migration.mdx
  1  ---
  2  title: "Migration Guide"
  3  id: migration
  4  slug: "/migration"
  5  description: "Learn how to make the move to Haystack 2.x from Haystack 1.x."
  6  ---
  7  
  8  # Migration Guide
  9  
 10  Learn how to make the move to Haystack 2.x from Haystack 1.x.
 11  
 12  This guide is designed for those with previous experience with Haystack and who are interested in understanding the differences between Haystack 1.x and Haystack 2.x. If you're new to Haystack, skip this page and proceed directly to Haystack 2.x [documentation](get-started.mdx).
 13  
 14  ## Major Changes
 15  
 16  Haystack 2.x represents a significant overhaul of Haystack 1.x, and it's important to note that certain key concepts outlined in this section don't have a direct correlation between the two versions.
 17  
 18  ### Package Name
 19  
 20  Haystack 1.x was distributed with a package called `farm-haystack`. To migrate your application, you must uninstall `farm-haystack` and install the new `haystack-ai` package for Haystack 2.x.
 21  
 22  :::warning
 23  Two versions of the project cannot coexist in the same Python environment.
 24  
 25  One of the options is to remove both packages if they are installed in the same environment, followed by installing only one of them:
 26  
 27  ```bash
 28  pip uninstall -y farm-haystack haystack-ai
 29  pip install haystack-ai
 30  ```
 31  :::
 32  
 33  ### Nodes
 34  
 35  While Haystack 2.x continues to rely on the `Pipeline` abstraction, the elements linked in a pipeline graph are now referred to as just _components_, replacing the terms _nodes_ and _pipeline components_ used in the previous versions. The [_Migrating Components_](#migrating-components) paragraph below outlines which component in Haystack 2.x can be used as a replacement for a specific 1.x node.
 36  
 37  ### Pipelines
 38  
 39  Pipelines continue to serve as the fundamental structure of all Haystack applications. While the concept of `Pipeline` abstraction remains consistent, Haystack 2.x introduces significant enhancements that address various limitations of its predecessor. For instance, the pipelines now support loops. Pipelines also offer greater flexibility in their input, which is no longer restricted to queries. The pipeline now allows to route the output of a component to multiple recipients. This increases flexibility, however, comes with notable differences in the pipeline definition process in Haystack 2.x compared to the previous version.
 40  
 41  In Haystack 1.x, a pipeline was built by adding one node after the other. In the resulting pipeline graph, edges are automatically added to connect those nodes in the order they were added.
 42  
 43  Building a pipeline in Haystack 2.x is a two-step process:
 44  
 45  1. Initially, components are added to the pipeline without any specific order by calling the `add_component` method.
 46  2. Subsequently, the components must be explicitly connected by calling the `connect` method to define the final graph.
 47  
 48  To migrate an existing pipeline, the first step is to go through the nodes and identify their counterparts in Haystack 2.x (see the following section,  [_Migrating Components_](#migrating-components), for guidance). If all the nodes can be replaced by corresponding components, they have to be added to the pipeline with `add_component` and explicitly connected with the appropriate calls to `connect`. Here is an example:
 49  
 50  **Haystack 1.x**
 51  
 52  ```python
 53  pipeline = Pipeline()
 54  
 55  node_1 = SomeNode()
 56  node_2 = AnotherNode()
 57  
 58  pipeline.add_node(node_1, name="Node_1", inputs=["Query"])
 59  pipeline.add_node(node_2, name="Node_2", inputs=["Node_1"])
 60  ```
 61  
 62  **Haystack 2.x**
 63  
 64  ```python
 65  pipeline = Pipeline()
 66  
 67  component_1 = SomeComponent()
 68  component_2 = AnotherComponent()
 69  
 70  pipeline.add_component("Comp_1", component_1)
 71  pipeline.add_component("Comp_2", component_2)
 72  
 73  pipeline.connect("Comp_1", "Comp_2")
 74  ```
 75  
 76  In case a specific replacement component is not available for one of your nodes, migrating the pipeline might still be possible by:
 77  
 78  - Either [creating a custom component](../concepts/components/custom-components.mdx), or
 79  - Changing the pipeline logic, as the last resort.
