---
title: "AnthropicFoundryChatGenerator"
id: anthropicfoundrychatgenerator
slug: "/anthropicfoundrychatgenerator"
description: "This component enables chat completions using Anthropic models served through Azure Foundry."
---

# AnthropicFoundryChatGenerator

This component enables chat completions using Anthropic models served through Azure Foundry.

<div className="key-value-table">

|  |  |
| --- | --- |
| **Most common position in a pipeline** | After a [`ChatPromptBuilder`](../builders/chatpromptbuilder.mdx) |
| **Mandatory init variables** | `api_key`: Your Azure Foundry API key. Can be set with the `ANTHROPIC_FOUNDRY_API_KEY` env var. Alternatively, pass an `azure_ad_token_provider` callable.  <br /> <br />`resource`: Your Azure Foundry resource name. Can be set with the `ANTHROPIC_FOUNDRY_RESOURCE` env var. Alternatively, pass a full `endpoint` URL. |
| **Mandatory run variables** | `messages`: A list of [`ChatMessage`](../../concepts/data-classes/chatmessage.mdx) objects |
| **Output variables** | `replies`: A list of [`ChatMessage`](../../concepts/data-classes/chatmessage.mdx) objects  <br /> <br />`meta`: A dictionary on each reply with metadata such as the model name, finish reason, and token usage |
| **API reference** | [Anthropic](/reference/integrations-anthropic) |
| **GitHub link** | https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/anthropic |
| **Package name** | `anthropic-haystack` |

</div>

## Overview

`AnthropicFoundryChatGenerator` lets you call Anthropic's Claude models through an [Azure Foundry](https://learn.microsoft.com/en-us/azure/ai-foundry/) deployment. It is a thin subclass of [`AnthropicChatGenerator`](anthropicchatgenerator.mdx) — the request and response shapes match the Anthropic Messages API, but the traffic flows through your Azure resource instead of `api.anthropic.com`.

Use this generator when your organization standardizes on Azure for model hosting (billing, networking, compliance) but still wants to work against Claude. If you don't need Azure, prefer `AnthropicChatGenerator`.

The default model is `claude-sonnet-4-5`. Other models known to work include `claude-opus-4-6`, `claude-sonnet-4-6`, `claude-opus-4-5`, `claude-opus-4-1`, and `claude-haiku-4-5`. This list is not exhaustive — the actual catalog depends on what is deployed in your Foundry resource. See the [Anthropic model overview](https://docs.anthropic.com/en/docs/about-claude/models) for guidance on picking a model.

### Parameters

`AnthropicFoundryChatGenerator` needs two things to talk to Azure: credentials and an endpoint.

**Credentials.** Pick one of:

- The `ANTHROPIC_FOUNDRY_API_KEY` environment variable (recommended).
- The `api_key` init parameter using the Haystack [Secret](../../concepts/secret-management.mdx) API: `Secret.from_token("your-api-key-here")`.
- A callable passed as `azure_ad_token_provider` that returns a fresh Azure AD token on demand. Use this for Entra ID / managed-identity setups where a static key isn't appropriate.

**Endpoint.** Pick one of:

- The `resource` init parameter (or the `ANTHROPIC_FOUNDRY_RESOURCE` environment variable) — the short Foundry resource name, used to derive the URL.
- The `endpoint` init parameter — a full URL, useful for custom domains or non-standard routes.

Once configured, pass any text-generation parameter supported by the Anthropic [Messages API](https://docs.anthropic.com/en/api/messages) through `generation_kwargs`, either at init or per call. Common keys include `system`, `max_tokens`, `temperature`, `top_p`, `top_k`, `stop_sequences`, `metadata`, and `extra_headers`. You can also tune `timeout` and `max_retries` to control client-side resilience.

The component takes a list of `ChatMessage` objects. `ChatMessage` is a data class that holds a message, a role (`user`, `assistant`, `system`, or `function`), and optional metadata. Only text input is supported.

