He built a 141-feature finance app (without writing code)
So Chris Jarski, a Fractional CFO, and one of our AI Finance Club instructors, showed me something really cool.
He built a piece of software for a client, with 141 features, without being a developer.
He did it with Claude Code: he recorded what the client needed, turned it into a spec, and let Claude build the app. As their finance advisor, he already knew the business better than any software vendor did.
That is the top end of what Claude can now do for finance. And it's one of five different Claude tools finance pros still don’t know how to use, because they still think of is as a ‘chat bot’.
In March I wrote a previous newsletter on 3 things Claude does Better than ChatGPT (and whether you should switch), you can read it here.
But this question now is more than just "Claude or ChatGPT,"
Eight of the Fortune 10 are Claude customers. Apple and Amazon use it mainly for software development. And Bridgewater, Ray Dalio's fund, built its Investment Analyst Assistant on it.
Claude Code is great, but there’s a lot more that’s super relevant to finance pros that a lot of people are missing.
(that will still make your team think you hired an assistant)
So let me give you the full breakdown.
Claude isn't one tool. It's Five (and it’s confusing)
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1. Chat
What it is: The single chat box everyone knows. You type, it answers. Nothing is saved between chats (unless you turn on memory).
Examples use cases:
- Explain a tricky accounting standard or IFRS treatment in plain English
- Draft a reply to the auditor or a quick note to a stakeholder
- Upload a 40-page credit agreement and pull out the key covenants, triggers, and definitions
- Turn a complicated audit finding into plain English for a non-finance exec
- Simplify a board-paper paragraph that's too long or too jargon-heavy
2. Projects
What it is: A chat box with a memory and specific context. You add files and instructions once, and every chat inside inherits them.
Examples use cases:
- One Project per client or entity – term sheets, contracts and emails in one place
- One Project per board or committee, with the format and KPI definitions saved
- One Project per acquisition target – CIM, financials, diligence notes in one place
- One Project for the annual budget cycle – templates, prior-year actuals, assumptions doc
3. Cowork
What it is: An agent that works with the real files and folders on your computer, running multi-step tasks while checking in with you (automation without code).
This is the closest tool you'll find to an an assistant that can follow instructions, and work in the background whilst you complete other tasks.
Examples use cases:
- Bank rec: drop a folder of invoices plus the statement, get a 70–80% matched draft
- Expense categorization: map messy descriptions to the chart of accounts, flag the unclear ones
- Roll up a folder of entity trial balances into a group consolidation pack
- Three-way match POs, invoices, and goods-receipts across a folder and flag exceptions
- Compare actuals-vs-budget across cost-center files and flag variances over your threshold
Note – Claude Cowork also has plugins (combinations of Skills and settings that you can just load from their plugins marketplace) I spoke about their finance plug-in in detail in this newsletter.
4. Skills
What it is: A saved set of instructions for how you do a task, like onboarding a new employee once. Claude loads it on its own when it recognizes a trigger in the chat.
Examples use cases:
- Financial modelling skill: save your assumptions and tab layout per client type / business unit
- Board-pack skill: Takes your exact structure (exec summary, KPIs, cash waterfall, appendix) and creates slides whenever you mention ‘board prep’
- Variance analysis skill: Takes your data and generates the variance commentary in your exact reporting format
- Audit trail skill: Review your data or workflows every time you complete a task or analysis and automatically build a doc / Excel with audible steps
5. Code
What it is: The most advanced tool. You describe software, Claude builds it. I don’t really recommend this until you’re more advanced with AI, and have tried Claude Cowork first.
Examples use cases:
- Build an interactive scenario/sensitivity model the team uses from a link (instead of Excel)
- Automate the recurring ERP-export-to-formatted-report job you normally do manually
- A reconciliation app that runs your match logic over large transaction files as soon as they’re saved to a folder.
"But I can put a Project inside Cowork now?"
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So this is where things get confusing, because you can now create Projects inside Cowork too. The trick is to stop thinking of them as separate things.
A Project is the context: the files, the instructions, the memory of something like a client, entity, group of analysis files etc.
Chat and Cowork are where the work happens:
Projects tell Chat and Cowork how to behave with specific context and information.
- You can use Chat and Cowork without a Project (no context)
- You can’t use a Project without Chat or Cowork (context)
And Skills work across all of them.
Build your variance analysis Skill once, and it works everywhere you work.
ChatGPT vs Claude
So has ChatGPT closed the gap? On the concepts, yes. It now has its own Skills, and with GPT-5.5 and Workspace Agents it has agentic models that connect into your apps.
Cowork runs on your local files; ChatGPT’s Workspace Agents live in the cloud.
Claude reads about 1 million words of context at once against GPT-5.5's 400,000 (which matters when you’re handling lots of data)
On Microsoft 365 or Google?
Your decision is mostly already made.
So before you switch anything: if you're a Microsoft shop, Copilot now has its own Cowork and Agent, already inside your tools..
If you're on Google, you have Gemini. Use what you already pay for first. But there is no similar concept to Claude Cowork or ChatGPT Agents.
My View on Claude vs Other AIs
A lot of the hype you see around Claude Code is noise.
Just because developers at 8 of the Fortune 10 use it, doesn't mean it's the right tool for you.
But from today, you can see how to use Claude as a powerful assistant long before you ever get to Code.
So when people ask me in my masterclasses every week "which tool is best?" Here's what I say.
A lot of people switch to Claude but still don’t know how to use it and don’t get better results.
So, first, learn the current tool you have (you will do better than somebody who has Claude but doesn’t know how to use it).
But, if you have the choice and no sunk costs (or a company obligation for one tool) – As of today, my recommendation is to use Claude for most of your trivial finance tasks.
(btw – I still use ChatGPT as it has a lot of my history and is good for day to day conversations)
The 5-step Claude workflow that does your bank reconciliation in 30 minutes
So, now you have a playbook for understanding all of the tools within Claude.
The next step is to see me use them live in this 60-min Free Masterclass with Nominal.
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It’s one thing to know about the tool.
It’s another thing to see it in action.
So save your seat here before the spaces are gone.
See you there.
Best,
Your AI Finance Expert
– Nicolas
P.S. – Are you using Claude yet? Hit reply and let me know.
P.P.S – You just learned Claude's 5 tools. Now here's how to use Cowork for your finance workflows → Claude Cowork: Automate Finance Like a PRO