Prompts¶

When working with Large Language Model (LLM) APIs, the "prompt" is generally a list of messages where each message has a particular role. These prompts are the foundation of effectively working with LLMs, so Mirascope provides powerful tools to help you create, manage, and optimize your prompts for various LLM interactions.

Let's look at how we can write prompts using Mirascope in a reusable, modular, and provider-agnostic way.

Calls will come later

For the following explanations we will be talking only about the messages aspect of prompt engineering and will discuss calling the API later in the Calls documentation.

In that section we will show how to use these provider-agnostic prompts to actually call a provider's API as well as how to engineer and tie a prompt to a specific call.

Prompt Templates (Messages)¶

API Documentation

mirascope.core.base.message_param

mirascope.core.base.prompt.prompt_template

First, let's look at a basic example:

ShorthandMessagesString TemplateBaseMessageParam

from mirascope.core import prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> str:
    return f"Recommend a {genre} book"


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book')]

from mirascope.core import Messages, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> Messages.Type:
    return Messages.User(f"Recommend a {genre} book")


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book')]

from mirascope.core import prompt_template


@prompt_template("Recommend a {genre} book")
def recommend_book_prompt(genre: str): ...


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book')]

from mirascope.core import BaseMessageParam, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> list[BaseMessageParam]:
    return [BaseMessageParam(role="user", content=f"Recommend a {genre} book")]


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book')]

In this example:

The recommend_book_prompt method's signature defines the prompt's template variables.
Calling the method with genre="fantasy" returns a list with the corresponding BaseMessageParam instance with role user and content "Recommend a fantasy book".

The core concept to understand here is BaseMessageParam. This class operates as the base class for message parameters that Mirascope can handle and use across all supported providers.

In Mirascope, we use the @prompt_template decorator to write prompt templates as reusable methods that return the corresponding list of BaseMessageParam instances.

There are four methods of writing prompts:

(Shorthand) Returning the str or list content for a single user message.
(Messages) Using Messages.{Role} methods, which accept the full or shorthand content and output a BaseMessageParam instance.
(String Template) Passing a string template to @prompt_template that gets parsed and then formatted like a normal Python formatted string.
(BaseMessageParam) Directly writing BaseMessageParam instances.

Which method you use is mostly up to your preference, so feel free to select which one you prefer in the following sections.

Message Roles¶

We can also define additional messages with different roles, such as a system message:

ShorthandMessagesString TemplateBaseMessageParam

from mirascope.core import Messages, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> Messages.Type:
    return [
        Messages.System("You are a librarian"),
        Messages.User(f"Recommend a {genre} book"),
    ]


print(recommend_book_prompt("fantasy"))
# Output: [
#   BaseMessageParam(role='system', content='You are a librarian'),
#   BaseMessageParam(role='user', content='Recommend a fantasy book'),
# ]

from mirascope.core import Messages, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> Messages.Type:
    return [
        Messages.System("You are a librarian"),
        Messages.User(f"Recommend a {genre} book"),
    ]


print(recommend_book_prompt("fantasy"))
# Output: [
#   BaseMessageParam(role='system', content='You are a librarian'),
#   BaseMessageParam(role='user', content='Recommend a fantasy book'),
# ]

from mirascope.core import prompt_template


@prompt_template(
    """
    SYSTEM: You are a librarian
    USER: Recommend a {genre} book
    """
)
def recommend_book_prompt(genre: str): ...


print(recommend_book_prompt("fantasy"))
# Output: [
#   BaseMessageParam(role='system', content='You are a librarian'),
#   BaseMessageParam(role='user', content='Recommend a fantasy book'),
# ]

from mirascope.core import BaseMessageParam, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> list[BaseMessageParam]:
    return [
        BaseMessageParam(role="system", content="You are a librarian"),
        BaseMessageParam(role="user", content=f"Recommend a {genre} book"),
    ]


print(recommend_book_prompt("fantasy"))
# Output: [
#   BaseMessageParam(role='system', content='You are a librarian'),
#   BaseMessageParam(role='user', content='Recommend a fantasy book'),
# ]

Messages.Type

The return type Messages.Type accepts all shorthand methods as well as BaseMessageParam types. Since the message methods (e.g. Messages.User) return BaseMessageParam instances, we generally recommend always typing your prompt templates with the Messages.Type return type since it covers all prompt template writing methods.