### Tool Support

`AnthropicFoundryChatGenerator` supports function calling through the `tools` parameter, which accepts:

- **A list of Tool objects**: Pass individual tools as a list.
- **A single Toolset**: Pass an entire Toolset directly.
- **Mixed Tools and Toolsets**: Combine multiple Toolsets with standalone tools in a single list.

```python
from haystack.tools import Tool, Toolset
from haystack_integrations.components.generators.anthropic import AnthropicFoundryChatGenerator

weather_tool = Tool(name="weather", description="Get weather info", ...)
math_toolset = Toolset([add_tool, subtract_tool, multiply_tool])

generator = AnthropicFoundryChatGenerator(
    resource="my-resource",
    tools=[math_toolset, weather_tool],
)
```

Tools passed to `run()` override any tools set at init time. For more details, see the [Tool](../../tools/tool.mdx) and [Toolset](../../tools/toolset.mdx) documentation.

### Streaming

You can stream output as it's generated. Pass a callback to `streaming_callback`. The built-in `print_streaming_chunk` prints text tokens and tool events to stdout.

```python
from haystack.components.generators.utils import print_streaming_chunk
from haystack.dataclasses import ChatMessage
from haystack_integrations.components.generators.anthropic import AnthropicFoundryChatGenerator

generator = AnthropicFoundryChatGenerator(
    resource="my-resource",
    streaming_callback=print_streaming_chunk,
)
generator.run([ChatMessage.from_user("Your question here")])
```

:::info
Streaming works only with a single response. If a provider supports multiple candidates, set `n=1`.
:::

See [Streaming Support](guides-to-generators/choosing-the-right-generator.mdx#streaming-support) for how `StreamingChunk` works and how to write a custom callback. Prefer `print_streaming_chunk` unless you need a specific transport (such as SSE or WebSocket) or custom UI formatting.

### Async

`run_async` mirrors `run` and is wired up automatically — useful inside an async pipeline or web handler.

```python
import asyncio
from haystack.dataclasses import ChatMessage
from haystack_integrations.components.generators.anthropic import AnthropicFoundryChatGenerator

async def main():
    generator = AnthropicFoundryChatGenerator(resource="my-resource")
    result = await generator.run_async([ChatMessage.from_user("Hello!")])
    print(result["replies"][0].text)

asyncio.run(main())
```

## Usage

Install the `anthropic-haystack` package to use the `AnthropicFoundryChatGenerator`:

```shell
pip install anthropic-haystack
```

### On its own

```python
from haystack.dataclasses import ChatMessage
from haystack.utils import Secret
from haystack_integrations.components.generators.anthropic import AnthropicFoundryChatGenerator

generator = AnthropicFoundryChatGenerator(
    model="claude-sonnet-4-5",
    api_key=Secret.from_env_var("ANTHROPIC_FOUNDRY_API_KEY"),
    resource="my-resource",
)

response = generator.run([ChatMessage.from_user("What's Natural Language Processing?")])
print(response)
```

### In a pipeline

```python
from haystack import Pipeline
from haystack.components.builders import ChatPromptBuilder
from haystack.dataclasses import ChatMessage
from haystack_integrations.components.generators.anthropic import AnthropicFoundryChatGenerator

pipe = Pipeline()
pipe.add_component("prompt_builder", ChatPromptBuilder())
pipe.add_component(
    "llm",
    AnthropicFoundryChatGenerator(resource="my-resource"),
)
pipe.connect("prompt_builder", "llm")

country = "Germany"
messages = [
    ChatMessage.from_system(
        "You are an assistant giving out valuable information to language learners.",
    ),
    ChatMessage.from_user("What's the official language of {{ country }}?"),
]

res = pipe.run(
    data={
        "prompt_builder": {
            "template_variables": {"country": country},
            "template": messages,
        },
    },
)
print(res)
```