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Simon Willison

Here are my custom instructions which I'm using as part of a Claude Project, but I expect they'll work the same way with other LLMs too

You write Python tools as single files. They always start with this comment: # /// script # requires-python = ">=3.12" # /// These files can include dependencies on libraries such as Click. If they do, those dependencies are included in a list like this one in that same comment (here showing two dependencies): # /// script # requires-python = ">=3.12" # dependencies = [ # "click", # "sqlite-utils", # ] # ///
19 December at 13:17 | Open on fedi.simonwillison.net
14 comments
Jeff Triplett

@simon I am happy to see you are using this. I wasn't doing as much one-shot attempts with Projects when we talked at DCUS but sometimes that's what the results are.

I have been playing with MCP and it has a ton of potential but both the UI and the quality was a huge drop after two days of near perfection. Not sure if you tried that out yet, but I haven't tried it in the last two weeks. (I suspect it was an obvious bug)

Happy to compare notes some times.

19 December at 13:23 | Open on mastodon.social
Simon Willison

I have a similar set of custom instructions I use with Claude Artifacts to get it to produce mobile-friendly single page HTML apps that run without a build step

Never use React in artifactsβ€”always plain HTML and vanilla JavaScript and CSS with minimal dependencies. CSS should be indented with two spaces and should start like this: <style> * { box-sizing: border-box; } Inputs and textareas should be font size 16px. Font should always prefer Helvetica. JavaScript should be two space indents and start like this: <script type="module"> // code in here should not be indented at the first level
19 December at 13:47 | Open on fedi.simonwillison.net
Evan Prodromou

@simon you don't allow Web Components?

19 December at 14:08 | Open on cosocial.ca
Simon Willison

@evan love Web Components - I often prompt it to create those directly, but I still want them all in a single file so I can easily copy and paste the whole lot out of the LLM at once

19 December at 14:45 | Open on fedi.simonwillison.net
Evan Prodromou

@simon So, you don’t use an IDE with integrated AI, like VSCode with CoPilot or Cursor or Zed or whatever?

19 December at 15:53 | Open on cosocial.ca
Simon Willison

@evan I use GitHub copilot but I get a ton of work done directly in Claude (with Artifacts) and ChatGPT (with Code Interpeter) pasting code back and forth

19 December at 16:07 | Open on fedi.simonwillison.net
Evan Prodromou

@simon last question! Do you ever use a local Open Suorce model for code generation, and if so, which one?

19 December at 16:30 | Open on cosocial.ca
Simon Willison
Simon Willison

@evan both of them use so much memory that I have to shut down a bunch of Firefox tabs and VS code windows first - plus they're noticeably slower than the best hosted models

19 December at 16:36 | Open on fedi.simonwillison.net
Kyle Howells

@simon @evan I also only use local models on flights really. However, I will say I've found the smaller Qwen2.5-coder models on Ollama to be good enough, and importantly fast enough for most simple boiler plate work without taking up all my ram to run them.

20 December at 6:26 | Open on mastodon.social
Prem Kumar Aparanji πŸ‘ΆπŸ€–πŸ˜

@simon loving that you explicitly deny react πŸ˜…

19 December at 14:18 | Open on mastodon.social
Simon Willison

@prem_k with Claude Artifacts you have to or it defaults to writing you a React component every time!

19 December at 14:46 | Open on fedi.simonwillison.net
Prem Kumar Aparanji πŸ‘ΆπŸ€–πŸ˜

@simon true that ... I say some version of "native JavaScript without libraries as much as possible"

19 December at 14:48 | Open on mastodon.social
mikeful

@simon Put Zen of Python in the prompt and see if it generates better Python code.

19 December at 14:04 | Open on mastodontti.fi
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