23 items tagged “tools”
2024
GitHub OAuth for a static site using Cloudflare Workers. Here's a TIL covering a Thanksgiving AI-assisted programming project. I wanted to add OAuth against GitHub to some of the projects on my tools.simonwillison.net site in order to implement "Save to Gist".
That site is entirely statically hosted by GitHub Pages, but OAuth has a required server-side component: there's a client_secret
involved that should never be included in client-side code.
Since I serve the site from behind Cloudflare I realized that a minimal Cloudflare Workers script may be enough to plug the gap. I got Claude on my phone to build me a prototype and then pasted that (still on my phone) into a new Cloudflare Worker and it worked!
... almost. On later closer inspection of the code it was missing error handling... and then someone pointed out it was vulnerable to a login CSRF attack thanks to failure to check the state=
parameter. I worked with Claude to fix those too.
Useful reminder here that pasting code AI-generated code around on a mobile phone isn't necessarily the best environment to encourage a thorough code review!
QuickTime video script to capture frames and bounding boxes. An update to an older TIL. I'm working on the write-up for my DjangoCon US talk on plugins and I found myself wanting to capture individual frames from the video in two formats: a full frame capture, and another that captured just the portion of the screen shared from my laptop.
I have a script for the former, so I got Claude to update my script to add support for one or more --box
options, like this:
capture-bbox.sh ../output.mp4 --box '31,17,100,87' --box '0,0,50,50'
Open output.mp4
in QuickTime Player, run that script and then every time you hit a key in the terminal app it will capture three JPEGs from the current position in QuickTime Player - one for the whole screen and one each for the specified bounding box regions.
Those bounding box regions are percentages of the width and height of the image. I also got Claude to build me this interactive tool on top of cropperjs to help figure out those boxes:
Claude Token Counter. Anthropic released a token counting API for Claude a few days ago.
I built this tool for running prompts, images and PDFs against that API to count the tokens in them.
The API is free (albeit rate limited), but you'll still need to provide your own API key in order to use it.
Here's the source code. I built this using two sessions with Claude - one to build the initial tool and a second to add PDF and image support. That second one is a bit of a mess - it turns out if you drop an HTML file onto a Claude conversation it converts it to Markdown for you, but I wanted it to modify the original HTML source.
The API endpoint also allows you to specify a model, but as far as I can tell from running some experiments the token count was the same for Haiku, Opus and Sonnet 3.5.
Everything I built with Claude Artifacts this week
I’m a huge fan of Claude’s Artifacts feature, which lets you prompt Claude to create an interactive Single Page App (using HTML, CSS and JavaScript) and then view the result directly in the Claude interface, iterating on it further with the bot and then, if you like, copying out the resulting code.
[... 2,273 words]Dashboard: Tools. I used Django SQL Dashboard to spin up a dashboard that shows all of the URLs to my tools.simonwillison.net site that I've shared on my blog so far. It uses this (Claude assisted) regular expression in a PostgreSQL SQL query:
select distinct on (tool_url)
unnest(regexp_matches(
body,
'(https://tools\.simonwillison\.net/[^<"\s)]+)',
'g'
)) as tool_url,
'https://simonwillison.net/' || left(type, 1) || '/' || id as blog_url,
title,
date(created) as created
from content
I've been really enjoying having a static hosting platform (it's GitHub Pages serving my simonw/tools repo) that I can use to quickly deploy little HTML+JavaScript interactive tools and demos.
Markdown and Math Live Renderer.
Another of my tiny Claude-assisted JavaScript tools. This one lets you enter Markdown with embedded mathematical expressions (like $ax^2 + bx + c = 0$
) and live renders those on the page, with an HTML version using MathML that you can export through copy and paste.
Here's the Claude transcript. I started by asking:
Are there any client side JavaScript markdown libraries that can also handle inline math and render it?
Claude gave me several options including the combination of Marked and KaTeX, so I followed up by asking:
Build an artifact that demonstrates Marked plus KaTeX - it should include a text area I can enter markdown in (repopulated with a good example) and live update the rendered version below. No react.
Which gave me this artifact, instantly demonstrating that what I wanted to do was possible.
