I help sustainability professionals build AI tools that save a week out of every month.
Hey {{first_name|there}},
First week without the AI Lab participants, and I already miss it. A room of 12 sustainability professionals, each solving a real problem for their business or client, each focused on building a tool and learning new skills, is just different. And the question they asked most in six weeks wasn't about prompts. It was: which of my tasks belongs in chat, which in Cowork, and which deserves to become real software? That's today's email.
Here's what usually happens.
Someone gets excited about Cowork
They give it a prompt
They get the same output as chat, if not worse
Two things are going on. Either they're treating it like chat, or they're giving it the wrong task.
Since 16 September, Chat and Cowork live in the same Claude window, and Claude decides whether your request is a quick answer or a job to run. But you still decide how you work with it. That's what this framework is about.
Chat — where you talk. You ask, it answers, you steer.
Cowork — where you delegate. You set the goal, it does the work and checks in.
Code — where you build. You describe a tool, it builds the software that runs it.
Each step up gives you more, and asks more of you: more to learn, more setup to invest in.
Chat: when the job lives in one conversation
One or two exchanges, maybe an attachment, and you're done. You won't come back to it.
Interpreting a single ESRS datapoint you're unsure about
Checking one green claim against the EU Empowering Consumers Directive before it goes public
Drafting a supplier email, or tightening a paragraph for a report
Thinking out loud: "does this belong in Scope 3 Cat. 1 or Cat. 7?"
You: steer every message. You get: an answer, a draft, a second opinion. Skill you need: good prompting.
Cowork: when you need the job done
Here the logic changes. It's not a Q&A. It's an agent you give a goal to, and it works toward it.
That's a superpower and a curse. Give it a vague goal with no system behind it, and you'll spend more time figuring out what went wrong than celebrating what worked.
Tasks I run this way:
My weekly sustainability updates. I stopped jumping across dozens of websites. One skill does it: the Monday Brief, now used by over 1,000 sustainability professionals.
A full materiality assessment, run as a skill.
EUDR screening across product SKUs, purchasing data and the regulation annex. Multi-step, multi-source.
Half-year environmental reporting, the one you saw live in the workshop: intake, validation, follow-up, consolidation, dashboard.
One goal, a clear SOP for Claude, task done. Not easy: you need to know how the goal is achieved, give the agent a roadmap, the right data, and the right checks. Then you have a system that delivers.
You: set the goal, it executes and checks in. You get: a finished deliverable. Skill you need: directing an agent and building a system around it. No code. Just control.
Code: when you need a tool that doesn't exist
The line between Cowork and Code is where people over- or under-invest.
If the process is still moving, still being figured out, stay in Cowork. Jump to Code when a proven method exists but no tool fits your process, and you want to build it your way.
EUDR — a Cowork problem. Still evolving, lots of steps that need judgment.
Carbon accounting — a Code problem. Proven methodology, but most tools are generic. Build the one that fits.
The 10-second test
Will I only do this once? — Chat.
Will I do this again, with the same context? — Cowork. Build the setup once.
Is the method proven, but no tool fits how I work? — Code.
Run your next three tasks through it. You'll be surprised how many "chat" tasks are really Cowork jobs you keep redoing by hand.
On Monday: how to set up Cowork properly, step by step.
FREE VALUE
Build your first skill
Skills are what turn a Cowork job from "explain it again every time" into "run it". This walkthrough shows how to build one as a sustainability manager. It saves you an hour or two on the first task you use it for.
Hit reply and tell me which task failed the test for you. I read every one.
— Zyad
Know your Cowork jobs, but not how to set them up?
In SustainOS Cowork we map your recurring tasks and build the setup together, for you or your whole team.
