Prompt Templates

Reusable, composable prompt builders.

`PromptTemplate`

Single-message prompt template with {variable} interpolation.

Variables in the template string are identified by curly-brace syntax {variable_name}. When input_variables is provided, only those names are required at render time; otherwise every {name} found in the template string is treated as required.

Usage:

python

tpl = PromptTemplate(
    template="Summarise in {words} words: {text}",
    input_variables=["text", "words"],
)
msg = tpl.render(text="Hello world", words=10)

Parameters:

Name	Type	Description
`template`	`str`	The template string with `{variable}` placeholders.
`input_variables`	`list[str]`	Explicit list of required variable names. When empty the variables are inferred from the template string.
`role`	`str`	The role of the produced `Message`. Defaults to `"user"`.

`ChatPromptTemplate`

Multi-turn prompt template producing a list of Message objects.

Supports ("role", "template {var}") tuples and bare Message instances in the messages list. Role aliases "human" → "user" and "ai" → "assistant" are resolved automatically.

Usage:

python

tpl = ChatPromptTemplate(
    messages=[
        ("system", "You speak {language}."),
        ("human", "{user_message}"),
    ],
    input_variables=["language", "user_message"],
)
msgs = tpl.render(language="French", user_message="Hello!")

Parameters:

Name	Type	Description
`messages`	`list[tuple[str, str] \| Message]`	Ordered list of `(role, template)` tuples or `Message` instances.
`input_variables`	`list[str]`	Explicit list of required variable names. When empty the variables are inferred by scanning all tuple templates.

`FewShotPromptTemplate`

Few-shot prompt template with injected examples.

The rendered content is assembled as: <prefix> <example_separator> <example_1> <example_separator> ... <suffix>

Usage:

python

tpl = FewShotPromptTemplate(
    prefix="Classify sentiment:\n",
    examples=[FewShotExample("Great!", "positive")],
    example_template="{input} -> {output}",
    suffix="Input: {review}\nSentiment:",
    input_variables=["review"],
)
msg = tpl.render(review="Terrible.")

Parameters:

Name	Type	Description
`prefix`	`str`	Text prepended before the examples.
`examples`	`list[FewShotExample]`	Static few-shot examples included in every render.
`example_template`	`str`	Template string for each example. Must contain `{input}` and `{output}` placeholders.
`suffix`	`str`	Template string appended after the examples. May contain `{variable}` placeholders resolved from kwargs.
`input_variables`	`list[str]`	Explicit list of required variable names for the suffix. When empty they are inferred from the suffix template.
`example_separator`	`str`	String used to join prefix, examples, and suffix. Defaults to `"\n\n"`.
`role`	`str`	Role of the produced `Message`. Defaults to `"user"`.

`FewShotExample`

A single input/output example for few-shot prompting.

Parameters:

Name	Type	Description
`input`	`str`	The example input text.
`output`	`str`	The expected output text.