I iterated on it a tiny bit to get to the final version, mainly to add that HTML export and a Copy button. The final source code is here.
YouTube Thumbnail Viewer.
I wanted to find the best quality thumbnail image for a YouTube video, so I could use it as a social media card. I know from past experience that GPT-4 has memorized the various URL patterns for img.youtube.com
, so I asked it to guess the URL for my specific video.
This piqued my interest as to what the other patterns were, so I got it to spit those out too. Then, to save myself from needing to look those up again in the future, I asked it to build me a little HTML and JavaScript tool for turning a YouTube video URL into a set of visible thumbnails.
I iterated on the code a bit more after pasting it into Claude and ended up with this, now hosted in my tools collection.
files-to-prompt 0.3.
New version of my files-to-prompt
CLI tool for turning a bunch of files into a prompt suitable for piping to an LLM, described here previously.
It now has a -c/--cxml
flag for outputting the files in Claude XML-ish notation (XML-ish because it's not actually valid XML) using the format Anthropic describe as recommended for long context:
files-to-prompt llm-*/README.md --cxml | llm -m claude-3.5-sonnet \
--system 'return an HTML page about these plugins with usage examples' \
> /tmp/fancy.html
The format itself looks something like this:
<documents>
<document index="1">
<source>llm-anyscale-endpoints/README.md</source>
<document_content>
# llm-anyscale-endpoints
...
</document_content>
</document>
</documents>
Share Claude conversations by converting their JSON to Markdown. Anthropic's Claude is missing one key feature that I really appreciate in ChatGPT: the ability to create a public link to a full conversation transcript. You can publish individual artifacts from Claude, but I often find myself wanting to publish the whole conversation.
Before ChatGPT added that feature I solved it myself with this ChatGPT JSON transcript to Markdown Observable notebook. Today I built the same thing for Claude.
Here's how to use it:
The key is to load a Claude conversation on their website with your browser DevTools network panel open and then filter URLs for chat_
. You can use the Copy -> Response right click menu option to get the JSON for that conversation, then paste it into that new Observable notebook to get a Markdown transcript.
I like sharing these by pasting them into a "secret" Gist - that way they won't be indexed by search engines (adding more AI generated slop to the world) but can still be shared with people who have the link.
Here's an example transcript from this morning. I started by asking Claude:
I want to breed spiders in my house to get rid of all of the flies. What spider would you recommend?
When it suggested that this was a bad idea because it might attract pests, I asked:
What are the pests might they attract? I really like possums
It told me that possums are attracted by food waste, but "deliberately attracting them to your home isn't recommended" - so I said:
Thank you for the tips on attracting possums to my house. I will get right on that! [...] Once I have attracted all of those possums, what other animals might be attracted as a result? Do you think I might get a mountain lion?
It emphasized how bad an idea that would be and said "This would be extremely dangerous and is a serious public safety risk.", so I said:
OK. I took your advice and everything has gone wrong: I am now hiding inside my house from the several mountain lions stalking my backyard, which is full of possums
Claude has quite a preachy tone when you ask it for advice on things that are clearly a bad idea, which makes winding it up with increasingly ludicrous questions a lot of fun.
Image resize and quality comparison. Another tiny tool I built with Claude 3.5 Sonnet and Artifacts. This one lets you select an image (or drag-drop one onto an area) and then displays that same image as a JPEG at 1, 0.9, 0.7, 0.5, 0.3 quality settings, then again but with at half the width. Each image shows its size in KB and can be downloaded directly from the page.
I'm trying to use more images on my blog (example 1, example 2) and I like to reduce their file size and quality while keeping them legible.
The prompt sequence I used for this was:
Build an artifact (no React) that I can drop an image onto and it presents that image resized to different JPEG quality levels, each with a download link
Claude produced this initial artifact. I followed up with:
change it so that for any image it provides it in the following:
- original width, full quality
- original width, 0.9 quality
- original width, 0.7 quality
- original width, 0.5 quality
- original width, 0.3 quality
- half width - same array of qualities
For each image clicking it should toggle its display to full width and then back to max-width of 80%
Images should show their size in KB
Claude produced this v2.
