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

# BaseEnvironment

> The environment abstraction for interacting with tool servers

The environment is the interface your agent uses to discover and call tools at runtime.

## Methods

| Method                                                 | Description                                                                          |
| ------------------------------------------------------ | ------------------------------------------------------------------------------------ |
| `async alist_tools(tool_server=None)`                  | Returns tool definitions (all servers, or a specific one)                            |
| `async acall_tool(tool_server, tool_name, parameters)` | Invokes a tool and returns a `ToolCallResult`                                        |
| `list_tool_namespaces()`                               | Returns `list[ToolNamespace]` describing available tool servers and their transports |
| `list_tools(tool_server=None)`                         | **Deprecated (removal in 0.4.0)** — sync wrapper around `alist_tools()`              |
| `call_tool(tool_server, tool_name, parameters)`        | **Deprecated (removal in 0.4.0)** — sync wrapper around `acall_tool()`               |

<Note>Since `BaseAgent.setup()` and `run()` are synchronous, the deprecated sync wrappers (`list_tools`, `call_tool`) are still usable from agent code. They run the async methods internally via a compatibility shim.</Note>

## UnifiedToolEnvironment

SimLab ships `UnifiedToolEnvironment`, which implements `BaseEnvironment` over HTTP and MCP transports against the [Tool Server Protocol](/api-reference/tool-server-protocol).

```python theme={null}
from simlab.agents import UnifiedToolEnvironment

env = UnifiedToolEnvironment(
    tool_servers={
        "email": "https://<environment-url>/email",
        "calendar": "https://<environment-url>/calendar",
    },
    timeout_seconds=30.0,
)

tools = env.list_tools()
result = env.call_tool("email", "send_email", {"to": "...", "subject": "...", "body": "..."})
```