 80  
 81  :::note
 82  Check out the [Pipelines](../concepts/pipelines.mdx) section of our 2.x documentation to understand how new pipelines work more granularly.
 83  
 84  :::
 85  
 86  ### Document Stores
 87  
 88  The fundamental concept of Document Stores as gateways to access text and metadata stored in a database didn’t change in Haystack 2.x, but there are significant differences against Haystack 1.x.
 89  
 90  In Haystack 1.x, Document Stores were a special type of node that you can use in two ways:
 91  
 92  - As the last node in an indexing pipeline (such as a pipeline whose ultimate goal is storing data in a database).
 93  - As a normal Python instance passed to a Retriever node.
 94  
 95  In Haystack 2.x, the Document Store is not a component, so to migrate the two use cases above to version 2.x, you can respectively:
 96  
 97  - Replace the Document Store at the end of the pipeline with a [`DocumentWriter`](../pipeline-components/writers/documentwriter.mdx)  component.
 98  - Identify the right Retriever component and create it passing the Document Store instance, same as it is in Haystack 1.x.
 99  
100  ### Retrievers
101  
102  Haystack 1.x provided a set of nodes that filter relevant documents from different data sources according to a given query. Each of those nodes implements a certain retrieval algorithm and supports one or more types of Document Stores. For example, the `BM25Retriever` node in Haystack 1.x can work seamlessly with OpenSearch and Elasticsearch but not with Qdrant; the `EmbeddingRetriever`, on the contrary, can work with all the three databases.
103  
104  In Haystack 2.x, the concept is flipped, and each Document Store provides one or more retriever components, depending on which retrieval methods the underlying vector database supports. For example, the `OpenSearchDocumentStore` comes with [two Retriever components](../document-stores/opensearch-document-store.mdx#supported-retrievers), one relying on BM25, and the other on vector similarity.
105  
106  To migrate a 1.x retrieval pipeline to 2.x, the first step is to identify the Document Store being used and replace the Retriever node with the corresponding Retriever component from Haystack 2.x with the Document Store of choice. For example, a `BM25Retriever` node using Elasticsearch in a Haystack 1.x pipeline should be replaced with the [`ElasticsearchBM25Retriever`](../pipeline-components/retrievers/elasticsearchbm25retriever.mdx)  component.
107  
108  ### PromptNode
109  
110  The `PromptNode`  in Haystack 1.x represented the gateway to any Large Language Model (LLM) inference provider, whether it is locally available or remote. Based on the name of the model, Haystack infers the right provider to call and forward the query.
111  
112  In Haystack 2.x, the task of using LLMs is assigned to [Generators](../pipeline-components/generators.mdx). These are a set of components that are highly specialized and tailored for each inference provider.
113  
114  The first step when migrating a pipeline with a `PromptNode` is to identify the model provider used and to replace the node with two components:
115  
116  - A Generator component for the model provider of choice,
117  - A `PromptBuilder` or `ChatPromptBuilder` component to build the prompt to be used.
118  
119  The [_Migration examples_](#migration-examples) section below shows how to port a `PromptNode` using OpenAI with a prompt template to a corresponding Haystack 2.x pipeline using the `OpenAIGenerator` in conjunction with a `PromptBuilder` component.
120  
121  ### Agents
122  
123  The agentic approach facilitates the answering of questions that are significantly more complex than those typically addressed by extractive or generative question answering techniques.
124  
125  Haystack 1.x provided Agents, enabling the use of LLMs in a loop.
126  
127  Currently in Haystack 2.x, you can build Agents using three main elements in a pipeline: Chat Generators, ToolInvoker component, and Tools. A standalone Agent abstraction in Haystack 2.x is in an experimental phase.
128  
129  :::note[Agents Documentation Page]
130  
131  Take a look at our 2.x [Agents](../concepts/agents.mdx) documentation page for more information and detailed examples.
132  :::
133  
134  ### REST API
135  
136  Haystack 1.x enabled the deployment of pipelines through a RESTful API over HTTP. This feature is facilitated by a separate application named `rest_api` which is exclusively accessible in the form of a [source code on GitHub](https://github.com/deepset-ai/haystack/tree/v1.x/rest_api).
