Free Models (:free)

FastRouter exposes select models at no charge via the :free slug — up to 10 requests per org per day, with no payment required.

Introduction

This feature is available to all orgs regardless of billing status. Provided at FastRouter's discretion; free access on any given model can be paused or removed at any time.

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How It Works

Append :free to any supported model ID:

sarvam/sarvam-105b:free

FastRouter strips the suffix, checks whether :free is enabled for that model, verifies your org's daily quota, then routes the request normally. The :free suffix is invisible to the downstream provider.

If a model does not have :free enabled, the request is rejected. The standard model ID (without the suffix) is unaffected.

Note: The 10-request daily quota is org-wide and shared across all API keys and members. Paid orgs using :free consume from this free quota — not from billing credits.

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Supported Models

Currently, supported on Sarvam models in our catalog for a limited time.

Model	Free Model ID
Sarvam: Sarvam 105B	sarvam/sarvam-105b:free
Sarvam: Sarvam 30B	sarvam/sarvam-30b:free
Sarvam: Saaras V3	sarvam/saaras:v3:free
Sarvam: Bulbul V2	sarvam/bulbul:v2:free

:free is enabled on a per-model basis. Check the model catalog — eligible models display a Free badge on their detail page.

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Usage

cURL

curl 'https://api.fastrouter.ai/api/v1/chat/completions' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "sarvam/sarvam-105b:free",
    "messages": [
      { "role": "user", "content": "Explain backpressure in streaming systems." }
    ]
  }'

Python (OpenAI SDK)

from openai import OpenAI

client = OpenAI(
    base_url="https://api.fastrouter.ai/api/v1",
    api_key="YOUR_API_KEY",
)

response = client.chat.completions.create(
    model="sarvam/sarvam-105b:free",
    messages=[
        {"role": "user", "content": "Explain backpressure in streaming systems."}
    ],
)

print(response.choices[0].message.content)

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Quota & Limits

Property	Value
Requests per org per day	10
Scope	Per model — quota tracked independently per model_id
Reset	Daily at UTC midnight
Carry-over	None — unused requests do not roll over
Paid org behaviour	Consumes free quota, not billing credits

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Error Responses

:free not enabled on this model — 400

Returned when :free is used on a model that does not have the slug enabled.

{
  "error": {
    "code": "free_slug_not_enabled",
    "message": "The :free slug is not available for this model. Use the standard model ID or check the model catalog for supported free models.",
    "type": "invalid_request_error"
  }
}

Daily quota exhausted — 429

Returned when your org has used all 10 free requests for the day on this model. The response includes a Retry-After header pointing to the next UTC midnight reset.

{
  "error": {
    "code": "free_quota_exceeded",
    "message": "Your organisation has reached the daily free request limit for this model.",
    "type": "rate_limit_error",
    "quota_limit": 10,
    "quota_used": 10,
    "reset_at": "2026-05-30T00:00:00Z"
  }
}

To continue without waiting for the reset, remove the :free suffix to route as a standard paid request.

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Activity Log

All :free requests appear in your Activity Log tagged with a Free tier indicator. Cost is recorded as $0.00. Usage analytics include free-tier traffic separately so it does not skew your paid consumption metrics.

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FAQ

Does :free support all API parameters? Yes — structured outputs, tool use, streaming, and all parameters supported by the underlying model work with :free.

Can I combine :free with :flex? No. :free and :flex are mutually exclusive suffixes.

Is the 10-request limit shared across all free models, or per model? Per model. Each model has its own independent quota counter, so using sarvam/sarvam-105b:free does not consume quota for any other :free model.

What happens to a request if :free access is removed from a model? It returns a 400 error, the same as using :free on a model that never had it enabled. The standard model ID continues to work normally.