OpenRouter for Bolna Voice Agents

OpenRouter is a unified API gateway that lets you access models from multiple providers — OpenAI, Anthropic, Google, Mistral, Meta, and others — through a single integration. Use it when you want to avoid managing multiple API keys, need automatic fallback between providers, or want to experiment with models without separate provider accounts.

Quick config

"llm_agent": {
  "agent_type": "simple_llm_agent",
  "agent_flow_type": "streaming",
  "llm_config": {
    "provider": "openrouter",
    "model": "openai/gpt-4o-mini",
    "max_tokens": 150,
    "temperature": 0.2
  }
}

Connect your OpenRouter account at platform.bolna.ai/auth/openrouter. Get your API key at openrouter.ai.

Recommended models for voice

OpenRouter uses provider/model-name slugs. These are the top picks for voice agents:

Model slug	Context	Best for
`openai/gpt-4o-mini`	128K	Best OpenAI balance via OpenRouter
`openai/gpt-4o`	128K	Higher quality OpenAI via OpenRouter
`anthropic/claude-haiku-4.5`	200K	Fast, cost-efficient Claude
`anthropic/claude-sonnet-4.1`	200K	High-quality Claude
`google/gemini-3-flash`	1M	Fast Gemini, good multilingual
`google/gemini-3-flash-lite`	1M	Cheapest large-context option
`mistralai/mistral-small`	32K	Fast, low-cost European option
`meta-llama/llama-3.1-70b`	128K	Open-weight; cost-effective
`deepseek/deepseek-chat`	1M	Ultra-low cost (DeepSeek V4)

For the full model catalog, see openrouter.ai/models.

Key settings

Setting	Type	Recommended	Description
`provider`	string	`"openrouter"`	Provider name
`model`	string	e.g. `"openai/gpt-4o-mini"`	Full OpenRouter model slug
`max_tokens`	integer	`150`	Cap on response length — keep short for voice
`temperature`	float	`0.2`	Lower = more consistent
`agent_flow_type`	string	`"streaming"`	Always `"streaming"` for voice

When to use OpenRouter vs direct providers

Use OpenRouter when:

You want one API key for multiple providers
You need automatic fallback if a provider is down
You’re testing and comparing models quickly
You don’t have existing API relationships with providers

Use direct provider integrations when:

You need the absolute latest model versions (OpenRouter has a short lag)
Your compliance requires knowing exactly which provider handles your data
You want provider-specific features (Azure data residency, Anthropic Workspaces, etc.)

FAQ

Does OpenRouter add latency?

Minimal — typically a few milliseconds for routing. For most voice agents this is negligible. If you’re highly latency-sensitive, benchmark against a direct provider connection.

Which OpenRouter model is best for Hindi or Indian languages?

google/gemini-3-flash has strong multilingual capability including Indian languages. For the best Indian language support, consider using Sarvam directly as the LLM provider.

Can I set fallback models on OpenRouter?

Yes — OpenRouter supports model routing and fallback configuration through their dashboard. Set your primary model in Bolna and configure fallback logic in the OpenRouter console.

LLM Tab — configure LLM in the dashboard
OpenAI — direct OpenAI integration
Anthropic — direct Anthropic integration
Google Gemini — direct Gemini integration
Prompting Guide — write effective prompts for voice

Overview & Evaluation

Concepts

Build & Configure Agents

Voice & Knowledge

Integrations

Multilingual Voice Agents

Advanced Capabilities

Graph Agents

Enterprise & Security

Pricing

OpenRouter for Bolna Voice Agents

Quick config

Recommended models for voice

Key settings

When to use OpenRouter vs direct providers

FAQ

​Quick config

​Recommended models for voice

​Key settings

​When to use OpenRouter vs direct providers

​FAQ

​Related

Quick config

Recommended models for voice

Key settings

When to use OpenRouter vs direct providers

FAQ

Related