137  
138  Haystack 2.x takes the same RESTful approach, but in this case, the application to be used to deploy pipelines is called [Hayhooks](../development/hayhooks.mdx) and can be installed with `pip install hayhooks`.
139  
140  At the moment, porting an existing Haystack 1.x deployment using the `rest_api` project to Hayhooks would require a complete rewrite of the application.
141  
142  ## Dependencies
143  
144  In order to minimize runtime errors, Haystack 1.x was distributed in a package that’s quite large, as it tries to set up the Python environment with as many dependencies as possible.
145  
146  In contrast, Haystack 2.x strives for a more streamlined approach, offering a minimal set of dependencies right out of the box. It features a system that issues a warning when an additional dependency is required, thereby providing the user with the necessary instructions.
147  
148  To make sure all the dependencies are satisfied when migrating a Haystack 1.x application to version 2.x, a good strategy is to run end-to-end tests and cover all the execution paths to ensure all the required dependencies are available in the target Python environment.
149  
150  ## Migrating Components
151  
152  This table outlines which component (or a group of components) can be used to replace a certain node when porting a Haystack 1.x pipeline to the latest 2.x version. It’s important to note that when a Haystack 2.x replacement is not available, this doesn’t necessarily mean we are planning this feature.
153  
154  If you need help migrating a 1.x node without a 2.x counterpart, open an [issue](https://github.com/deepset-ai/haystack/issues) in Haystack GitHub repository.
155  
156  ### Data Handling
157  
158  | Haystack 1.x               | Description                                                                                                                                                                             | Haystack 2.x                                                                         |
159  | -------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------ |
160  | Crawler                    | Scrapes text from websites. **Example usage:** To run searches on your website content.                                                                                                 | Not Available                                                                        |
161  | DocumentClassifier         | Classifies documents by attaching metadata to them. **Example usage:** Labeling documents by their characteristic (for example, sentiment).                                             | [TransformersZeroShotDocumentClassifier](../pipeline-components/classifiers/transformerszeroshotdocumentclassifier.mdx) |
162  | DocumentLanguageClassifier | Detects the language of the documents you pass to it and adds it to the document metadata.                                                                                              | [DocumentLanguageClassifier](../pipeline-components/classifiers/documentlanguageclassifier.mdx)                       |
163  | EntityExtractor            | Extracts predefined entities out of a piece of text. **Example usage:** Named entity extraction (NER).                                                                                  | [NamedEntityExtractor](../pipeline-components/extractors/namedentityextractor.mdx)                                   |
164  | FileClassifier             | Distinguishes between text, PDF, Markdown, Docx, and HTML files. **Example usage:** Routing files to appropriate converters (for example, it routes PDF files to `PDFToTextConverter`). | [FileTypeRouter](../pipeline-components/routers/filetyperouter.mdx)                                               |
165  | FileConverter              | Cleans and splits documents in different formats. **Example usage:** In indexing pipelines, extracting text from a file and casting it into the Document class format.                  | [Converters](../pipeline-components/converters.mdx)                                                       |
166  | PreProcessor               | Cleans and splits documents. **Example usage:** Normalizing white spaces, getting rid of headers and footers, splitting documents into smaller ones.                                    | [PreProcessors](../pipeline-components/preprocessors.mdx)                                                 |
167  
168  ### Semantic Search
169  
170  | Haystack 1.x      | Description                                                                                                                                                                                                                 | Haystack 2.x                                                                            |
171  | ----------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------- |
172  | Ranker            | Orders documents based on how relevant they are to the query. **Example usage:** In a query pipeline, after a keyword-based Retriever to rank the documents it returns.                                                     | [Rankers](../pipeline-components/rankers.mdx)                                                                |
173  | Reader            | Finds an answer by selecting a text span in documents. **Example usage:** In a query pipeline when you want to know the location of the answer.                                                                             | [ExtractiveReader](../pipeline-components/readers/extractivereader.mdx)                                              |
174  | Retriever         | Fetches relevant documents from the Document Store. **Example usage:** Coupling Retriever with a Reader in a query pipeline to speed up the search (the Reader only goes through the documents it gets from the Retriever). | [Retrievers](../pipeline-components/retrievers.mdx)                                                          |
175  | QuestionGenerator | When given a document, it generates questions this document can answer. **Example usage:** Auto-suggested questions in your search app.                                                                                     | Prompt [Builders](../pipeline-components/builders.mdx) with dedicated prompt, [Generators](../pipeline-components/generators.mdx) |
176  
177  ### Prompts and LLMs
178  
179  | Haystack 1.x | Description                                                                                                                                                                                                                   | Haystack 2.x                                                     |
