ExternalGenerator

Call an external service with a prompt and return its response.

ExternalGenerator sends a prompt to an external service and returns the results from the service. It expects the service to respond with answer: str, meta: Dict. It acts just like any other Generator except that instead of calling an LLM, it calls an external service.

ExternalGenerator is flexible regarding what constitutes a prompt and what the external service does with it. For example, this component can send a SQL query as a prompt to be run on a database in an external service.

Key Features

• Sends a text prompt to any external HTTP service and returns the response.
• Compatible with PromptBuilder for receiving prompts and with DeepsetAnswerBuilder for building answers with references.
• Configurable timeout for requests.
• Flexible: works with any service that accepts a string prompt and returns a string answer.

Configuration

1. Drag the ExternalGenerator component onto the canvas from the Component Library.
2. Click on the component to open the configuration panel.
3. On the General tab:
   1. Enter the URL of the external service to post the prompt to.
4. Go to the Advanced tab to configure the timeout for requests (default: 50 seconds).

Connections

ExternalGenerator receives the prompt from PromptBuilder through its prompt input. It outputs the responses from the service as a list of strings through its replies output, which you connect to DeepsetAnswerBuilder.

Usage Examples

Basic Configuration

  ExternalGenerator:
    type: deepset_cloud_custom_nodes.generators.external.ExternalGenerator
    init_parameters:
      url: https://your-service.example.com/generate

Using the Component in a Pipeline

This query pipeline sends a prompt to an external HTTP service and builds an answer from the response:

# haystack-pipeline
components:
  prompt_builder:
    type: haystack.components.builders.prompt_builder.PromptBuilder
    init_parameters:
      template: "Answer the question: {{ query }}"
      required_variables:
      - query

  external_generator:
    type: deepset_cloud_custom_nodes.generators.external.ExternalGenerator
    init_parameters:
      url: https://your-service.example.com/generate
      timeout: 50

  answer_builder:
    type: haystack.components.builders.answer_builder.AnswerBuilder
    init_parameters: {}

connections:
- sender: prompt_builder.prompt
  receiver: external_generator.prompt
- sender: external_generator.replies
  receiver: answer_builder.replies

inputs:
  query:
  - prompt_builder.query
  - answer_builder.query

outputs:
  answers: answer_builder.answers

max_runs_per_component: 100

metadata: {}

Parameters

Inputs

Parameter	Type	Description
prompt	str	The prompt to pass to the service.
meta	Optional[Dict]	Additional metadata related to the prompt.

Outputs

Parameter	Type	Description
replies	List[str]	The answers from the service.
meta	List[Dict[str, Any]]	Metadata related to the answers.

Init Parameters

These are the parameters you can configure in Pipeline Builder:

Parameter	Type	Default	Description
url	str		The URL of the external service to post the prompt to.
timeout	int	50	The timeout for requests sent to the URL.

Run Method Parameters

These are the parameters you can configure for the component's run() method. This means you can pass these parameters at query time through the API, in Playground, or when running a job. For details, see Modify Pipeline Parameters at Query Time.

Parameter	Type	Default	Description
prompt	str		The prompt to pass to the service.
meta	Optional[Dict]	None	Additional metadata related to the prompt.