Supported Roles

Mirascope prompt templates currently support the system, user, and assistant roles. When using string templates, the roles are parsed by their corresponding all caps keyword (e.g. SYSTEM).

For messages with the tool role, see how Mirascope automatically generates these messages for you in the Tools and Agents sections.

Multi-Line Prompts¶

When writing prompts that span multiple lines, it's important to ensure you don't accidentally include additional, unnecessary tokens (namely \t tokens):

ShorthandMessagesString TemplateBaseMessageParam

import inspect

from mirascope.core import Messages, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> Messages.Type:
    return inspect.cleandoc(
        f"""
        Recommend a {genre} book.
        Output in the format Title by Author.
        """
    )


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='system', content='Recommend a fantasy book.\nOutput in the format Title by Author.')]

import inspect

from mirascope.core import Messages, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> Messages.Type:
    return Messages.User(
        inspect.cleandoc(
            f"""
            Recommend a {genre} book.
            Output in the format Title by Author.
            """
        )
    )


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='system', content='Recommend a fantasy book.\nOutput in the format Title by Author.')]

from mirascope.core import prompt_template


@prompt_template(
    """
    Recommend a {genre} book.
    Output in the format Title by Author.
    """
)
def recommend_book_prompt(genre: str): ...


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='system', content='Recommend a fantasy book.\nOutput in the format Title by Author.')]

import inspect

from mirascope.core import BaseMessageParam, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> list[BaseMessageParam]:
    return [
        BaseMessageParam(
            role="user",
            content=inspect.cleandoc(
                f"""
                Recommend a {genre} book.
                Output in the format Title by Author.
                """
            ),
        ),
    ]


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='system', content='Recommend a fantasy book.\nOutput in the format Title by Author.')]

In this example, we use inspect.cleandoc to remove unnecessary tokens while maintaining proper formatting in our codebase.

Multi-Line String Templates

When using string templates, the template is automatically cleaned for you, so there is no need to use inspect.cleandoc in that case. However, it's extremely important to note that you must start messages with the same indentation in order to properly remove the unnecessary tokens. For example:

# BAD
@prompt_template(
    """
    USER: First line
    Second line
    """
)

# GOOD
@prompt_template(
    """
    USER:
    First line
    Second line
    """
)

Recent advancements in Large Language Model architecture has enabled many model providers to support multi-modal inputs (text, images, audio, etc.) for a single endpoint. Mirascope treats these input types as first-class and supports them natively.

While Mirascope provides a consistent interface, support varies among providers:

Type	Anthropic	Cohere	Gemini	Groq	Mistral	OpenAI
text	✓	✓	✓	✓	✓	✓
image	✓	-	✓	✓	✓	✓
audio	-	-	✓	-	-	-
video	-	-	✓	-	-	-

Legend: ✓ (Supported), - (Not Supported)

Image Inputs¶

ShorthandMessagesString TemplateBaseMessageParam

from mirascope.core import Messages, prompt_template
from PIL import Image


@prompt_template()
def recommend_book_prompt(previous_book: Image.Image) -> Messages.Type:
    return ["I just read this book:", previous_book, "What should I read next?"]


with Image.open("...") as image:
    print(recommend_book_prompt(image))
# Output: [
#     BaseMessageParam(
#         role="user",
#         content=[
#             TextPart(type="text", text="I just read this book:"),
#             ImagePart(type="image", media_type="image/jpeg", image=b"...", detail=None),
#             TextPart(type="text", text="What should I read next?"),
#         ],
#     )
# ]

from mirascope.core import Messages, prompt_template
from PIL import Image


@prompt_template()
def recommend_book_prompt(previous_book: Image.Image) -> Messages.Type:
    return Messages.User(
        ["I just read this book:", previous_book, "What should I read next?"]
    )


with Image.open("...") as image:
    print(recommend_book_prompt(image))
# Output: [
#     BaseMessageParam(
#         role="user",
#         content=[
#             TextPart(type="text", text="I just read this book:"),
#             ImagePart(type="image", media_type="image/jpeg", image=b"...", detail=None),
#             TextPart(type="text", text="What should I read next?"),
#         ],
#     )
# ]

from mirascope.core import prompt_template


@prompt_template(
    "I just read this book: {previous_book:image} What should I read next?"
)
def recommend_book_prompt(previous_book: bytes): ...


