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

# Types

> Documentation for the core types used in the Agent User Interaction Protocol Python SDK

# Core Types

The Agent User Interaction Protocol Python SDK is built on a set of core types
that represent the fundamental structures used throughout the system. This page
documents these types and their properties.

## RunAgentInput

`from ag_ui.core import RunAgentInput`

Input parameters for running an agent. In the HTTP API, this is the body of the
`POST` request.

```python theme={null}
class RunAgentInput(ConfiguredBaseModel):
    thread_id: str
    run_id: str
    state: Any
    messages: List[Message]
    tools: List[Tool]
    context: List[Context]
    forwarded_props: Any
```

| Property | Type | Description |
| - | - | - |
| `thread_id` | `str` | ID of the conversation thread |
| `run_id` | `str` | ID of the current run |
| `state` | `Any` | Current state of the agent |
| `messages` | `List[Message]` | List of messages in the conversation |
| `tools` | `List[Tool]` | List of tools available to the agent |
| `context` | `List[Context]` | List of context objects provided to the agent |
| `forwarded_props` | `Any` | Additional properties forwarded to the agent |

## Message Types

The SDK includes several message types that represent different kinds of
messages in the system.

### Role

`from ag_ui.core import Role`

Represents the possible roles a message sender can have.

```python theme={null}
Role = Literal["developer", "system", "assistant", "user", "tool"]
```

### DeveloperMessage

`from ag_ui.core import DeveloperMessage`

Represents a message from a developer.

```python theme={null}
class DeveloperMessage(BaseMessage):
    role: Literal["developer"]
    content: str
```

| Property | Type | Description |
| - | - | - |
| `id` | `str` | Unique identifier for the message |
| `role` | `Literal["developer"]` | Role of the message sender, fixed as "developer" |
| `content` | `str` | Text content of the message (required) |
| `name` | `Optional[str]` | Optional name of the sender |

### SystemMessage

`from ag_ui.core import SystemMessage`

Represents a system message.

```python theme={null}
class SystemMessage(BaseMessage):
    role: Literal["system"]
    content: str
```

| Property | Type | Description |
| - | - | - |
| `id` | `str` | Unique identifier for the message |
| `role` | `Literal["system"]` | Role of the message sender, fixed as "system" |
| `content` | `str` | Text content of the message (required) |
| `name` | `Optional[str]` | Optional name of the sender |

### AssistantMessage

`from ag_ui.core import AssistantMessage`

Represents a message from an assistant.

```python theme={null}
class AssistantMessage(BaseMessage):
    role: Literal["assistant"]
    content: Optional[str] = None
    tool_calls: Optional[List[ToolCall]] = None
```

| Property | Type | Description |
| - | - | - |
| `id` | `str` | Unique identifier for the message |
| `role` | `Literal["assistant"]` | Role of the message sender, fixed as "assistant" |
| `content` | `Optional[str]` | Text content of the message |
| `name` | `Optional[str]` | Name of the sender |
| `tool_calls` | `Optional[List[ToolCall]]` | Tool calls made in this message |

### UserMessage

`from ag_ui.core import UserMessage`

Represents a message from a user.

```python theme={null}
class UserMessage(BaseMessage):
    role: Literal["user"]
    content: str
```

| Property | Type | Description |
| - | - | - |
| `id` | `str` | Unique identifier for the message |
| `role` | `Literal["user"]` | Role of the message sender, fixed as "user" |
| `content` | `str` | Text content of the message (required) |
| `name` | `Optional[str]` | Optional name of the sender |

### ToolMessage

`from ag_ui.core import ToolMessage`

Represents a message from a tool.

```python theme={null}
class ToolMessage(ConfiguredBaseModel):
    id: str
    role: Literal["tool"]
    content: str
    tool_call_id: str
```

| Property | Type | Description |
| - | - | - |
| `id` | `str` | Unique identifier for the message |
| `content` | `str` | Text content of the message |
| `role` | `Literal["tool"]` | Role of the message sender, fixed as "tool" |
| `tool_call_id` | `str` | ID of the tool call this message responds to |

### Message

`from ag_ui.core import Message`

A union type representing any type of message in the system.

```python theme={null}
Message = Annotated[
    Union[DeveloperMessage, SystemMessage, AssistantMessage, UserMessage, ToolMessage],
    Field(discriminator="role")
]
```

### ToolCall

`from ag_ui.core import ToolCall`

Represents a tool call made by an agent.

```python theme={null}
class ToolCall(ConfiguredBaseModel):
    id: str
    type: Literal["function"]
    function: FunctionCall
```

| Property | Type | Description |
| - | - | - |
| `id` | `str` | Unique identifier for the tool call |
| `type` | `Literal["function"]` | Type of the tool call, always "function" |
| `function` | `FunctionCall` | Details about the function being called |

#### FunctionCall

`from ag_ui.core import FunctionCall`

Represents function name and arguments in a tool call.

```python theme={null}
class FunctionCall(ConfiguredBaseModel):
    name: str
    arguments: str
```

| Property | Type | Description |
| - | - | - |
| `name` | `str` | Name of the function to call |
| `arguments` | `str` | JSON-encoded string of arguments to the function |

## Context

`from ag_ui.core import Context`

Represents a piece of contextual information provided to an agent.

```python theme={null}
class Context(ConfiguredBaseModel):
    description: str
    value: str
```

| Property | Type | Description |
| - | - | - |
| `description` | `str` | Description of what this context represents |
| `value` | `str` | The actual context value |

## Tool

`from ag_ui.core import Tool`

Defines a tool that can be called by an agent.

```python theme={null}
class Tool(ConfiguredBaseModel):
    name: str
    description: str
    parameters: Any  # JSON Schema
```

| Property | Type | Description |
| - | - | - |
| `name` | `str` | Name of the tool |
| `description` | `str` | Description of what the tool does |
| `parameters` | `Any` | JSON Schema defining the parameters for the tool |

## State

`from ag_ui.core import State`

Represents the state of an agent during execution.

```python theme={null}
State = Any
```

The state type is flexible and can hold any data structure needed by the agent
implementation.


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