24 items tagged “claude-artifacts”
A feature of Claude where it can create shareable, executable HTML and JavaScript pages. See Everything I built with Claude Artifacts this week for several detailed examples.
2024
Building Python tools with a one-shot prompt using uv run and Claude Projects
I’ve written a lot about how I’ve been using Claude to build one-shot HTML+JavaScript applications via Claude Artifacts. I recently started using a similar pattern to create one-shot Python utilities, using a custom Claude Project combined with the dependency management capabilities of uv.
[... 873 words]3 shell scripts to improve your writing, or “My Ph.D. advisor rewrote himself in bash.” (via) Matt Might in 2010:
The hardest part of advising Ph.D. students is teaching them how to write.
Fortunately, I've seen patterns emerge over the past couple years.
So, I've decided to replace myself with a shell script.
In particular, I've created shell scripts for catching three problems:
- abuse of the passive voice,
- weasel words, and
- lexical illusions.
"Lexical illusions" here refers to the thing where you accidentally repeat a word word twice without realizing, which is particularly hard to spot if the repetition spans a line break.
Matt shares Bash scripts that he added to a LaTeX build system to identify these problems.
I pasted his entire article into Claude and asked it to build me an HTML+JavaScript artifact implementing the rules from those scripts. After a couple more iterations (I pasted in some feedback comments from Hacker News) I now have an actually quite useful little web tool:
tools.simonwillison.net/writing-style
Here's the source code and commit history.
ChatGPT Canvas can make API requests now, but it’s complicated
Today’s 12 Days of OpenAI release concerned ChatGPT Canvas, a new ChatGPT feature that enables ChatGPT to pop open a side panel with a shared editor in it where you can collaborate with ChatGPT on editing a document or writing code.
[... 1,116 words]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:
California Clock Change. The clocks go back in California tonight and I finally built my dream application for helping me remember if I get an hour extra of sleep or not, using a Claude Artifact. Here's the transcript.
This is one of my favorite examples yet of the kind of tiny low stakes utilities I'm building with Claude Artifacts because the friction involved in churning out a working application has dropped almost to zero.
(I added another feature: it now includes a note of what time my Dog thinks it is if the clocks have recently changed.)
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.
Bringing developer choice to Copilot with Anthropic’s Claude 3.5 Sonnet, Google’s Gemini 1.5 Pro, and OpenAI’s o1-preview. The big announcement from GitHub Universe: Copilot is growing support for alternative models.
GitHub Copilot predated the release of ChatGPT by more than year, and was the first widely used LLM-powered tool. This announcement includes a brief history lesson:
The first public version of Copilot was launched using Codex, an early version of OpenAI GPT-3, specifically fine-tuned for coding tasks. Copilot Chat was launched in 2023 with GPT-3.5 and later GPT-4. Since then, we have updated the base model versions multiple times, using a range from GPT 3.5-turbo to GPT 4o and 4o-mini models for different latency and quality requirements.
It's increasingly clear that any strategy that ties you to models from exclusively one provider is short-sighted. The best available model for a task can change every few months, and for something like AI code assistance model quality matters a lot. Getting stuck with a model that's no longer best in class could be a serious competitive disadvantage.
The other big announcement from the keynote was GitHub Spark, described like this:
Sparks are fully functional micro apps that can integrate AI features and external data sources without requiring any management of cloud resources.
I got to play with this at the event. It's effectively a cross between Claude Artifacts and GitHub Gists, with some very neat UI details. The features that really differentiate it from Artifacts is that Spark apps gain access to a server-side key/value store which they can use to persist JSON - and they can also access an API against which they can execute their own prompts.
The prompt integration is particularly neat because prompts used by the Spark apps are extracted into a separate UI so users can view and modify them without having to dig into the (editable) React JavaScript code.
Prompt GPT-4o audio. A week and a half ago I built a tool for experimenting with OpenAI's new audio input. I just put together the other side of that, for experimenting with audio output.
Once you've provided an API key (which is saved in localStorage) you can use this to prompt the gpt-4o-audio-preview model with a system and regular prompt and select a voice for the response.
I built it with assistance from Claude: initial app, adding system prompt support.
You can preview and download the resulting wav file, and you can also copy out the raw JSON. If you save that in a Gist you can then feed its Gist ID to https://tools.simonwillison.net/gpt-4o-audio-player?gist=GIST_ID_HERE (Claude transcript) to play it back again.
