docs: add OrcaRouterChatGenerator documentation page

docs-website/docs/pipeline-components/generators.mdx

@@ -47,6 +47,7 @@ Generators are responsible for generating text after you give them a prompt. The
 | [OpenAIImageGenerator](generators/openaiimagegenerator.mdx)                   | Generate images using OpenAI's image generation models such as `gpt-image-2`.                                                                                                                                            | ❌                 |
 | [OpenAIResponsesChatGenerator](generators/openairesponseschatgenerator.mdx)   | Enables chat completion using OpenAI's Responses API with support for reasoning models.                                                                                                                                  | ✅                 |
 | [OpenRouterChatGenerator](generators/openrouterchatgenerator.mdx)               | Enables chat completion with any model hosted on OpenRouter.                                                                                                                                                             | ✅                 |
+| [OrcaRouterChatGenerator](generators/orcarouterchatgenerator.mdx)               | Enables chat completion using models routed through OrcaRouter.                                                                                                                                                          | ✅                 |
 | [PerplexityChatGenerator](generators/perplexitychatgenerator.mdx)               | Enables chat completion using models via the Perplexity Agent API.                                                                                                                                                       | ✅                 |
 | [SagemakerGenerator](generators/sagemakergenerator.mdx)                       | Enables text generation using LLMs deployed on Amazon Sagemaker.                                                                                                                                                         | ❌                 |
 | [STACKITChatGenerator](generators/stackitchatgenerator.mdx)                     | Enables chat completions using the STACKIT API.                                                                                                                                                                          | ✅                 |

docs-website/docs/pipeline-components/generators/orcarouterchatgenerator.mdx

@@ -0,0 +1,167 @@
+---
+title: "OrcaRouterChatGenerator"
+id: orcarouterchatgenerator
+slug: "/orcarouterchatgenerator"
+description: "This component enables chat completion through [OrcaRouter](https://www.orcarouter.ai/), an OpenAI-compatible model routing gateway."
+---
+
+# OrcaRouterChatGenerator
+
+This component enables chat completion through [OrcaRouter](https://www.orcarouter.ai/), an OpenAI-compatible model routing gateway.
+
+<div className="key-value-table">
+
+|  |  |
+| --- | --- |
+| **Most common position in a pipeline** | After a [ChatPromptBuilder](../builders/chatpromptbuilder.mdx)                                                                |
+| **Mandatory init variables**           | `api_key`: An OrcaRouter API key. Can be set with `ORCAROUTER_API_KEY` env variable or passed to `init()` method. |
+| **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                                                       |
+| **API reference**                      | [OrcaRouter](/reference/integrations-orcarouter)                                                                         |
+| **GitHub link**                        | https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/orcarouter                      |
+| **Package name** | `orcarouter-haystack` |
+
+</div>
+
+## Overview
+
+The `OrcaRouterChatGenerator` enables you to use models from multiple providers (such as `openai/gpt-4o-mini`, `anthropic/claude-opus-4.8`, and `google/gemini-2.5-flash`) by making chat completion calls to the [OrcaRouter API](https://docs.orcarouter.ai). Models are addressed with a `provider/model` namespace, and you can browse the available models in the [OrcaRouter model catalog](https://www.orcarouter.ai/models).
+
+This generator also supports OrcaRouter-specific features such as:
+
+- Automatic routing with the `orcarouter/auto` model, which lets OrcaRouter pick a live upstream model per request based on the policy configured in your OrcaRouter console.
+- Provider routing and model fallback that are configurable with the `generation_kwargs` parameter during initialization or runtime. OrcaRouter-specific routing options are forwarded to the gateway through `extra_body`.
+
+This component uses the same `ChatMessage` format as other Haystack Chat Generators for structured input and output. For more information, see the [ChatMessage documentation](../../concepts/data-classes/chatmessage.mdx).
+
+### Tool Support
+
+`OrcaRouterChatGenerator` supports function calling through the `tools` parameter, which accepts flexible tool configurations:
+
+- **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
+
+This allows you to organize related tools into logical groups while also including standalone tools as needed.
+
+```python
+from haystack.tools import Tool, Toolset
+from haystack_integrations.components.generators.orcarouter import OrcaRouterChatGenerator
+
+# Create individual tools
+weather_tool = Tool(name="weather", description="Get weather info", ...)
+news_tool = Tool(name="news", description="Get latest news", ...)
+
+# Group related tools into a toolset
+math_toolset = Toolset([add_tool, subtract_tool, multiply_tool])
+
+# Pass mixed tools and toolsets to the generator
+generator = OrcaRouterChatGenerator(
+    tools=[math_toolset, weather_tool, news_tool]  # Mix of Toolset and Tool objects
+)
+```
+
+For more details on working with tools, see the [Tool](../../tools/tool.mdx) and [Toolset](../../tools/toolset.mdx) documentation.
+
+### Initialization
+
+To use this integration, you need an OrcaRouter API key. You can provide it with the `ORCAROUTER_API_KEY` environment variable or by using a [Secret](../../concepts/secret-management.mdx).
+
+Then, install the `orcarouter-haystack` integration:
+
+```shell
+pip install orcarouter-haystack
+```
+
+### Streaming
+
+`OrcaRouterChatGenerator` supports [streaming](guides-to-generators/choosing-the-right-generator.mdx#streaming-support) responses from the LLM, allowing tokens to be emitted as they are generated. To enable streaming, pass a callable to the `streaming_callback` parameter during initialization.
+
+## Usage
+
+### On its own
+
+```python
+from haystack.dataclasses import ChatMessage
+from haystack_integrations.components.generators.orcarouter import (
+    OrcaRouterChatGenerator,
+)
+
+client = OrcaRouterChatGenerator(model="openai/gpt-4o-mini")
+response = client.run([ChatMessage.from_user("What are Agentic Pipelines? Be brief.")])
+print(response["replies"][0].text)
+```
+
+With automatic routing and streaming:
+
+```python
+from haystack.dataclasses import ChatMessage
+from haystack_integrations.components.generators.orcarouter import (
+    OrcaRouterChatGenerator,
+)
+
+client = OrcaRouterChatGenerator(
+    model="orcarouter/auto",
+    streaming_callback=lambda chunk: print(chunk.content, end="", flush=True),
+)
+
+response = client.run([ChatMessage.from_user("What are Agentic Pipelines? Be brief.")])
+
+# check the model used for the response
+print("\n\n Model used: ", response["replies"][0].meta["model"])
+```
+
+With a fallback chain:
+
+```python
+from haystack.dataclasses import ChatMessage
+from haystack_integrations.components.generators.orcarouter import (
+    OrcaRouterChatGenerator,
+)
+
+client = OrcaRouterChatGenerator(
+    model="openai/gpt-4o-mini",
+    generation_kwargs={
+        "extra_body": {
+            "route": "fallback",
+            "models": [
+                "openai/gpt-4o-mini",
+                "anthropic/claude-haiku-4.5",
+                "google/gemini-2.5-flash",
+            ],
+        }
+    },
+)
+
+response = client.run([ChatMessage.from_user("What is Haystack?")])
+print(response["replies"][0].text)
+```
+
+### In a pipeline
+
+```python
+from haystack import Pipeline
+from haystack.components.builders import ChatPromptBuilder
+from haystack.dataclasses import ChatMessage
+from haystack_integrations.components.generators.orcarouter import (
+    OrcaRouterChatGenerator,
+)
+
+prompt_builder = ChatPromptBuilder()
+llm = OrcaRouterChatGenerator(model="openai/gpt-4o-mini")
+
+pipe = Pipeline()
+pipe.add_component("builder", prompt_builder)
+pipe.add_component("llm", llm)
+pipe.connect("builder.prompt", "llm.messages")
+
+messages = [
+    ChatMessage.from_system("Give brief answers."),
+    ChatMessage.from_user("Tell me about {{city}}"),
+]
+
+response = pipe.run(
+    data={"builder": {"template": messages, "template_variables": {"city": "Berlin"}}},
+)
+print(response)
+```

