Large Language Models

Integrating LLMs into structured NLP pipelines

The spacy-llm package integrates Large Language Models (LLMs) into spaCy pipelines, featuring a modular system for fast prototyping and prompting, and turning unstructured responses into robust outputs for various NLP tasks, no training data required.

  • Serializable llm component to integrate prompts into your pipeline
  • Modular functions to define the task (prompting and parsing) and model (model to use)
  • Support for hosted APIs and self-hosted open-source models
  • Integration with LangChain
  • Access to OpenAI API, including GPT-4 and various GPT-3 models
  • Built-in support for various open-source models hosted on Hugging Face
  • Usage examples for standard NLP tasks such as Named Entity Recognition and Text Classification
  • Easy implementation of your own functions via the registry for custom prompting, parsing and model integrations


Large Language Models (LLMs) feature powerful natural language understanding capabilities. With only a few (and sometimes no) examples, an LLM can be prompted to perform custom NLP tasks such as text categorization, named entity recognition, coreference resolution, information extraction and more.

Supervised learning is much worse than LLM prompting for prototyping, but for many tasks it’s much better for production. A transformer model that runs comfortably on a single GPU is extremely powerful, and it’s likely to be a better choice for any task for which you have a well-defined output. You train the model with anything from a few hundred to a few thousand labelled examples, and it will learn to do exactly that. Efficiency, reliability and control are all better with supervised learning, and accuracy will generally be higher than LLM prompting as well.

spacy-llm lets you have the best of both worlds. You can quickly initialize a pipeline with components powered by LLM prompts, and freely mix in components powered by other approaches. As your project progresses, you can look at replacing some or all of the LLM-powered components as you require.

Of course, there can be components in your system for which the power of an LLM is fully justified. If you want a system that can synthesize information from multiple documents in subtle ways and generate a nuanced summary for you, bigger is better. However, even if your production system needs an LLM for some of the task, that doesn’t mean you need an LLM for all of it. Maybe you want to use a cheap text classification model to help you find the texts to summarize, or maybe you want to add a rule-based system to sanity check the output of the summary. These before-and-after tasks are much easier with a mature and well-thought-out library, which is exactly what spaCy provides.


spacy-llm will be installed automatically in future spaCy versions. For now, you can run the following in the same virtual environment where you already have spacy installed.


The task and the model have to be supplied to the llm pipeline component using the config system. This package provides various built-in functionality, as detailed in the API documentation.

Example 1: Add a text classifier using a GPT-3 model from OpenAI

Create a new API key from or fetch an existing one, and ensure the keys are set as environmental variables. For more background information, see the OpenAI section.

Create a config file config.cfg containing at least the following (or see the full example here):

Now run:

Example 2: Add NER using an open-source model through Hugging Face

To run this example, ensure that you have a GPU enabled, and transformers, torch and CUDA installed. For more background information, see the DollyHF section.

Create a config file config.cfg containing at least the following (or see the full example here):

Now run:

Note that Hugging Face will download the "databricks/dolly-v2-3b" model the first time you use it. You can define the cached directory by setting the environmental variable HF_HOME. Also, you can upgrade the model to be "databricks/dolly-v2-12b" for better performance.

Example 3: Create the component directly in Python

The llm component behaves as any other component does, and there are task-specific components defined to help you hit the ground running with a reasonable built-in task implementation.

Note that for efficient usage of resources, typically you would use nlp.pipe(docs) with a batch, instead of calling nlp(doc) with a single document.

Example 4: Implement your own custom task

To write a task, you need to implement two functions: generate_prompts that takes a list of Doc objects and transforms them into a list of prompts, and parse_responses that transforms the LLM outputs into annotations on the Doc, e.g. entity spans, text categories and more.

To register your custom task, decorate a factory function using the spacy_llm.registry.llm_tasks decorator with a custom name that you can refer to in your config.


spacy-llm has a built-in logger that can log the prompt sent to the LLM as well as its raw response. This logger uses the debug level and by default has a logging.NullHandler() configured.