print(recommend_book_prompt(b"..."))
# Output: [
#     BaseMessageParam(
#         role="user",
#         content=[
#             TextPart(type="text", text="I just read this book:"),
#             ImagePart(type="image", media_type="image/jpeg", image=b"...", detail=None),
#             TextPart(type="text", text="What should I read next?"),
#         ],
#     )
# ]

from mirascope.core import BaseMessageParam
from mirascope.core.base import ImagePart, TextPart


def recommend_book_prompt(previous_book_jpeg: bytes) -> list[BaseMessageParam]:
    return [
        BaseMessageParam(
            role="user",
            content=[
                TextPart(type="text", text="I just read this book:"),
                ImagePart(
                    type="image",
                    media_type="image/jpeg",
                    image=previous_book_jpeg,
                    detail=None,
                ),
                TextPart(type="text", text="What should I read next?"),
            ],
        )
    ]


print(recommend_book_prompt(b"..."))
# Output: [
#     BaseMessageParam(
#         role="user",
#         content=[
#             TextPart(type="text", text="I just read this book:"),
#             ImagePart(type="image", media_type="image/jpeg", image=b"...", detail=None),
#             TextPart(type="text", text="What should I read next?"),
#         ],
#     )
# ]

Additional String Template Image Functionality

When using string templates, you can also specify :images to inject multiple image inputs through a single template variable.

The :image and :images tags support the bytes | str and list[bytes] | list[str] types, respectively. When passing in a str, the string template assumes it indicates a url or local filepath and will attempt to load the bytes from the source.

You can also specify additional options as arguments of the tags, e.g. {url:image(detail=low)}

Audio Inputs¶

ShorthandMessagesString TemplateBaseMessageParam

# Coming soon...

# Coming soon...

from mirascope.core import prompt_template


@prompt_template("Here's an audio book snippet: {mp3:audio} What book is this?")
def identify_book_prompt(audio_mp3: bytes): ...


print(identify_book_prompt(b"..."))
# Output: [
#     BaseMessageParam(
#         role="user",
#         content=[
#             TextPart(type="text", text="Here's an audio book snippet:"),
#             ImagePart(type="image", media_type="image/jpeg", image=b"...", detail=None),
#             TextPart(type="text", text="What book is this?"),
#         ],
#     )
# ]

from mirascope.core import BaseMessageParam
from mirascope.core.base import AudioPart, TextPart


def identify_book_prompt(audio_mp3: bytes) -> list[BaseMessageParam]:
    return [
        BaseMessageParam(
            role="user",
            content=[
                TextPart(type="text", text="Here's an audio book snippet:"),
                AudioPart(
                    type="audio",
                    media_type="audio/mp3",
                    audio=audio_mp3,
                ),
                TextPart(type="text", text="What book is this?"),
            ],
        )
    ]


print(identify_book_prompt(b"..."))
# Output: [
#     BaseMessageParam(
#         role="user",
#         content=[
#             TextPart(type="text", text="Here's an audio book snippet:"),
#             ImagePart(type="image", media_type="image/jpeg", image=b"...", detail=None),
#             TextPart(type="text", text="What book is this?"),
#         ],
#     )
# ]

Additional String Template Audio Functionality

When using string templates, you can also specify :audios to inject multiple audio inputs through a single template variable.

The :audio and :audios tags support the bytes | str and list[bytes] | list[str] types, respectively. When passing in a str, the string template assumes it indicates a url or local filepath and will attempt to load the bytes from the source.