You can try using that to listen to my French accented pelican description.
There's something really interesting to me here about this form of application which exists entirely as HTML and JavaScript that uses CORS to talk to various APIs. GitHub's Gist API is accessible via CORS too, so it wouldn't take much more work to add a "save" button which writes out a new Gist after prompting for a personal access token. I prototyped that a bit here.
Notes on the new Claude analysis JavaScript code execution tool
Anthropic released a new feature for their Claude.ai consumer-facing chat bot interface today which they’re calling “the analysis tool”.
[... 918 words]Claude Artifact Runner (via) One of my least favourite things about Claude Artifacts (notes on how I use those here) is the way it defaults to writing code in React in a way that's difficult to reuse outside of Artifacts. I start most of my prompts with "no react" so that it will kick out regular HTML and JavaScript instead, which I can then copy out into my tools.simonwillison.net GitHub Pages repository.
It looks like Cláudio Silva has solved that problem. His claude-artifact-runner repo provides a skeleton of a React app that reflects the Artifacts environment - including bundling libraries such as Shadcn UI, Tailwind CSS, Lucide icons and Recharts that are included in that environment by default.
This means you can clone the repo, run npm install && npm run dev to start a development server, then copy and paste Artifacts directly from Claude into the src/artifact-component.tsx file and have them rendered instantly.
I tried it just now and it worked perfectly. I prompted:
Build me a cool artifact using Shadcn UI and Recharts around the theme of a Pelican secret society trying to take over Half Moon Bay
Then copied and pasted the resulting code into that file and it rendered the exact same thing that Claude had shown me in its own environment.
I tried running npm run build to create a built version of the application but I got some frustrating TypeScript errors - and I didn't want to make any edits to the code to fix them.
After poking around with the help of Claude I found this command which correctly built the application for me:
npx vite build
This created a dist/ directory containing an index.html file and assets/index-CSlCNAVi.css (46.22KB) and assets/index-f2XuS8JF.js (542.15KB) files - a bit heavy for my liking but they did correctly run the application when hosted through a python -m http.server localhost server.
I've often been building single-use apps with Claude Artifacts when I'm helping my children learn. For example here's one on visualizing fractions. [...] What's more surprising is that it is far easier to create an app on-demand than searching for an app in the app store that will do what I'm looking for. Searching for kids' learning apps is typically a nails-on-chalkboard painful experience because 95% of them are addictive garbage. And even if I find something usable, it can't match the fact that I can tell Claude what I want.
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]You can use text-wrap: balance; on icons. Neat CSS experiment from Terence Eden: the new text-wrap: balance CSS property is intended to help make text like headlines display without ugly wrapped single orphan words, but Terence points out it can be used for icons too:
This inspired me to investigate if the same technique could work for text based navigation elements. I used Claude to build this interactive prototype of a navigation bar that uses text-wrap: balance against a list of display: inline menu list items. It seems to work well!
My first attempt used display: inline-block which worked in Safari but failed in Firefox.
Notable limitation from that MDN article:
Because counting characters and balancing them across multiple lines is computationally expensive, this value is only supported for blocks of text spanning a limited number of lines (six or less for Chromium and ten or less for Firefox)
So it's fine for these navigation concepts but isn't something you can use for body text.
Video scraping: extracting JSON data from a 35 second screen capture for less than 1/10th of a cent
The other day I found myself needing to add up some numeric values that were scattered across twelve different emails.
[... 1,220 words]SVG to JPG/PNG. The latest in my ongoing series of interactive HTML and JavaScript tools written almost entirely by LLMs. This one lets you paste in (or open-from-file, or drag-onto-page) some SVG and then use that to render a JPEG or PNG image of your desired width.
I built this using Claude 3.5 Sonnet, initially as an Artifact and later in a code editor since some of the features (loading an example image and downloading the result) cannot run in the sandboxed iframe Artifact environment.
Here's the full transcript of the Claude conversation I used to build the tool, plus a few commits I later made by hand to further customize it.