docs-website/sidebars.js

@@ -448,6 +448,7 @@ export default {
             'pipeline-components/generators/openaigenerator',
             'pipeline-components/generators/openaiimagegenerator',
             'pipeline-components/generators/openrouterchatgenerator',
+            'pipeline-components/generators/orcarouterchatgenerator',
             'pipeline-components/generators/perplexitychatgenerator',
             'pipeline-components/generators/sagemakergenerator',
             'pipeline-components/generators/stackitchatgenerator',

docs-website/versioned_docs/version-2.31/pipeline-components/generators.mdx

@@ -47,6 +47,7 @@ Generators are responsible for generating text after you give them a prompt. The
 | [OpenAIGenerator](generators/openaigenerator.mdx)                             | Enables text generation using OpenAI's large language models (LLMs).                                                                                                                                                     | ✅                 |
 | [OpenAIResponsesChatGenerator](generators/openairesponseschatgenerator.mdx)   | Enables chat completion using OpenAI's Responses API with support for reasoning models.                                                                                                                                  | ✅                 |
 | [OpenRouterChatGenerator](generators/openrouterchatgenerator.mdx)               | Enables chat completion with any model hosted on OpenRouter.                                                                                                                                                             | ✅                 |
+| [OrcaRouterChatGenerator](generators/orcarouterchatgenerator.mdx)               | Enables chat completion using models routed through OrcaRouter.                                                                                                                                                          | ✅                 |
 | [PerplexityChatGenerator](generators/perplexitychatgenerator.mdx)               | Enables chat completion using models via the Perplexity Agent API.                                                                                                                                                       | ✅                 |
 | [SagemakerGenerator](generators/sagemakergenerator.mdx)                       | Enables text generation using LLMs deployed on Amazon Sagemaker.                                                                                                                                                         | ❌                 |
 | [STACKITChatGenerator](generators/stackitchatgenerator.mdx)                     | Enables chat completions using the STACKIT API.                                                                                                                                                                          | ✅                 |

docs-website/versioned_sidebars/version-2.31-sidebars.json

@@ -442,6 +442,7 @@
             "pipeline-components/generators/openairesponseschatgenerator",
             "pipeline-components/generators/openaigenerator",
             "pipeline-components/generators/openrouterchatgenerator",
+            "pipeline-components/generators/orcarouterchatgenerator",
             "pipeline-components/generators/perplexitychatgenerator",
             "pipeline-components/generators/sagemakergenerator",
             "pipeline-components/generators/stackitchatgenerator",
@@ -799,4 +800,4 @@
       ]
     }
   ]
-}
+}