180  | ------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------- |
181  | PromptNode   | Uses large language models to perform various NLP tasks in a pipeline or on its own. **Example usage:** It's a very versatile component that can perform tasks like summarization, question answering, translation, and more. | Prompt [Builders](../pipeline-components/builders.mdx),[Generators](../pipeline-components/generators.mdx) |
182  
183  ### Routing
184  
185  | Haystack 1.x | Description | Haystack 2.x |
186  | --- | --- | --- |
187  | QueryClassifier | Categorizes queries. **Example usage:** Distinguishing between keyword queries and natural language questions and routing them to the Retrievers that can handle them best. | [TransformersZeroShotTextRouter](../pipeline-components/routers/transformerszeroshottextrouter.mdx)  <br />[TransformersTextRouter](../pipeline-components/routers/transformerstextrouter.mdx) |
188  | RouteDocuments | Routes documents to different branches of your pipeline based on their content type or metadata field. **Example usage:** Routing table data to `TableReader` and text data to `TransfomersReader` for better handling. | [Routers](../pipeline-components/routers.mdx) |
189  
190  ### Utility Components
191  
192  | Haystack 1.x            | Description                                                                                                                                                                                                                                                                                                                                            | Haystack 2.x                                                                            |
193  | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------- |
194  | DocumentMerger          | Concatenates multiple documents into a single one. **Example usage: **Merge the documents to summarize in a summarization pipeline.                                                                                                                                                                                                                    | Prompt [Builders](../pipeline-components/builders.mdx)                                                       |
195  | Docs2Answers            | Converts Documents into Answers. **Example usage:** When using REST API for document retrieval. REST API expects Answer as output, you can use `Doc2Answer` as the last node to convert the retrieved documents to answers.                                                                                                                            | [AnswerBuilder](../pipeline-components/builders/answerbuilder.mdx)                                                    |
196  | JoinAnswers             | Takes answers returned by multiple components and joins them in a single list of answers. **Example usage:** For running queries on different document types (for example, tables and text), where the documents are routed to different readers, and each reader returns a separate list of answers.                                                  | [AnswerJoiner](../pipeline-components/joiners/answerjoiner.mdx)                                                        |
197  | JoinDocuments           | Takes documents returned by different components and joins them to form one list of documents. **Example usage:** In document retrieval pipelines, where there are different types of documents, each routed to a different Retriever. Each Retriever returns a separate list of documents, and you can join them into one list using `JoinDocuments`. | [DocumentJoiner](../pipeline-components/joiners/documentjoiner.mdx)                                                  |
198  | Shaper                  | Currently functions mostly as `PromptNode` helper making sure the `PromptNode` input or output is correct. **Example usage:** In a question answering pipeline using `PromptNode`, where the `PromptTemplate` expects questions as input, while Haystack pipelines use query. You can use Shaper to rename queries to questions.                       | Prompt [Builders](../pipeline-components/builders.mdx)                                                       |
199  | Summarizer              | Creates an overview of a document. **Example usage:** To get a glimpse of the documents the Retriever is returning.                                                                                                                                                                                                                                    | Prompt [Builders](../pipeline-components/builders.mdx) with dedicated prompt, [Generators](../pipeline-components/generators.mdx) |
200  | TransformersImageToText | Generates captions for images. **Example usage:** Automatically generate captions for a list of images that you can later use in your knowledge base.                                                                                                                                                                                                  | [VertexAIImageQA](../pipeline-components/generators/vertexaiimageqa.mdx)                                                  |
201  | Translator              | Translates text from one language into another. **Example usage:** Running searches on documents in other languages.                                                                                                                                                                                                                                   | Prompt [Builders](../pipeline-components/builders.mdx) with dedicated prompt, [Generators](../pipeline-components/generators.mdx) |
202  
203  ### Extras
204  
205  | Haystack 1.x     | Description                                                                                                                                                                      | Haystack 2.x                                                                   |
206  | ---------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------ |
207  | AnswerToSpeech   | Converts text answers into speech answers. **Example usage:** Improving accessibility of your search system by providing a way to have the answer and its context read out loud. | [ElevenLabs](https://haystack.deepset.ai/integrations/elevenlabs) Integration  |
208  | DocumentToSpeech | Converts text documents to speech documents. **Example usage:** Improving accessibility of a document retrieval pipeline by providing the option to read documents out loud.     | [ElevenLabs](https://haystack.deepset.ai/integrations/elevenlabs)  Integration |
