sonnet 4 (current default)
CLAUDE_MODEL=claude-sonnet-4-20250514

# This is the ONLY model that currently works

Option 2: Admin Configuration (Future)

The model can also be configured via the admin panel under AI settings.

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🐛 Troubleshooting 404 Errors

If you get a 404 error like:

model: claude-3-5-sonnet-20241029
{"type":"error","error":{"type":"not_found_error","message":"model: ..."}

Solutions:

1. Check your .env file for CLAUDE_MODEL variable
2. Remove or update any invalid model version
3. Restart the backend server after changing .env
4. Check server logs on startup to see which model is being used:

   [AI Service] ✅ Claude provider initialized with model: claude-3-5-sonnet-20240620
   

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📊 Current Default

The system now defaults to:

claude-sonnet-4-20250514

This is the current Claude 4 model (November 2025) and the only one that works with active API keys.

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🔑 API Key Requirements

Make sure you have a valid Anthropic API key in your .env:

CLAUDE_API_KEY=sk-ant-api03-...
# OR
ANTHROPIC_API_KEY=sk-ant-api03-...

Get your API key from: https://console.anthropic.com/

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📝 Model Selection Guide

Use Case	Recommended Model	Notes
All use cases	claude-sonnet-4-20250514	Only model currently available
Older models	❌ Deprecated	Will return 404 errors

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🎯 Quick Fix for 404 Errors

If you're getting 404 errors (model not found):

Your API key likely doesn't have access to Claude 3.5 models.

Solution: Use Claude 3 Opus (works with all API keys)

1. Restart backend - the default is now Claude 3 Opus:

   npm run dev
   

2. Check logs for confirmation:

   [AI Service] ✅ Claude provider initialized with model: claude-3-opus-20240229
   

3. Test again - Should work now! ✅

Alternative: Try Other Models

If Opus doesn't work, try in your .env:

# Try Sonnet (lighter, faster)
CLAUDE_MODEL=claude-3-sonnet-20240229

# OR try Haiku (fastest)
CLAUDE_MODEL=claude-3-haiku-20240307

Then restart backend.