Prompts with Templates

Handlebars is used as a template engine when generating the prompt, so you can take advantage of advanced template features in the prompt. See full capabilities here.

Below is a simple example showing syntax for replacing simple variables in the template.

const prompt = createChatPrompt("Your name is {{agentName}}");
const formatted = prompt.format({ agentName: "Greg" });

[
  {
    "role": "system",
    "content": "Your name is Greg"
  }
]

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Here is a more advanced example showing a template that uses the if and each helpers supplied by Handlebars.

  const prompt = createChatPrompt("Your name is {{agentName}}");

  const template = `{{#if fruits.length}}
Ask about one of these fruits:
{{#each fruits as | fruit |}}
- {{fruit}}
{{/each}}
{{/if}}`;

  prompt.addSystemMessage(template);

  const formatted = prompt.format({
    agentName: "Greg",
    fruits: ["apple", "banana"],
  });

[
  {
    "role": "system",
    "content": "Your name is Greg"
  },
  {
    "role": "system",
    "content": "Ask about one of these fruits:\n- apple\n- banana\n"
  }
]

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Below is a robust example showing multiple variables, and defining types.

  interface PromptTemplate {
    actions: {
      name: string;
      description: string;
    }[];
    previousSteps: {
      thought: string;
      action: string;
      result: string;
    }[];
  }

  const template = `You are an agent that can only perform the following actions:

# Actions
{{#each actions as | action |}}
{{ action.name }} ({{ action.description }})
{{/each}}

# Previous Steps Taken
{{#each previousSteps as | previousStep |}}
Thought: {{previousStep.thought}}
Action: {{previousStep.action}}
{{/each}}`;

  const instruction = `What step should we take? Must be one of: {{#each actions as | action |}}, {{ action.name }}{{/each}}.`;

  // some data from state or your application
  const history: IChatMessages = [
    { role: "user", content: "Hey!" },
    { role: "assistant", content: "Hi, how are you?" },
    { role: "user", content: "Good. What day is it?" },
  ];

  const actions = [
    { name: "say_hi", description: "Provide an initial greeting." },
    {
      name: "say_bye",
      description: "Say goodbye at the end of a conversation.",
    },
    { name: "ask_question", description: "Ask the user a question." },
    { name: "provide_answer", description: "Provide an answer to a question" },
  ];

  const previousSteps = [
    {
      thought: "I should say hi",
      action: "say_hi",
      result: "Hi, how are you?",
    },
  ];

  const prompt = createChatPrompt<PromptTemplate>(template)
    .addFromHistory(history)
    .addSystemMessage(instruction);

  // prompt.format is well-typed based on the generic you passed into createChatPrompt
  const formatted = prompt.format({ actions, previousSteps });

[
  {
    "role": "system",
    "content": "You are an agent that can only perform the following actions:\n\n# Actions\nsay_hi (Provide an initial greeting.)\nsay_bye (Say goodbye at the end of a conversation.)\nask_question (Ask the user a question.)\nprovide_answer (Provide an answer to a question)\n\n# Previous Steps Taken\nThought: I should say hi\nAction: say_hi\n"
  },
  {
    "role": "user",
    "content": "Hey!"
  },
  {
    "role": "assistant",
    "content": "Hi, how are you?"
  },
  {
    "role": "user",
    "content": "Good. What day is it?"
  },
  {
    "role": "system",
    "content": "What step should we take? Must be one of: , say_hi, say_bye, ask_question, provide_answer."
  }
]

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Prompt Template Default Helpers

Prompts are powered by handlebars, and you are able to register your own custom helpers, adding super powers to your prompt templates. Some core helpers are included by default.

• pluralize
• eq
• neq
• ifCond

Prompt Template Default Partials

Some core partials are included by default:

MarkdownCode

Raw Template

{{> MarkdownCode code='const name="Greg";' language='typescript' }}

Parsed

'''typescript
const name="Greg";
'''

DialogueHistory

Raw Template

// Basic example
{{> DialogueHistory key='keyOfTheChatHistory' }}

//  With title
{{> DialogueHistory title='The conversation is below:' key='keyOfTheChatHistory' }}

// Setting user name
{{> DialogueHistory key='keyOfTheChatHistory' user='Greg' }}

// Setting user and assistant - be creative!
{{> DialogueHistory key='keyOfTheChatHistory' assistant='Thought' user='Observation' }}


// Assuming you passed the following:
{
  keyOfTheChatHistory: [{
    role: "user",
    content: "Hello?",
  },{
    role: "user",
    content: "Hi! How can I help you?",
  },{
    role: "user",
    content: "I was wondering if you were open",
  },{
    role: "user",
    content: "We sure are!",
  }]
}

Parsed

// Basic example
User: Hello?
Assistant: Hi! How can I help you?
User: I was wondering if you were open
Assistant: We sure are!

//  With title
The conversation is below:
User: Hello?
Assistant: Hi! How can I help you?
User: I was wondering if you were open
Assistant: We sure are!

// Setting user name
Greg: Hello?
Assistant: Hi! How can I help you?
Greg: I was wondering if you were open
Assistant: We sure are!

// Setting user and assistant - be creative!
Thought: Hello?
Observation: Hi! How can I help you?
Thought: I was wondering if you were open
Observation: We sure are!

Template Custom Partials & Helpers

You can load custom Handlebars partials and helpers a few different ways:

1. Pass them in when initializing the prompt

// these could be managed elsewhere and imported here
const helpers = [
  {
    handler: (date: Date) => "morning",
    name: "getTimeOfDay",
  },
];

const partials = [
  {
    template: `Phone: 1-800-000-0000
Support Email: support@example.com
Website: www.example.com`,
    name: "partialContactInformation",
  },
];

// pass in `{ helpers, partials }` when creating prompt.
const prompt = createPrompt("text", "You are a cowboy.", { helpers, partials });