Chat History¶

Often you'll want to inject messages (such as previous chat messages) into the prompt. Generally you can just unroll the messages into the return value of your prompt template. When using string templates, we provide a MESSAGES keyword for this injection, which you can add in whatever position and as many times as you'd like:

ShorthandMessagesString TemplateBaseMessageParam

from mirascope.core import BaseMessageParam, Messages, prompt_template


@prompt_template()
def chatbot(query: str, history: list[BaseMessageParam]) -> list[BaseMessageParam]:
    return [Messages.System("You are a librarian"), *history, Messages.User(query)]


history = [
    Messages.User("Recommend a book"),
    Messages.Assistant("What genre do you like?"),
]
print(chatbot("fantasy", history))
# Output: [
#     BaseMessageParam(role="system", content="You are a librarian"),
#     BaseMessageParam(role="user", content="Recommend a book"),
#     BaseMessageParam(role="assistant", content="What genre do you like?"),
#     BaseMessageParam(role="user", content="fantasy"),
# ]

from mirascope.core import BaseMessageParam, Messages, prompt_template


@prompt_template()
def chatbot(query: str, history: list[BaseMessageParam]) -> list[BaseMessageParam]:
    return [Messages.System("You are a librarian"), *history, Messages.User(query)]


history = [
    Messages.User("Recommend a book"),
    Messages.Assistant("What genre do you like?"),
]
print(chatbot("fantasy", history))
# Output: [
#     BaseMessageParam(role="system", content="You are a librarian"),
#     BaseMessageParam(role="user", content="Recommend a book"),
#     BaseMessageParam(role="assistant", content="What genre do you like?"),
#     BaseMessageParam(role="user", content="fantasy"),
# ]

from mirascope.core import BaseMessageParam, Messages, prompt_template


@prompt_template(
    """
    SYSTEM: You are a librarian
    MESSAGES: {history}
    USER: {query}
    """
)
def chatbot(query: str, history: list[BaseMessageParam]): ...


history = [
    Messages.User("Recommend a book"),
    Messages.Assistant("What genre do you like?"),
]
print(chatbot("fantasy", history))
# Output: [
#     BaseMessageParam(role="system", content="You are a librarian"),
#     BaseMessageParam(role="user", content="Recommend a book"),
#     BaseMessageParam(role="assistant", content="What genre do you like?"),
#     BaseMessageParam(role="user", content="fantasy"),
# ]

from mirascope.core import BaseMessageParam, prompt_template


@prompt_template()
def chatbot(query: str, history: list[BaseMessageParam]) -> list[BaseMessageParam]:
    return [
        BaseMessageParam(role="system", content="You are a librarian"),
        *history,
        BaseMessageParam(role="user", content=query),
    ]


history = [
    BaseMessageParam(role="user", content="Recommend a book"),
    BaseMessageParam(role="assistant", content="What genre do you like?"),
]
print(chatbot("fantasy", history))
# Output: [
#     BaseMessageParam(role="system", content="You are a librarian"),
#     BaseMessageParam(role="user", content="Recommend a book"),
#     BaseMessageParam(role="assistant", content="What genre do you like?"),
#     BaseMessageParam(role="user", content="fantasy"),
# ]

Object Attribute Access¶

When using template variables that have attributes, you can easily inject these attributes directly even when using string templates:

ShorthandMessagesString TemplateBaseMessageParam

from mirascope.core import prompt_template
from pydantic import BaseModel


class Book(BaseModel):
    title: str
    author: str


@prompt_template()
def recommend_book_prompt(book: Book) -> str:
    return f"I read {book.title} by {book.author}. What should I read next?"


book = Book(title="The Name of the Wind", author="Patrick Rothfuss")
print(recommend_book_prompt(book))
# Output: [BaseMessageParam(role='user', content='I read The Name of the Wind by Patrick Rothfuss. What should I read next?')]

from mirascope.core import Messages, prompt_template
from pydantic import BaseModel


class Book(BaseModel):
    title: str
    author: str


@prompt_template()
def recommend_book_prompt(book: Book) -> Messages.Type:
    return Messages.User(
        f"I read {book.title} by {book.author}. What should I read next?"
    )


book = Book(title="The Name of the Wind", author="Patrick Rothfuss")
print(recommend_book_prompt(book))
# Output: [BaseMessageParam(role='user', content='I read The Name of the Wind by Patrick Rothfuss. What should I read next?')]

