Route requests exclusively to free-tier models, spending no DA balance.
Not yet available.
The Free Models Router routes every request to the best available free-tier model for the detected task — no DA balance required. It is the zero-cost entry point to the OpenDunes catalog, suitable for prototyping, low-stakes workloads, and developers evaluating the API before depositing credits.
Set model to "opendunes/free":
The response model field tells you which free model handled the request. Zero DA is deducted.
The Free Models Router draws from the same pool as the :free variant — models where at least one provider offers free-tier capacity. Among eligible models, it ranks candidates by:
If no free model is currently available, the request fails with 404 no_provider rather than falling back to a paid model.
Free-tier capacity is shared infrastructure and carries constraints:
| Constraint | Value |
|---|---|
| Rate limit | 20 requests/minute per key (lower than paid) |
| Max output tokens | 4,096 per request |
| Streaming | Supported |
| Tool calling | Not available on free tier |
| Priority | Lower — expect higher latency during peak hours |
For production workloads that need reliability, add DA credits and use the Auto Router or a specific model slug.
Browse all free-eligible models:
Or visit /models?free=true in the dashboard.
| Scenario | Recommended |
|---|---|
| Exploring the API for the first time | Yes |
| Prototyping a new feature | Yes |
| Production with SLA requirements | No — use paid models |
| High-volume batch jobs | No — rate limits are too restrictive |
| Demos and hackathons | Yes |
You can use the Free Models Router as the last entry in a model fallbacks list — try a premium model first, fall back to free if it fails:
This pattern gives you the best available paid model with a free fallback for resilience.
Zero. Requests routed through opendunes/free cost nothing. The X-Balance-Available header in the response is unchanged.