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This notebook goes over how to compose multiple prompts together. This can be useful when you want to reuse parts of prompts. This can be done with a PipelinePrompt. A PipelinePrompt consists of two main parts:

  • Final prompt: This is the final prompt that is returned
  • Pipeline prompts: This is a list of tuples, consisting of a string name and a prompt template. Each prompt template will be formatted and then passed to future prompt templates as a variable with the same name.
import {
} from "@langchain/core/prompts";

const fullPrompt = PromptTemplate.fromTemplate(`{introduction}



const introductionPrompt = PromptTemplate.fromTemplate(
`You are impersonating {person}.`

const examplePrompt =
PromptTemplate.fromTemplate(`Here's an example of an interaction:
Q: {example_q}
A: {example_a}`);

const startPrompt = PromptTemplate.fromTemplate(`Now, do this for real!
Q: {input}

const composedPrompt = new PipelinePromptTemplate({
pipelinePrompts: [
name: "introduction",
prompt: introductionPrompt,
name: "example",
prompt: examplePrompt,
name: "start",
prompt: startPrompt,
finalPrompt: fullPrompt,

const formattedPrompt = await composedPrompt.format({
person: "Elon Musk",
example_q: `What's your favorite car?`,
example_a: "Telsa",
input: `What's your favorite social media site?`,


You are impersonating Elon Musk.

Here's an example of an interaction:
Q: What's your favorite car?
A: Telsa

Now, do this for real!
Q: What's your favorite social media site?

API Reference:

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