from mirascope.core import prompt_template
from pydantic import BaseModel


class Book(BaseModel):
    title: str
    author: str


@prompt_template("I read {book.title} by {book.author}. What should I read next?")
def recommend_book_prompt(book: Book): ...


book = Book(title="The Name of the Wind", author="Patrick Rothfuss")
print(recommend_book_prompt(book))
# Output: [BaseMessageParam(role='user', content='I read The Name of the Wind by Patrick Rothfuss. What should I read next?')]

from mirascope.core import BaseMessageParam, prompt_template
from pydantic import BaseModel


class Book(BaseModel):
    title: str
    author: str


@prompt_template()
def recommend_book_prompt(book: Book) -> list[BaseMessageParam]:
    return [
        BaseMessageParam(
            role="user",
            content=f"I read {book.title} by {book.author}. What should I read next?",
        )
    ]


book = Book(title="The Name of the Wind", author="Patrick Rothfuss")
print(recommend_book_prompt(book))
# Output: [BaseMessageParam(role='user', content='I read The Name of the Wind by Patrick Rothfuss. What should I read next?')]

It's worth noting that this also works with self when using prompt templates inside of a class, which is particularly important when building Agents.

Format Specifiers¶

Since Mirascope prompt templates are just formatted strings, standard Python format specifiers work as expected:

ShorthandMessagesString TemplateBaseMessageParam

from mirascope.core import prompt_template


@prompt_template()
def recommend_book(genre: str, price: float) -> str:
    return f"Recommend a {genre} book under ${price:.2f}"


print(recommend_book("fantasy", 12.3456))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book under $12.35')]

from mirascope.core import Messages, prompt_template


@prompt_template()
def recommend_book(genre: str, price: float) -> Messages.Type:
    return Messages.User(f"Recommend a {genre} book under ${price:.2f}")


print(recommend_book("fantasy", 12.3456))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book under $12.35')]

from mirascope.core import prompt_template


@prompt_template("Recommend a {genre} book under ${price:.2f}")
def recommend_book(genre: str, price: float): ...


print(recommend_book("fantasy", 12.3456))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book under $12.35')]

from mirascope.core import BaseMessageParam, prompt_template


@prompt_template()
def recommend_book(genre: str, price: float) -> list[BaseMessageParam]:
    return [
        BaseMessageParam(
            role="user", content=f"Recommend a {genre} book under ${price:.2f}"
        )
    ]


print(recommend_book("fantasy", 12.3456))
# Output: [BaseMessageParam(role='user', content='Recommend a fantasy book under $12.35')]

When writing string templates, we also offer additional list and lists format specifiers for convenience around formatting lists:

ShorthandMessagesString TemplateBaseMessageParam

import inspect

from mirascope.core import prompt_template


@prompt_template()
def recommend_book_prompt(genres: list[str], examples: list[list[str]]) -> str:
    formatted_genres = "\n".join(genres)
    formatted_examples = "\n\n".join(["\n".join(e) for e in examples])
    return inspect.cleandoc(
        """
        Recommend a book from one of the following genres:
        {genres}

        Examples:
        {examples}
        """
    ).format(genres=formatted_genres, examples=formatted_examples)


prompt = recommend_book_prompt(
    genres=["fantasy", "scifi", "mystery"],
    examples=[
        ["Title: The Name of the Wind", "Author: Patrick Rothfuss"],
        ["Title: Mistborn: The Final Empire", "Author: Brandon Sanderson"],
    ],
)
print(prompt)
# Output: [
#     BaseMessageParam(
#         role="user",
#         content="Recommend a book from one of the following genres:\nfantasy\nscifi\nmystery\n\nExamples:\nTitle: The Name of the Wind\nAuthor: Patrick Rothfuss\n\nTitle: Mistborn: The Final Empire\nAuthor: Brandon Sanderson",
#     )
# ]

print(prompt[0].content)
# Output:
# Recommend a book from one of the following genres:
# fantasy
# scifi
# mystery

