Claude Code for Data People: Your First Session
Claude Code handles the basic analysis well. You know what to ask it, how to check what it did, and which number you put your name on.
You go at your own pace, with your Maestro beside you, 1:1, through the whole course: ask it anything, and it asks you questions too.
18 skills · 5 modules
What will you be able to do?
Each box is a skill. The base is at the bottom, recognizing and explaining, and you work your way up to building something of your own and judging what works and why. Hover over a box to see what it builds on. Click it to see where I teach it and how your Maestro checks it.
- Apply
- Understand
- Remember
Apply
Run a first agent session on a real data task and inspect what the agent did
Where I teach it: Your First Session with Data · Your first session: ask a real table a question
Builds on:
- Distinguish the model, the harness, and the context in an AI agent
- Know how agents reach tools and data: commands, connectors, files, and credentials
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Check a result against expectations: order of magnitude, totals, ranges, and known benchmarks
Where I teach it: Your First Session with Data · What is a row? The question that changes the number
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Give an agent the least access it needs, and separate read access from write access
Where I teach it: Claude Code and Your Excel Files · Can Claude Code work with my Excel files?
Builds on:
- Know how agents reach tools and data: commands, connectors, files, and credentials
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Trace a number back through its transformations to its source data
Where I teach it: Claude Code and Your Excel Files · Check the sheet before you send it
Builds on:
- Know what data provenance is: where a dataset came from, how it was collected, and what was done to it
- Identify the grain of a table: what one row represents
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Spot-check a result by recomputing a few rows by hand, spread across the start, middle, and end
Where I teach it: Claude Code and Your Excel Files · Check the sheet before you send it
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Write persistent context that an agent reads at the start of every session
Where I teach it: CLAUDE.md for a Data Project · What is CLAUDE.md, and what goes in it for a data project?
Builds on:
- Understand that an agent knows only what is in its context, and that context is limited and does not persist by default
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Understand
Explain how an agent works: it reads context, calls tools, observes results, and repeats
Where I teach it: What Claude Code Is and How to Start · What is Claude Code, and what can it do with data?
Builds on:
- Distinguish the model, the harness, and the context in an AI agent
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Distinguish the model, the harness, and the context in an AI agent
Where I teach it: What Claude Code Is and How to Start · What is Claude Code, and what can it do with data?
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Understand that supervising automated work requires the expertise the automation replaces
Where I teach it: What Claude Code Is and How to Start · Do I need to know how to code to use Claude Code?
Builds on:
- Understand AI in data work as an extension of a person's expertise, with the person accountable for the result
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Understand AI in data work as an extension of a person's expertise, with the person accountable for the result
Where I teach it: What Claude Code Is and How to Start · Do I need to know how to code to use Claude Code?
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Read the record of what an agent did: the commands it ran, the files it changed, and the results it saw
Where I teach it: Your First Session with Data · What did Claude Code do? Read what it ran
Builds on:
- Explain how an agent works: it reads context, calls tools, observes results, and repeats
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Identify the grain of a table: what one row represents
Where I teach it: Your First Session with Data · What is a row? The question that changes the number
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Remember
Know how agents reach tools and data: commands, connectors, files, and credentials
Where I teach it: What Claude Code Is and How to Start · What is Claude Code, and what can it do with data?
Your Maestro asks you to recognize and recall it and saves it as evidence when you do.
Know what data provenance is: where a dataset came from, how it was collected, and what was done to it
Where I teach it: Your First Session with Data · What is a row? The question that changes the number
Your Maestro asks you to recognize and recall it and saves it as evidence when you do.
Who is this course for?
For people who work with tables in Excel, CSV files or databases and want to start with Claude Code without knowing how to code: analysts, accountants, people in finance, research or government. You need a paid Claude plan to run Claude Code; the course is free.
Ask your Maestro
Your Maestro is an AI that knows this course. Ask it about the first page and it answers right here, free.
You: Where do I start?
