Daria Fokina 3e81ec75dc
docs: add 2.18 and 2.19 actual documentation pages (#9946)
* versioned-docs

* external-documentstores
2025-10-27 13:03:22 +01:00

60 lines
3.3 KiB
Plaintext
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

---
title: "AnswerJoiner"
id: answerjoiner
slug: "/answerjoiner"
description: "Merges multiple answers from different Generators into a single list."
---
# AnswerJoiner
Merges multiple answers from different Generators into a single list.
| | |
| :------------------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Most common position in a pipeline** | In query pipelines, after [Generators](../generators.mdx) and, subsequently, components that return a list of answers such as [`AnswerBuilder`](../builders/answerbuilder.mdx) |
| **Mandatory run variables** | “answers”: A nested list of answers to be merged, received from the Generator. This input is `variadic`, meaning you can connect a variable number of components to it. |
| **Output variables** | “answers”: A merged list of answers |
| **API reference** | [Joiners](/reference/joiners-api) |
| **GitHub link** | https://github.com/deepset-ai/haystack/blob/main/haystack/components/joiners/answer_joiner.py |
## Overvew
`AnswerJoiner` joins input lists of [`Answer`](/docs/data-classes#answer) objects from multiple connections and returns them as one list.
You can optionally set the `top_k` parameter, which specifies the maximum number of answers to return. If you dont set this parameter, the component returns all answers it receives.
## Usage
In this simple example pipeline, the `AnswerJoiner` merges answers from two instances of Generators:
```python
from haystack.components.builders import AnswerBuilder
from haystack.components.joiners import AnswerJoiner
from haystack.core.pipeline import Pipeline
from haystack.components.generators.chat import OpenAIChatGenerator
from haystack.dataclasses import ChatMessage
query = "What's Natural Language Processing?"
messages = [ChatMessage.from_system("You are a helpful, respectful and honest assistant. Be super concise."),
ChatMessage.from_user(query)]
pipe = Pipeline()
pipe.add_component("gpt-4o", OpenAIChatGenerator(model="gpt-4o"))
pipe.add_component("llama", OpenAIChatGenerator(model="gpt-3.5-turbo"))
pipe.add_component("aba", AnswerBuilder())
pipe.add_component("abb", AnswerBuilder())
pipe.add_component("joiner", AnswerJoiner())
pipe.connect("gpt-4o.replies", "aba")
pipe.connect("llama.replies", "abb")
pipe.connect("aba.answers", "joiner")
pipe.connect("abb.answers", "joiner")
results = pipe.run(data={"gpt-4o": {"messages": messages},
"llama": {"messages": messages},
"aba": {"query": query},
"abb": {"query": query}})
```