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Build AI-powered scripts with the fm CLI and Python SDK
Explore all the new ways to leverage Apple Foundation Models on macOS. The Foundation Models SDK for Python lets you integrate with popular tooling and evaluation packages in the Python ecosystem. Find out how to use the brand new fm command introduced in macOS 27 to streamline scripting, automate model workflows, and accelerate your development process.
Chapters
- 0:00 - Introduction
- 1:22 - Introducing the fm CLI and Python SDK
- 3:23 - Command line tool
- 5:02 - fm respond and structured output
- 6:11 - Automating file management with fm
- 8:52 - Python SDK
- 9:42 - Prompting, tool calling and guided generation
- 10:44 - Building an evaluation pipeline in Python
- 15:20 - Next steps
Resources
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5:07 - Prompt the on-device model with fm respond
$ fm respond "Provide a basic regex in Swift to parse an email address" # Here is a basic regex to parse an email address in Swift: [...] $ fm respond "Provide a comprehensive regex in Swift to parse an email address" --model pcc # [...] Here's a robust Swift implementation using 'NSRegularExpression' to validate a typical email address: $ fm respond "What app is the user using in this screenshot?" --model pcc \ --image Screenshot.png # The user is using the Mail app. $ fm schema object --name AppsIdentified --string app_names --array > schema.json $ fm respond "What apps are the user actively using in this screenshot?" \ --image Screenshot.png --model pcc --schema schema.json # {"app_names": ["Messages", "Mail", "Calendar"]} $ fm respond --help -
7:55 - Sort files with fm respond and a schema
fm schema object --name "TriagedFileList" \ --string 'final_files' --array \ --string 'draft_files' --array > /tmp/schema.json output=$(fm respond \ --instructions "I just completed a project, and I need help triaging the latest version of the files from the previous versions. I will give you a list of files. Return a list of the latest files (i.e., all files that, you can infer from their name in the list, are the latest versions), and then return separately a list of all draft files (i.e., all files that weren't considered final)." \ "This is the list of all files:\n\n${files_list}" \ --schema /tmp/schema.json ) echo "${output}" | jq -r '.final_files[]' | while read -r file; do cp "${DIRECTORY_TO_TRIAGE}/${file}" "${FINAL_FILES_STORAGE_DIRECTORY}" done echo "${output}" | jq -r '.draft_files[]' | while read -r file; do mv "${DIRECTORY_TO_TRIAGE}/${file}" "${DRAFT_FILES_STORAGE_DIRECTORY}" done -
8:54 - Install the Foundation Models Python SDK
pip install apple_fm_sdk -
10:00 - Create a session and respond to a prompt
import apple_fm_sdk as fm INSTRUCTIONS = "You're an AI assistant for Cupertino Mart, a grocery store with in-app ordering." async def answer_question(prompt: str) -> str: session = fm.LanguageModelSession(instructions=INSTRUCTIONS) return await session.respond(prompt) -
10:21 - Define a Tool for the language model
class GetPastOrdersTool(fm.Tool): name = "get_past_orders" description = "Retrieves information about this user's past orders." @fm.generable("Past orders query parameter") class Arguments: number_orders: str = fm.guide("How many of the last orders to retrieve") @property def arguments_schema(self) -> fm.GenerationSchema: return self.Arguments.generation_schema() async def call(self, args: fm.GeneratedContent) -> str: number_orders = args.value(int, for_property="number_orders") return await Orders.load_last_orders(user_id=user_id, amount=number_orders) -
10:35 - Generate structured output with @fm.generable
@fm.generable("Suggested items") class ItemsSuggestion: item_names: list[str] = fm.guide("Names of the suggested items") INSTRUCTIONS = "You're an AI assistant tasked with returning potential grocery items that the user might be interested in." async def generate_suggested_cart_items(user_input: Optional[str]) -> ItemsSuggestion: session = fm.LanguageModelSession(instructions=INSTRUCTIONS, tools=load_tools()) prompt = """Using the tools to load the user's previous orders, \ return a list of items the user has already ordered \ and that they might be interested in again \ as they're getting ready to place a new grocery order.""" if user_input is not None: prompt += f"\nAccount for the following request from the user: {user_input}" return await session.respond(prompt, generating=ItemsSuggestion)
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- 0:00 - Introduction
Overview of the Foundation Models Framework — guided generation, tool calling, and new macOS 27 features like image inputs and server model access.
- 1:22 - Introducing the fm CLI and Python SDK
Two new ways to access Apple Foundation Models on macOS: the fm command line tool (pre-installed with macOS 27 for terminal-based prompting and automation) and the Foundation Models SDK for Python (for ML engineers who work more in Python than Swift).
- 3:23 - Command line tool
How to use the fm command line tool — browsing available commands, starting an interactive conversation with fm chat, switching between the on-device and Private Cloud Compute models, and saving sessions to resume later.
- 5:02 - fm respond and structured output
How to use fm respond for inline scripting — passing prompts and getting responses as terminal output, using the model and image options, and combining fm schema object with the schema option to produce structured JSON outputs.
- 6:11 - Automating file management with fm
A practical automation demo: using fm in a shell script to intelligently sort a messy presentation folder — prompting the model with a file list to classify drafts versus finals, generating structured JSON output, and routing files to backup and archive accordingly.
- 8:52 - Python SDK
Introduction to the Foundation Models SDK for Python — installation requirements (Python 3.10+, Xcode, Apple Silicon), core features mirroring the Swift framework (text and image inputs, streaming, tool calling, guided generation), and its value for ML engineers and rapid prototyping.
- 9:42 - Prompting, tool calling and guided generation
How to use the Python SDK in a grocery app prototype — creating a LanguageModelSession, calling session.respond with a prompt, exposing tools for the model to fetch order history, and using the fm.generable decorator for structured output into a typed ItemsSuggestion object.
- 10:44 - Building an evaluation pipeline in Python
A case study using the Python SDK with Jupyter, Pandas, and matplotlib to evaluate three prompt implementations for a cart completion feature — generating outputs with the on-device model, scoring them with a server judge model on criteria like excess items, missing items, and hallucinations, and visualizing results to guide prompt iteration.
- 15:20 - Next steps
Summary of the new macOS tools and next steps: explore fm in Terminal, visit the Python SDK GitHub for example snippets, and build an evaluation pipeline to measure and improve prompt quality.