Your Maestro: From what you already know. Tell me what you've done with data, and I'll start this page from there.
Asking about: Answers from the page "What is Claude Code, and what can it do with data?"
Only this browser keeps what you ask here. How it works
What we'll cover
What Claude Code Is and How to Start
Your First Session with Data
Claude Code and Your Excel Files
CLAUDE.md for a Data Project
Claude Code Skills for Data
How long does it take?
1 to 2 hours
A guide: you go at your own pace, and the course waits where you left off.
Common questions
- What is Claude Code, and what can it do with data?
- Claude Code is an AI agent from Anthropic that works in a folder on your computer: it reads your files, runs commands and code, looks at the result and keeps going. With data, it downloads a table, counts it, makes charts or builds you an Excel workbook with formulas. Unlike a chat, it works on your actual files, and it tells you what it ran so you can check it.
- Is there a free Claude Code course?
- Yes, this one. It's 13 free pages you can read without an account. Sign in with your email and your Maestro answers you on every page while you run your first session. The whole course uses public NASA data, so nothing from your job is exposed.
- Do I need to know how to code to use Claude Code?
- No. You can use Claude Code from the Claude desktop app, with no terminal, and ask for everything in plain language. Claude Code writes and runs the code; you read what it did. In the course you learn to read a short script well enough to know what it counted, which is what you really need before you sign off on a number.
- Is Claude Code free?
- No. Claude Code needs a paid Claude plan (Pro or higher) or Anthropic API credits. The free Claude plan doesn't include it. This course is free.
- Can Claude Code work with my Excel files?
- Yes. Claude Code reads and writes .xlsx files with Python. In the course you ask it for a workbook with a data sheet and a summary sheet where every number is an Excel formula, without touching the original file. Then you open the sheet and follow a formula back to the data.
- What is CLAUDE.md?
- It's a text file in your project folder that Claude Code reads at the start of every session. You write down what it always needs to know about your data, like what a row stands for or which file must never change. In the course you write your own and see how it changes the answer in a fresh session.
- What are Claude Code skills?
- A skill is a folder with a SKILL.md file: instructions for a task you repeat. Claude Code loads it when your request matches its description, or when you type /skill-name. In the course you build one that checks a table before anything gets counted.
- Is it for accountants, analysts or people who live in Excel?
- Yes. The course is for anyone who works with tables and answers for the number: accounting, finance, research, government, sales. It doesn't assume Python or statistics. It assumes you know your data, and it teaches you to put that expertise in front of Claude Code.
- What comes after this course?
- The paid course Claude Code for Data: Your Judgment, at Scale. There you work with your own data, specify tasks, verify results another way and turn a session into a procedure. What you show in this free course already counts there.
How do I check what AI does? I teach it in Your AI and Your Data: Don't Let It Make Up the Number and Check what AI gives you in three steps.
What you get
- 5 modules and 13 pages, open whenever you want them.
Open to everyone: read all of it, and your Maestro, an AI, answers your questions on every page.
With a free account: your Maestro for the whole course, always on the page you're on, and the exercises run with nothing to install.
Words you'll meet
In the lessons, tap one to see what it means, or ask your Maestro about it.
Who's teaching you
Sergio Sánchez
I teach this because Claude Code now does a lot of the data work that used to be yours: it downloads the table, cleans it, counts and builds the spreadsheet. What the table doesn't tell you is still on you: what a row stands for, what counts and what doesn't, when a number is ready for your report. This course is your first session with that split of the work.
I'm Sergio, chekos online. I'm a data architect, and I've spent more than ten years working with data in the Bay Area, mostly at mission-driven organizations: policy research first, then education, and now early childhood services. I grew up in Tijuana. In 2018 I started tacosdedatos to share what I was learning, and since then it's been a blog, a podcast, courses, guides, and a community. These days I spend a lot of my time building with AI agents and writing about how I organize my work around them. I share what I've learned; you take what's useful and make it yours.
See you in the course
Claude Code for Data People: Your First Session