I tweaked it a tiny bit (modifying how full-width images are displayed) - the final source code is available here. I'm hosting it on my own site which means the Download links work correctly - when hosted on claude.site
Claude's CSP headers prevent those from functioning.
Compare PDFs. Inspired by this thread on Hacker News about the C++ diff-pdf tool I decided to see what it would take to produce a web-based PDF diff visualization tool using Claude 3.5 Sonnet.
It took two prompts:
Build a tool where I can drag and drop on two PDF files and it uses PDF.js to turn each of their pages into canvas elements and then displays those pages side by side with a third image that highlights any differences between them, if any differences exist
That give me a React app that didn't quite work, so I followed-up with this:
rewrite that code to not use React at all
Which gave me a working tool! You can see the full Claude transcript in this Gist. Here's a screenshot of the tool in action:
Being able to knock out little custom interactive web tools like this in a couple of minutes is so much fun.
Wrap text at specified width. New Observable notebook. I built this with the help of Claude 3 Opus—it’s a text wrapping tool which lets you set the width and also lets you optionally add a four space indent.
The four space indent is handy for posting on forums such as Hacker News that treat a four space indent as a code block.
Tools are the things we build that we don't ship - but that very much affect the artifact that we develop.
It can be tempting to either shy away from developing tooling entirely or (in larger organizations) to dedicate an entire organization to it.
In my experience, tooling should be built by those using it.
This is especially true for tools that improve the artifact by improving understanding: the best time to develop a debugger is when debugging!
2023
ast-grep (via) There are a lot of interesting things about this year-old project.
sg (an alias for ast-grep) is a CLI tool for running AST-based searches against code, built in Rust on top of the Tree-sitter parsing library. You can run commands like this:
sg -p ’await await_me_maybe($ARG)’ datasette --lang python
To search the datasette directory for code that matches the search pattern, in a syntax-aware way.
It works across 19 different languages, and can handle search-and-replace too, so it can work as a powerful syntax-aware refactoring tool.
My favourite detail is how it’s packaged. You can install the CLI utility using Homebrew, Cargo, npm or pip/pipx—each of which will give you a CLI tool you can start running. On top of that it provides API bindings for Rust, JavaScript and Python!
How I make annotated presentations
Giving a talk is a lot of work. I go by a rule of thumb I learned from Damian Conway: a minimum of ten hours of preparation for every one hour spent on stage.
[... 2,128 words]2019
free-for.dev (via) It’s pretty amazing how much you can build on free tiers these days—perfect for experimenting with side-projects. free-for.dev collects free SaaS tools for developers via pull request, and has had contributions from over 500 people.
2009
Unicode code converter (via) Fantastically useful tool to convert strings of characters in to every unicode and/or escaping syntax you can possibly imagine.
Toy Chest: Online or Downloadable Tools for Building Projects (via) “Toy Chest collects online or downloadable software tools/thinking toys that humanities students and others without programming skills (but with basic computer and Internet literacy) can use to create interesting projects”—a fantastic list compiled by the English Department at UCSB.
Hack Day tools for non-developers
We’re about to run our second internal hack day at the Guardian. The first was an enormous amount of fun and the second one looks set to be even more productive.
[... 920 words]Nmap 5.00 Release Notes. Released today, “the most important Nmap release since 1997”. New features include Ncat, a powerful netcat alternative, Ndiff, a utility for comparing scan results so you can spot changes to your network, and a new Nmap Scripting Engine using Lua.
Tools of the Modern Python Hacker: Virtualenv, Fabric and Pip. Ashamed to say I’m not using any of these yet—for Django projects, my manage.py inserts an “ext” directory at the beginning of the Python path which contains my dependencies for that project.
aws—simple access to Amazon EC2 and S3. The best command line client I’ve found for EC2 and S3. “aws put --progress my-bucket-name/large-file.tar.gz large-file.tar.gz” is particularly useful for uploading large files to S3. Written in Perl (with no dependencies), shelling out to curl to do the heavy lifting.
2007
The CSS Redundancy Checker. A tool for checking your markup for outdated CSS rules that don’t match any of your HTML. We were discussing the need for something similar to this at Torchbox a few weeks ago.