Free tier

17Free tier

Some of the cheapest models can be called at no cost by adding :free to the model id. A free request bills $0, works with a zero balance, and goes through the same routing, streaming and logging as everything else. Models that support it carry "variants": ["free"] in GET /models; using :free on any other model returns 400.

curl https://rapidrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $RAPIDROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-oss-120b:free",
    "messages": [{ "role": "user", "content": "Hi" }]
  }'

# usage.cost is 0. No credits are debited.

Limits are per account, per UTC day: 50 free requests a day, raised to 1,000 once your lifetime paid usage reaches $10. Going over returns 429 with code free_tier_exhausted; the counter resets at midnight UTC. Rate limits and the concurrency ceiling still apply.

Separately, the models whose catalog id already ends in :free (the ones tagged Free on the models page) are sponsored: we pay the provider for them out of a shared daily pool that resets daily at 18:30 UTC, and they do not count against the per-account quota above. When the pool for the day is spent they return 429 with code free_pool_exhausted until it refills.