209  
210  ## Migration examples
211  
212  :::note
213  This section might grow as we assist users with their use cases.
214  
215  :::
216  
217  ### Indexing Pipeline
218  
219  <details>
220  
221  <summary>Haystack 1.x</summary>
222  
223  ```python
224  from haystack.document_stores import InMemoryDocumentStore
225  from haystack.nodes.file_classifier import FileTypeClassifier
226  from haystack.nodes.file_converter import TextConverter
227  from haystack.nodes.preprocessor import PreProcessor
228  from haystack.pipelines import Pipeline
229  
230  ## Initialize a DocumentStore
231  document_store = InMemoryDocumentStore()
232  
233  ## Indexing Pipeline
234  indexing_pipeline = Pipeline()
235  
236  ## Makes sure the file is a TXT file (FileTypeClassifier node)
237  classifier = FileTypeClassifier()
238  indexing_pipeline.add_node(classifier, name="Classifier", inputs=["File"])
239  
240  ## Converts a file into text and performs basic cleaning (TextConverter node)
241  text_converter = TextConverter(remove_numeric_tables=True)
242  indexing_pipeline.add_node(
243      text_converter,
244      name="Text_converter",
245      inputs=["Classifier.output_1"],
246  )
247  
248  ## Pre-processes the text by performing splits and adding metadata to the text (Preprocessor node)
249  preprocessor = PreProcessor(
250      clean_whitespace=True,
251      clean_empty_lines=True,
252      split_length=100,
253      split_overlap=50,
254      split_respect_sentence_boundary=True,
255  )
256  indexing_pipeline.add_node(preprocessor, name="Preprocessor", inputs=["Text_converter"])
257  
258  ## - Writes the resulting documents into the document store
259  indexing_pipeline.add_node(
260      document_store,
261      name="Document_Store",
262      inputs=["Preprocessor"],
263  )
264  
265  ## Then we run it with the documents and their metadata as input
266  result = indexing_pipeline.run(file_paths=file_paths, meta=files_metadata)
267  ```
268  
269  </details>
270  
271  <details>
272  
273  <summary>Haystack 2.x</summary>
274  
275  ```python
276  from haystack import Pipeline
277  from haystack.components.routers import FileTypeRouter
278  from haystack.document_stores.in_memory import InMemoryDocumentStore
279  from haystack.components.converters import TextFileToDocument
280  from haystack.components.preprocessors import DocumentCleaner, DocumentSplitter
281  from haystack.components.writers import DocumentWriter
282  
283  ## Initialize a DocumentStore
284  document_store = InMemoryDocumentStore()
285  
286  ## Indexing Pipeline
287  indexing_pipeline = Pipeline()
288  
289  ## Makes sure the file is a TXT file (FileTypeRouter component)
290  classifier = FileTypeRouter(mime_types=["text/plain"])
291  indexing_pipeline.add_component("file_type_router", classifier)
292  
293  ## Converts a file into a Document (TextFileToDocument component)
294  text_converter = TextFileToDocument()
295  indexing_pipeline.add_component("text_converter", text_converter)
296  
297  ## Performs basic cleaning (DocumentCleaner component)
298  cleaner = DocumentCleaner(
299      remove_empty_lines=True,
300      remove_extra_whitespaces=True,
301  )
302  indexing_pipeline.add_component("cleaner", cleaner)
303  
304  ## Pre-processes the text by performing splits and adding metadata to the text (DocumentSplitter component)
305  preprocessor = DocumentSplitter(split_by="passage", split_length=100, split_overlap=50)
306  indexing_pipeline.add_component("preprocessor", preprocessor)
307  
308  ## - Writes the resulting documents into the document store
309  indexing_pipeline.add_component("writer", DocumentWriter(document_store))
310  
311  ## Connect all the components
312  indexing_pipeline.connect("file_type_router.text/plain", "text_converter")
