Below is a condensed overview capturing the key lessons, best quotes, and how each piece connects to building a computer-using agent.

Segment Key Topics Summary Notable Quotes Computer-Use Relevance
1. Course Introduction & Anthropic Context - Anthropic’s focus on safety & alignment- Frontier AI research- Roadmap of the course Explains what a “computer-using agent” is, highlights Anthropic’s frontier research in alignment, interpretability, and model capabilities. Introduces the course structure, culminating in a demo of an agent interacting with a computer via screenshots and tools. “Anthropic is a unique AI lab that has a very heavy focus on research that puts safety at the very frontier.”“One of the things I encourage you to do if you’re interested is to read some of our blog posts… interpretability research.” Provides the conceptual foundation of how AI models can be made to responsibly control external systems, such as a virtual computer environment.
2. Models & Parameters - Claude 3.5 Sonnet vs. Haiku- Context window & token limits- Basic text calls Introduces the different Claude 3.5 models (Sonnet, Haiku), including speed, token limits (200k context), and best practices for choosing a model. “Cloud 3.5 Sonnet is the most intelligent model we offer… multilingual, multimodal… works best on computer use tasks.”“We’re working with 200,000 tokens for the Context Window.” Understanding model limits (like context sizes) is crucial when building an agent that handles large prompts (e.g., many screenshots, chat history).
3. Basic Usage & Messages Format - messages array- Roles: “user” vs. “assistant”- Multi-turn chat structure Demonstrates how to format prompts in a conversation-like structure. Showcases single-turn usage and multi-turn chat by alternating user/assistant roles. “We can ‘put words in the model’s mouth’ by including an assistant message to prefill the model’s response.”“It’s the same basic concept… we send a request off to the model, get a response, and append it to our messages.” The entire computer-use flow is an iterative message exchange: the agent sees a screenshot, decides on a tool call, we feed that back, and so forth. This loop is built on the basic messages format.
4. Model Parameters & Stop Sequences - max_tokens- Temperature- Stop sequences Explains controlling generation length (max_tokens) and style (temperature), as well as forcing generation to stop on certain strings (stop sequences). “One reason is to try and save on API costs and set some sort of upper bound… also to improve speed.”“Stop sequences... one way to control when the model stops.” Fine-tuning generation is critical for stable, predictable tool usage. For example, you might limit length or stop on a custom delimiter to parse tool calls safely.
5. Multimodal Inputs - Images in prompts- Base64 encoding- Content blocks for text vs. image- Streaming responses Demonstrates combining images + text in a single request. Shows how to embed screenshots or scanned documents. Also covers response streaming (receiving tokens as they’re generated). “We do in fact see three boxes with plastic lids and three of the paper oyster pails.”“We can feed it [the invoice image] into Claude… ask it to give us structured data as a response.” In the computer-use agent, screenshots get passed to the model as images. The model inspects them (e.g., sees a browser window) and decides where to click, type, or scroll.
6. Real-World Prompting & Prompt Caching - Prompt design at scale- Caching repeated portions- TTL (5-minute ephemeral caching) Outlines how real apps often rely on consistent prompt prefixes. Caching a large prefix can cut costs and latency drastically. Explains ephemeral caching: each read resets a 5-minute TTL. “It also is a great cost-saving and latency-saving measure.”“Anytime you want to set a caching point… the API will cache all the input tokens up to this point.” Long multi-turn sessions with an agent can be expensive if the same screenshot or prefix is repeated. Prompt caching optimizes repeated context.
7. Tool Usage - Tools & tool result blocks- Parsing model requests to run code- Example: Database or web calls Shows how the model can request an action (e.g., “mouse_click”), and then the developer’s code executes it. The model never does it by itself; it emits a structured “tool use” message. “If the model wants to click or type, it outputs a tool block. We as developers must implement that function.”“You can build a tool for basically anything—shell commands, web requests, etc.” Fundamental for the computer-use agent. Tools unify the model’s instructions with real actions (mouse movement, keystrokes, or API calls).
8. Computer-Using Agent Demo - Agentic loop- Combining everything- CLI quickstart for local environment A final demonstration merges messaging, images, caching, tools, and vision. The agent sees screenshots, decides what to click, uses the “computer” tool to manipulate a virtual desktop, and can do tasks like opening a browser or downloading PDFs. “That computer-using agent… builds upon all the fundamentals of the API.”“It’s a very simple agentic loop… until the model decides ‘I’m done.’”“Finally, at the very end, you’ll see how to run the computer-using agent that you just saw.” Shows the end-to-end scenario: the agent inspects screenshots, calls “move_mouse” or “click,” and the environment returns new screenshots. This closes the loop for real interactive usage—browsing, automation, or data collection.

Use this table as a self-contained cheat-sheet for the entire course content. It highlights how each concept—messages, parameters, images, caching, and tool calls—ultimately converges to power a fully automated “computer-using” agent via Anthropic’s API.