Functions

Define a function using def:

def add(a: number, b: number): number {
  return a + b
}
print(add(4, 5))

Tool calls

Any function defined in Agency can automatically be used as a tool for the LLM. Pass the function in the tools option:

def add(a: number, b: number): number {
  return a + b
}

const result = llm("What is 4 + 5?", tools: [add])
print(result)

LLM calls are covered in more detail in the chapter on LLMs.

Docstrings

The docstring of a function will be sent to the LLM as a description of the tool. This can help the LLM understand what the function does and how to use it.

def add(a: number, b: number): number {
  """
  Adds two numbers together.
  """
  return a + b
}

Default arguments, optional arguments, and variadic arguments

Default arguments:

def round(num: number, decimals: number = 2): number

Optional arguments:

def greet(name: string, greeting?: string): string

Variadic arguments:

def print(...messages: string[]): void

Named arguments

def greet(name: string = "Adit", greeting: string = "Hello"): string {
  return `${greeting}, ${name}!`
}

// used a named arg
greet(name: "Alice")

// we can jump to the second arg, since the first arg has a default value
greet(greeting: "Hi")

// we can switch the order
greet(greeting: "Hi", name: "Bob")

Blocks

Functions can also take blocks. This is a way to pass a chunk of code to a function. If you're used lambda functions in other languages, this is similar.

def repeat(n: number, block: () -> any) {
  for (i in range(n)) {
    block()
  }
}

Blocks are covered in more detail in the section on blocks.