OpenRouter

OpenRouter is a unified API that provides access to 200+ models from OpenAI, Anthropic, Meta, Mistral, Google, and more — with automatic fallback and load balancing.

Install

pip install synapsekit[openai]

OpenRouter uses the OpenAI-compatible API, so it requires the openai package.

Usage

from synapsekit import LLMConfig
from synapsekit.llm.openrouter import OpenRouterLLM

llm = OpenRouterLLM(LLMConfig(
    model="openai/gpt-4o",
    api_key="sk-or-...",
))

async for token in llm.stream("What is RAG?"):
    print(token, end="", flush=True)

Available models

OpenRouter supports 200+ models. Some popular ones:

Model	ID
GPT-4o	openai/gpt-4o
Claude 3.5 Sonnet	anthropic/claude-3.5-sonnet
Llama 3.3 70B	meta-llama/llama-3.3-70b-instruct
Mixtral 8x7B	mistralai/mixtral-8x7b-instruct
Gemini Pro	google/gemini-pro

See the full list at openrouter.ai/models.

Function calling

result = await llm.call_with_tools(messages, tools)

Function calling support depends on the underlying model.

Auto-detection

Models with a / in the name are auto-detected as OpenRouter:

from synapsekit import RAG

rag = RAG(model="openai/gpt-4o", api_key="sk-or-...")

Custom base URL

llm = OpenRouterLLM(config, base_url="http://localhost:8000/v1")

Parameters

Parameter	Description
model	Any model ID from OpenRouter (e.g. openai/gpt-4o)
api_key	Your OpenRouter API key
base_url	Custom API base URL (default: https://openrouter.ai/api/v1)