In order to use this logger, you can setup a simple handler like this:

Then when using the pipeline you’ll be able to view the prompt and response.

E.g. with the config and code from Example 1 above:

You will see logging output similar to:

print(doc.cats) to standard output should look like:


spacy-llm exposes an llm factory with configurable settings.

An llm component is defined by two main settings:

  • A task, defining the prompt to send to the LLM as well as the functionality to parse the resulting response back into structured fields on the Doc objects.
  • A model defining the model to use and how to connect to it. Note that spacy-llm supports both access to external APIs (such as OpenAI) as well as access to self-hosted open-source LLMs (such as using Dolly through Hugging Face).

Moreover, spacy-llm exposes a customizable caching functionality to avoid running the same document through an LLM service (be it local or through a REST API) more than once.

Finally, you can choose to save a stringified version of LLM prompts/responses within the Doc.user_data["llm_io"] attribute by setting save_io to True. Doc.user_data["llm_io"] is a dictionary containing one entry for every LLM component within the nlp pipeline. Each entry is itself a dictionary, with two keys: prompt and response.

A note on validate_types: by default, spacy-llm checks whether the signatures of the model and task callables are consistent with each other and emits a warning if they don’t. validate_types can be set to False if you want to disable this behavior.


A task defines an NLP problem or question, that will be sent to the LLM via a prompt. Further, the task defines how to parse the LLM’s responses back into structured information. All tasks are registered in the llm_tasks registry.

Practically speaking, a task should adhere to the Protocol LLMTask defined in It needs to define a generate_prompts function and a parse_responses function.

task.generate_promptsTakes a collection of documents, and returns a collection of “prompts”, which can be of type Any.
task.parse_responsesTakes a collection of LLM responses and the original documents, parses the responses into structured information, and sets the annotations on the documents.

Moreover, the task may define an optional scorer method. It should accept an iterable of Example objects as input and return a score dictionary. If the scorer method is defined, spacy-llm will call it to evaluate the component.

spacy.Summarization.v1The summarization task prompts the model for a concise summary of the provided text.
spacy.NER.v3Implements Chain-of-Thought reasoning for NER extraction - obtains higher accuracy than v1 or v2.
spacy.NER.v2Builds on v1 and additionally supports defining the provided labels with explicit descriptions.
spacy.NER.v1The original version of the built-in NER task supports both zero-shot and few-shot prompting.
spacy.SpanCat.v3Adaptation of the v3 NER task to support overlapping entities and store its annotations in doc.spans.
spacy.SpanCat.v2Adaptation of the v2 NER task to support overlapping entities and store its annotations in doc.spans.
spacy.SpanCat.v1Adaptation of the v1 NER task to support overlapping entities and store its annotations in doc.spans.
spacy.REL.v1Relation Extraction task supporting both zero-shot and few-shot prompting.
spacy.TextCat.v3Version 3 builds on v2 and allows setting definitions of labels.
spacy.TextCat.v2Version 2 builds on v1 and includes an improved prompt template.
spacy.TextCat.v1Version 1 of the built-in TextCat task supports both zero-shot and few-shot prompting.
spacy.Lemma.v1Lemmatizes the provided text and updates the lemma_ attribute of the tokens accordingly.
spacy.Sentiment.v1Performs sentiment analysis on provided texts.
spacy.NoOp.v1This task is only useful for testing - it tells the LLM to do nothing, and does not set any fields on the docs.

Providing examples for few-shot prompts

All built-in tasks support few-shot prompts, i. e. including examples in a prompt. Examples can be supplied in two ways: (1) as a separate file containing only examples or (2) by initializing llm with a get_examples() callback (like any other pipeline component).

(1) Few-shot example file

A file containing examples for few-shot prompting can be configured like this:

The supplied file has to conform to the format expected by the required task (see the task documentation further down).

