> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aion.to/llms.txt
> Use this file to discover all available pages before exploring further.

# Model Service

> Google ADK LiteLlm model configured for Aion.

Aion provides a helper function to create a Google ADK `LiteLlm` model instance
that is automatically configured for use within the Aion framework.

The helper handles authentication and bearer token refresh transparently, so
you can focus on your agent logic.

## Import

```python theme={null}
from aion.adk.authoring import aion_lite_llm
```

## Overview

```python theme={null}
from google.adk.agent import Agent

from aion.adk.authoring import aion_lite_llm

agent = Agent(
    name="my_agent",
    model=aion_lite_llm("model-id-from-control-plane"),
)
```

The model ID is the identifier from the Aion control-plane model catalog, not
a raw provider model name.

## `aion_lite_llm(...)`

```python theme={null}
aion_lite_llm(
    model: str,
    **kwargs: Any,
) -> LiteLlm
```

Create a Google ADK `LiteLlm` instance configured for Aion.

Aion resolves the bearer token and principal selector headers on every
completion call, so the model always uses fresh credentials without any extra
setup in your agent code.

**Parameters:**

| Parameter  | Type  | Description                                               |
| ---------- | ----- | --------------------------------------------------------- |
| `model`    | `str` | Model ID from the Aion control plane model catalog        |
| `**kwargs` | `Any` | Additional keyword arguments forwarded to ADK's `LiteLlm` |

**Returns:**

A Google ADK `LiteLlm` instance backed by Aion's model proxy.

**Raises:**

* `ImportError` — If `google-adk` with `LiteLlm` support is not installed

**Example:**

```python theme={null}
from google.adk.agent import Agent

from aion.adk.authoring import aion_lite_llm

agent = Agent(
    name="research_agent",
    model=aion_lite_llm("model-id-from-control-plane"),
    instruction="You are a helpful research assistant.",
)
```

## Usage with MCP Tools

`aion_lite_llm` is typically paired with `aion_adk_mcp_toolset` when the agent
needs tools from Aion's control plane:

```python theme={null}
from google.adk.agent import Agent

from aion.adk.authoring import aion_adk_mcp_toolset, aion_lite_llm
from aion.api import CapabilityReference, CapabilitySubjectSource, RuntimeCapabilityReference

agent = Agent(
    name="support_agent",
    model=aion_lite_llm("model-id-from-control-plane"),
    tools=[
        aion_adk_mcp_toolset(
            capability_references=[
                CapabilityReference.global_mcp(),
            ],
            runtime_capability_references=[
                RuntimeCapabilityReference.primary_mcp(
                    CapabilitySubjectSource.INCOMING_DISTRIBUTION
                ),
            ],
        )
    ],
)
```

## Related Pages

* [Google ADK MCP Guide](/sdk/google-adk/guides/mcp)
* [Google ADK MCP API](/sdk/google-adk/api/mcp)
* [Thread](/sdk/google-adk/api/thread)