OpenRouter returned a model not found error:

Error: Model not found: anthropic/claude-3-opus

Here is how to fix it.

Fix 1: Check model name

OpenRouter uses specific naming:

# Wrong
model = "claude-3-opus"

# Correct
model = "anthropic/claude-3-opus"

Fix 2: List available models

# Get all models
curl https://openrouter.ai/api/v1/models \
  -H "Authorization: Bearer $OPENROUTER_API_KEY"

# Or search
curl "https://openrouter.ai/api/v1/models?q=claude" \
  -H "Authorization: Bearer $OPENROUTER_API_KEY"

Fix 3: Check model availability

Some models are temporary or limited:

# Check if model exists
response = client.models.list()
models = [m.id for m in response.data]
print(f"Available: {models}")

Fix 4: Use alternative model

If your model is not available:

Original	Alternative
claude-3-opus	anthropic/claude-3-opus
gpt-4-turbo	openai/gpt-4-turbo
gemini-pro	google/gemini-pro

Fix 5: Check model variants

Some models have multiple versions:

# Model with provider prefix
model = "anthropic/claude-3-opus"

# Model without prefix (may not work)
model = "claude-3-opus"

# Model with version
model = "anthropic/claude-3-opus-20240229"

Fix 6: Use free models

Free models are always available:

# Free models
model = "meta-llama/llama-3-8b:free"
model = "mistralai/mistral-7b:free"

Still not working?

1. Check OpenRouter status — status.openrouter.ai
2. Try different provider — Model may be temporarily down
3. Use direct API — Anthropic/OpenAI directly
4. Check billing — Some models require credits

FAQ

Why does OpenRouter say “model not found”?

The most common cause is using the wrong model name. OpenRouter requires the provider prefix (e.g., anthropic/claude-3-opus). Run curl https://openrouter.ai/api/v1/models to see all available models.

How do I find available models?

Use the API: curl https://openrouter.ai/api/v1/models -H "Authorization: Bearer $KEY". Or visit openrouter.ai/models to browse all available models with pricing.

Are free models always available?

Free models (with :free suffix) are generally available but have lower rate limits. They may be temporarily unavailable during high traffic periods. Try a paid model if free ones are down.

Related: OpenRouter Complete Guide · OpenRouter Rate Limit Fix · AI API Pricing Compared 2026 · Best Free AI APIs 2026