313  indexing_pipeline.connect("text_converter", "cleaner")
314  indexing_pipeline.connect("cleaner", "preprocessor")
315  indexing_pipeline.connect("preprocessor", "writer")
316  
317  ## Then we run it with the documents and their metadata as input
318  result = indexing_pipeline.run({"file_type_router": {"sources": file_paths}})
319  ```
320  
321  </details>
322  
323  ### Query Pipeline
324  
325  <details>
326  
327  <summary>Haystack 1.x</summary>
328  
329  ```python
330  from haystack.document_stores import InMemoryDocumentStore
331  from haystack.pipelines import ExtractiveQAPipeline
332  from haystack import Document
333  from haystack.nodes import BM25Retriever
334  from haystack.nodes import FARMReader
335  
336  document_store = InMemoryDocumentStore(use_bm25=True)
337  document_store.write_documents(
338      [
339          Document(content="Paris is the capital of France."),
340          Document(content="Berlin is the capital of Germany."),
341          Document(content="Rome is the capital of Italy."),
342          Document(content="Madrid is the capital of Spain."),
343      ],
344  )
345  
346  retriever = BM25Retriever(document_store=document_store)
347  reader = FARMReader(model_name_or_path="deepset/roberta-base-squad2")
348  extractive_qa_pipeline = ExtractiveQAPipeline(reader, retriever)
349  
350  query = "What is the capital of France?"
351  result = extractive_qa_pipeline.run(
352      query=query,
353      params={"Retriever": {"top_k": 10}, "Reader": {"top_k": 5}},
354  )
355  ```
356  
357  </details>
358  
359  <details>
360  
361  <summary>Haystack 2.x</summary>
362  
363  ```python
364  from haystack.document_stores.in_memory import InMemoryDocumentStore
365  from haystack import Document, Pipeline
366  from haystack.components.retrievers.in_memory import InMemoryBM25Retriever
367  from haystack.components.readers import ExtractiveReader
368  
369  document_store = InMemoryDocumentStore()
370  document_store.write_documents(
371      [
372          Document(content="Paris is the capital of France."),
373          Document(content="Berlin is the capital of Germany."),
374          Document(content="Rome is the capital of Italy."),
375          Document(content="Madrid is the capital of Spain."),
376      ],
377  )
378  
379  retriever = InMemoryBM25Retriever(document_store)
380  reader = ExtractiveReader(model="deepset/roberta-base-squad2")
381  extractive_qa_pipeline = Pipeline()
382  extractive_qa_pipeline.add_component("retriever", retriever)
383  extractive_qa_pipeline.add_component("reader", reader)
384  extractive_qa_pipeline.connect("retriever", "reader")
385  
386  query = "What is the capital of France?"
387  result = extractive_qa_pipeline.run(
388      data={
389          "retriever": {"query": query, "top_k": 3},
390          "reader": {"query": query, "top_k": 2},
391      },
392  )
393  ```
394  
395  </details>
396  
397  ### RAG Pipeline
398  
399  <details>
400  
401  <summary>Haystack 1.x</summary>
402  
403  ```python
404  from datasets import load_dataset
405  
406  from haystack.pipelines import Pipeline
407  from haystack.document_stores import InMemoryDocumentStore
408  from haystack.nodes import EmbeddingRetriever, PromptNode, PromptTemplate, AnswerParser
409  
410  document_store = InMemoryDocumentStore(embedding_dim=384)
411  dataset = load_dataset("bilgeyucel/seven-wonders", split="train")
412  document_store.write_documents(dataset)
413  retriever = EmbeddingRetriever(
414      embedding_model="sentence-transformers/all-MiniLM-L6-v2",
415      document_store=document_store,
416      top_k=2,
417  )
418  document_store.update_embeddings(retriever)
419  
420  rag_prompt = PromptTemplate(
421      prompt="""Synthesize a comprehensive answer from the following text for the given question.
