***

title: add_internal_filler
slug: /reference/python/agents/agent-base/add-internal-filler
description: Add filler phrases for a specific internal/native SWAIG function and language.
max-toc-depth: 3
---------------------

For a complete index of all SignalWire documentation pages, fetch https://signalwire.com/docs/llms.txt

[ref-agentbase]: /docs/server-sdks/reference/python/agents/agent-base

Add filler phrases for a specific internal/native SWAIG function and language.

## **Parameters**

<ParamField path="function_name" type="str" required={true} toc={true}>
  Name of the SWAIG function (e.g., `"next_step"`, `"check_time"`).
</ParamField>

<ParamField path="language_code" type="str" required={true} toc={true}>
  Language code (e.g., `"en-US"`, `"es"`, `"fr"`).
</ParamField>

<ParamField path="fillers" type="list[str]" required={true} toc={true}>
  List of filler phrases for this function and language. The AI randomly selects
  from this list each time the function is invoked.
</ParamField>

## **Returns**

[`AgentBase`][ref-agentbase] -- Returns self for method chaining.

## **Example**

```python {5,9}
from signalwire import AgentBase

agent = AgentBase(name="support", route="/support")
agent.set_prompt_text("You are a helpful assistant.")
agent.add_internal_filler(
    "next_step", "en-US",
    ["Moving to the next step...", "Great, let's continue..."]
)
agent.add_internal_filler(
    "next_step", "es",
    ["Pasando al siguiente paso...", "Continuemos..."]
)
agent.serve()
```