(2) Initializing the llm component with a get_examples() callback

Alternatively, you can initialize your nlp pipeline by providing a get_examples callback for nlp.initialize and setting n_prompt_examples to a positive number to automatically fetch a few examples for few-shot learning. Set n_prompt_examples to -1 to use all examples as part of the few-shot learning prompt.


A model defines which LLM model to query, and how to query it. It can be a simple function taking a collection of prompts (consistent with the output type of task.generate_prompts()) and returning a collection of responses (consistent with the expected input of parse_responses). Generally speaking, it’s a function of type Callable[[Iterable[Any]], Iterable[Any]], but specific implementations can have other signatures, like Callable[[Iterable[str]], Iterable[str]].

All built-in models are registered in llm_models. If no model is specified, the repo currently connects to the OpenAI API by default using REST, and accesses the "gpt-3.5-turbo" model.

Currently three different approaches to use LLMs are supported:

  1. spacy-llms native REST interface. This is the default for all hosted models (e. g. OpenAI, Cohere, Anthropic, …).
  2. A HuggingFace integration that allows to run a limited set of HF models locally.
  3. A LangChain integration that allows to run any model supported by LangChain (hosted or locally).

Approaches 1. and 2 are the default for hosted model and local models, respectively. Alternatively you can use LangChain to access hosted or local models by specifying one of the models registered with the langchain. prefix.

spacy.GPT-4.v2OpenAI’s gpt-4 model family.
spacy.GPT-3-5.v2OpenAI’s gpt-3-5 model family.
spacy.Text-Davinci.v2OpenAI’s text-davinci model family.
spacy.Code-Davinci.v2OpenAI’s code-davinci model family.
spacy.Text-Curie.v2OpenAI’s text-curie model family.
spacy.Text-Babbage.v2OpenAI’s text-babbage model family.
spacy.Text-Ada.v2OpenAI’s text-ada model family.
spacy.Davinci.v2OpenAI’s davinci model family.
spacy.Curie.v2OpenAI’s curie model family.
spacy.Babbage.v2OpenAI’s babbage model family.
spacy.Ada.v2OpenAI’s ada model family.
spacy.Command.v1Cohere’s command model family.
spacy.Claude-2.v1Anthropic’s claude-2 model family.
spacy.Claude-1.v1Anthropic’s claude-1 model family.
spacy.Claude-instant-1.v1Anthropic’s claude-instant-1 model family.
spacy.Claude-instant-1-1.v1Anthropic’s claude-instant-1.1 model family.
spacy.Claude-1-0.v1Anthropic’s claude-1.0 model family.
spacy.Claude-1-2.v1Anthropic’s claude-1.2 model family.
spacy.Claude-1-3.v1Anthropic’s claude-1.3 model family.
spacy.Dolly.v1Dolly models through HuggingFace.
spacy.Falcon.v1Falcon models through HuggingFace.
spacy.Llama2.v1Llama2 models through HuggingFace.
spacy.StableLM.v1StableLM models through HuggingFace.
spacy.OpenLLaMA.v1OpenLLaMA models through HuggingFace.
LangChain modelsLangChain models for API retrieval.

Note that the chat models variants of Llama 2 are currently not supported. This is because they need a particular prompting setup and don’t add any discernible benefits in the use case of spacy-llm (i. e. no interactive chat) compared to the completion model variants.


Interacting with LLMs, either through an external API or a local instance, is costly. Since developing an NLP pipeline generally means a lot of exploration and prototyping, spacy-llm implements a built-in cache to avoid reprocessing the same documents at each run that keeps batches of documents stored on disk.

Various functions

spacy.FewShotReader.v1This function is registered in spaCy’s misc registry, and reads in examples from a .yml, .yaml, .json or .jsonl file. It uses srsly to read in these files and parses them depending on the file extension.
spacy.FileReader.v1This function is registered in spaCy’s misc registry, and reads a file provided to the path to return a str representation of its contents. This function is typically used to read Jinja files containing the prompt template.
Normalizer functionsThese functions provide simple normalizations for string comparisons, e.g. between a list of specified labels and a label given in the raw text of the LLM response.