# Examples:
# Title: The Name of the Wind
# Author: Patrick Rothfuss

# Title: Mistborn: The Final Empire
# Author: Brandon Sanderson

import inspect

from mirascope.core import Messages, prompt_template


@prompt_template()
def recommend_book_prompt(
    genres: list[str], examples: list[list[str]]
) -> Messages.Type:
    formatted_genres = "\n".join(genres)
    formatted_examples = "\n\n".join(["\n".join(e) for e in examples])
    return Messages.User(
        inspect.cleandoc(
            """
            Recommend a book from one of the following genres:
            {genres}

            Examples:
            {examples}
            """
        ).format(genres=formatted_genres, examples=formatted_examples)
    )


prompt = recommend_book_prompt(
    genres=["fantasy", "scifi", "mystery"],
    examples=[
        ["Title: The Name of the Wind", "Author: Patrick Rothfuss"],
        ["Title: Mistborn: The Final Empire", "Author: Brandon Sanderson"],
    ],
)
print(prompt)
# Output: [
#     BaseMessageParam(
#         role="user",
#         content="Recommend a book from one of the following genres:\nfantasy\nscifi\nmystery\n\nExamples:\nTitle: The Name of the Wind\nAuthor: Patrick Rothfuss\n\nTitle: Mistborn: The Final Empire\nAuthor: Brandon Sanderson",
#     )
# ]

print(prompt[0].content)
# Output:
# Recommend a book from one of the following genres:
# fantasy
# scifi
# mystery

# Examples:
# Title: The Name of the Wind
# Author: Patrick Rothfuss

# Title: Mistborn: The Final Empire
# Author: Brandon Sanderson

from mirascope.core import prompt_template


@prompt_template(
    """
    Recommend a book from one of the following genres:
    {genres:list}

    Examples:
    {examples:lists}
    """
)
def recommend_book_prompt(genres: list[str], examples: list[list[str]]): ...


prompt = recommend_book_prompt(
    genres=["fantasy", "scifi", "mystery"],
    examples=[
        ["Title: The Name of the Wind", "Author: Patrick Rothfuss"],
        ["Title: Mistborn: The Final Empire", "Author: Brandon Sanderson"],
    ],
)
print(prompt)
# Output: [
#     BaseMessageParam(
#         role="user",
#         content="Recommend a book from one of the following genres:\nfantasy\nscifi\nmystery\n\nExamples:\nTitle: The Name of the Wind\nAuthor: Patrick Rothfuss\n\nTitle: Mistborn: The Final Empire\nAuthor: Brandon Sanderson",
#     )
# ]

print(prompt[0].content)
# Output:
# Recommend a book from one of the following genres:
# fantasy
# scifi
# mystery

# Examples:
# Title: The Name of the Wind
# Author: Patrick Rothfuss

# Title: Mistborn: The Final Empire
# Author: Brandon Sanderson

import inspect

from mirascope.core import BaseMessageParam, prompt_template


@prompt_template()
def recommend_book_prompt(
    genres: list[str], examples: list[list[str]]
) -> list[BaseMessageParam]:
    formatted_genres = "\n".join(genres)
    formatted_examples = "\n\n".join(["\n".join(e) for e in examples])
    return [
        BaseMessageParam(
            role="user",
            content=inspect.cleandoc(
                """
                Recommend a book from one of the following genres:
                {genres}

                Examples:
                {examples}
                """
            ).format(genres=formatted_genres, examples=formatted_examples),
        )
    ]


prompt = recommend_book_prompt(
    genres=["fantasy", "scifi", "mystery"],
    examples=[
        ["Title: The Name of the Wind", "Author: Patrick Rothfuss"],
        ["Title: Mistborn: The Final Empire", "Author: Brandon Sanderson"],
    ],
)
print(prompt)
# Output: [
#     BaseMessageParam(
#         role="user",
#         content="Recommend a book from one of the following genres:\nfantasy\nscifi\nmystery\n\nExamples:\nTitle: The Name of the Wind\nAuthor: Patrick Rothfuss\n\nTitle: Mistborn: The Final Empire\nAuthor: Brandon Sanderson",
#     )
# ]

print(prompt[0].content)
# Output:
# Recommend a book from one of the following genres:
# fantasy
# scifi
# mystery