422                               Provide a clear and concise response that summarizes the key points and information presented in the text.
423                               Your answer should be in your own words and be no longer than 50 words.
424                               \n\n Related text: {join(documents)} \n\n Question: {query} \n\n Answer:""",
425      output_parser=AnswerParser(),
426  )
427  
428  prompt_node = PromptNode(
429      model_name_or_path="gpt-3.5-turbo",
430      api_key=OPENAI_API_KEY,
431      default_prompt_template=rag_prompt,
432  )
433  
434  pipe = Pipeline()
435  pipe.add_node(component=retriever, name="retriever", inputs=["Query"])
436  pipe.add_node(component=prompt_node, name="prompt_node", inputs=["retriever"])
437  
438  output = pipe.run(query="What does Rhodes Statue look like?")
439  ```
440  
441  </details>
442  
443  <details>
444  
445  <summary>Haystack 2.x</summary>
446  
447  ```python
448  from datasets import load_dataset
449  
450  from haystack import Document, Pipeline
451  from haystack.document_stores.in_memory import InMemoryDocumentStore
452  from haystack.components.builders import PromptBuilder
453  from haystack.components.generators import OpenAIGenerator
454  from haystack.components.embedders import SentenceTransformersDocumentEmbedder
455  from haystack.components.embedders import SentenceTransformersTextEmbedder
456  from haystack.components.retrievers import InMemoryEmbeddingRetriever
457  
458  document_store = InMemoryDocumentStore()
459  dataset = load_dataset("bilgeyucel/seven-wonders", split="train")
460  embedder = SentenceTransformersDocumentEmbedder(
461      "sentence-transformers/all-MiniLM-L6-v2",
462  )
463  embedder.warm_up()
464  output = embedder.run([Document(**ds) for ds in dataset])
465  document_store.write_documents(output.get("documents"))
466  
467  template = """
468  Given the following information, answer the question.
469  
470  Context:
471  {% for document in documents %}
472      {{ document.content }}
473  {% endfor %}
474  
475  Question: {{question}}
476  Answer:
477  """
478  prompt_builder = PromptBuilder(template=template)
479  
480  retriever = InMemoryEmbeddingRetriever(document_store=document_store, top_k=2)
481  generator = OpenAIGenerator(model="gpt-3.5-turbo")
482  query_embedder = SentenceTransformersTextEmbedder(
483      model="sentence-transformers/all-MiniLM-L6-v2",
484  )
485  
486  basic_rag_pipeline = Pipeline()
487  basic_rag_pipeline.add_component("text_embedder", query_embedder)
488  basic_rag_pipeline.add_component("retriever", retriever)
489  basic_rag_pipeline.add_component("prompt_builder", prompt_builder)
490  basic_rag_pipeline.add_component("llm", generator)
491  
492  basic_rag_pipeline.connect("text_embedder.embedding", "retriever.query_embedding")
493  basic_rag_pipeline.connect("retriever", "prompt_builder.documents")
494  basic_rag_pipeline.connect("prompt_builder", "llm")
495  
496  query = "What does Rhodes Statue look like?"
497  output = basic_rag_pipeline.run(
498      {"text_embedder": {"text": query}, "prompt_builder": {"question": query}},
499  )
500  ```
501  
502  </details>
503  
504  ## Documentation and Tutorials for Haystack 1.x
505  
506  You can access old tutorials in the [GitHub history](https://github.com/deepset-ai/haystack-tutorials/tree/5917718cbfbb61410aab4121ee6fe754040a5dc7) and download the Haystack 1.x documentation as a [ZIP file](https://core-engineering.s3.eu-central-1.amazonaws.com/public/docs/haystack-v1-docs.zip).
507  
508  The ZIP file contains documentation for all minor releases from version 1.0 to 1.26.
509  
510  To download documentation for a specific release, replace the version number in the following URL: `https://core-engineering.s3.eu-central-1.amazonaws.com/public/docs/v1.26.zip`.