# Examples:
# Title: The Name of the Wind
# Author: Patrick Rothfuss

# Title: Mistborn: The Final Empire
# Author: Brandon Sanderson

Computed Fields (Dynamic Configuration)¶

In Mirascope, we write prompt templates as functions, which enables dynamically configuring our prompts at runtime depending on the values of the template variables. We use the term "computed fields" to talk about variables that are computed and formatted at runtime.

In the following examples, we demonstrate using computed fields and dynamic configuration across all prompt templating methods. Of course, this is only actually necessary for string templates. For other methods you can simply format the computed fields directly and return Messages.Type as before.

However, there is value in always dynamically configuring computed fields for any and all prompt templating methods. While we cover this in more detail in the Calls and Chaining sections, the short of it is that it enables proper tracing even across nested calls and chains.

ShorthandMessagesString TemplateBaseMessageParam

from mirascope.core import BaseDynamicConfig, Messages, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> BaseDynamicConfig:
    uppercase_genre = genre.upper()
    messages = [Messages.User(f"Recommend a {uppercase_genre} book")]
    return {
        "messages": messages,
        "computed_fields": {"uppercase_genre": uppercase_genre},
    }


print(recommend_book_prompt("fantasy"))
# Output: {
#     "messages": [BaseMessageParam(role="user", content="Recommend a FANTASY book")],
#     "computed_fields": {"uppercase_genre": "FANTASY"},
# }

from mirascope.core import BaseDynamicConfig, Messages, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> BaseDynamicConfig:
    uppercase_genre = genre.upper()
    messages = [Messages.User(f"Recommend a {uppercase_genre} book")]
    return {
        "messages": messages,
        "computed_fields": {"uppercase_genre": uppercase_genre},
    }


print(recommend_book_prompt("fantasy"))
# Output: {
#     "messages": [BaseMessageParam(role="user", content="Recommend a FANTASY book")],
#     "computed_fields": {"uppercase_genre": "FANTASY"},
# }

from mirascope.core import BaseDynamicConfig, prompt_template


@prompt_template("Recommend a {uppercase_genre} book")
def recommend_book_prompt(genre: str) -> BaseDynamicConfig:
    uppercase_genre = genre.upper()
    return {
        "computed_fields": {"uppercase_genre": uppercase_genre},
    }


print(recommend_book_prompt("fantasy"))
# Output: [BaseMessageParam(role='user', content='Recommend a FANTASY book')]

from mirascope.core import BaseDynamicConfig, BaseMessageParam, prompt_template


@prompt_template()
def recommend_book_prompt(genre: str) -> BaseDynamicConfig:
    uppercase_genre = genre.upper()
    messages = [
        BaseMessageParam(role="user", content=f"Recommend a {uppercase_genre} book")
    ]
    return {
        "messages": messages,
        "computed_fields": {"uppercase_genre": uppercase_genre},
    }


print(recommend_book_prompt("fantasy"))
print(recommend_book_prompt("fantasy"))
# Output: {
#     "messages": [BaseMessageParam(role="user", content="Recommend a FANTASY book")],
#     "computed_fields": {"uppercase_genre": "FANTASY"},
# }

There are various other parts of an LLM API call that we may want to configure dynamically as well, such as call parameters, tools, and more. We cover such cases in each of their respective sections.

Next Steps¶

By mastering prompts in Mirascope, you'll be well-equipped to build robust, flexible, and reusable LLM applications.

Next, we recommend taking a look at the Calls documentation, which shows you how to use your prompt templates to actually call LLM APIs and generate a response.

Prompts¶

Prompt Templates (Messages)¶

Message Roles¶

Multi-Line Prompts¶

Multi-Modal Inputs¶

Image Inputs¶

Audio Inputs¶

Chat History¶

Object Attribute Access¶

Format Specifiers¶

Computed Fields (Dynamic Configuration)¶

Next Steps¶