The code itself is mostly quite simple. The most interesting part is how it renders the SVG to an image, which (simplified) looks like this:
// First extract the viewbox to get width/height
const svgElement = new DOMParser().parseFromString(
svgInput, 'image/svg+xml'
).documentElement;
let viewBox = svgElement.getAttribute('viewBox');
[, , width, height] = viewBox.split(' ').map(Number);
// Figure out the width/height of the output image
const newWidth = parseInt(widthInput.value) || 800;
const aspectRatio = width / height;
const newHeight = Math.round(newWidth / aspectRatio);
// Create off-screen canvas
const canvas = document.createElement('canvas');
canvas.width = newWidth;
canvas.height = newHeight;
// Draw SVG on canvas
const svgBlob = new Blob([svgInput], {type: 'image/svg+xml;charset=utf-8'});
const svgUrl = URL.createObjectURL(svgBlob);
const img = new Image();
const ctx = canvas.getContext('2d');
img.onload = function() {
ctx.drawImage(img, 0, 0, newWidth, newHeight);
URL.revokeObjectURL(svgUrl);
// Convert that to a JPEG
const imageDataUrl = canvas.toDataURL("image/jpeg");
const convertedImg = document.createElement('img');
convertedImg.src = imageDataUrl;
imageContainer.appendChild(convertedImg);
};
img.src = svgUrl;Here's the MDN explanation of that revokeObjectURL() method, which I hadn't seen before.
Call this method when you've finished using an object URL to let the browser know not to keep the reference to the file any longer.
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.
Notes on using LLMs for code
I was recently the guest on TWIML—the This Week in Machine Learning & AI podcast. Our episode is titled Supercharging Developer Productivity with ChatGPT and Claude with Simon Willison, and the focus of the conversation was the ways in which I use LLM tools in my day-to-day work as a software developer and product engineer.
[... 861 words]How Anthropic built Artifacts. Gergely Orosz interviews five members of Anthropic about how they built Artifacts on top of Claude with a small team in just three months.
The initial prototype used Streamlit, and the biggest challenge was building a robust sandbox to run the LLM-generated code in:
We use iFrame sandboxes with full-site process isolation. This approach has gotten robust over the years. This protects users' main Claude.ai browsing session from malicious artifacts. We also use strict Content Security Policies (CSPs) to enforce limited and controlled network access.
Artifacts were launched in general availability yesterday - previously you had to turn them on as a preview feature. Alex Albert has a 14 minute demo video up on Twitter showing the different forms of content they can create, including interactive HTML apps, Markdown, HTML, SVG, Mermaid diagrams and React Components.
Building a tool showing how Gemini Pro can return bounding boxes for objects in images
I was browsing through Google’s Gemini documentation while researching how different multi-model LLM APIs work when I stumbled across this note in the vision documentation:
[... 1,792 words]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.
Claude: You can now publish, share, and remix artifacts. Artifacts is the feature Anthropic released a few weeks ago to accompany Claude 3.5 Sonnet, allowing Claude to create interactive HTML+JavaScript tools in response to prompts.
This morning they added the ability to make those artifacts public and share links to them, which makes them even more useful!
Here's my box shadow playground from the other day, and an example page I requested demonstrating the Milligram CSS framework - Artifacts can load most code that is available via cdnjs so they're great for quickly trying out new libraries.
Box shadow CSS generator (via) Another example of a tiny personal tool I built using Claude 3.5 Sonnet and artifacts. In this case my prompt was:
CSS for a slight box shadow, build me a tool that helps me twiddle settings and preview them and copy and paste out the CSS
I changed my mind half way through typing the prompt and asked it for a custom tool, and it built me this!
Here's the full transcript - in a follow-up prompt I asked for help deploying it and it rewrote the tool to use <script type="text/babel"> and the babel-standalone library to add React JSX support directly in the browser - a bit of a hefty dependency (387KB compressed / 2.79MB total) but I think acceptable for this kind of one-off tool.
Being able to knock out tiny custom tools like this on a whim is a really interesting new capability. It's also a lot of fun!
Building search-based RAG using Claude, Datasette and Val Town
Retrieval Augmented Generation (RAG) is a technique for adding extra “knowledge” to systems built on LLMs, allowing them to answer questions against custom information not included in their training data. A common way to implement this is to take a question from a user, translate that into a set of search queries, run those against a search engine and then feed the results back into the LLM to generate an answer.
[... 3,372 words]Claude 3.5 Sonnet. Anthropic released a new model this morning, and I think it's likely now the single best available LLM. Claude 3 Opus was already mostly on-par with GPT-4o, and the new 3.5 Sonnet scores higher than Opus on almost all of Anthropic's internal evals.
It's also twice the speed and one fifth of the price of Opus (it's the same price as the previous Claude 3 Sonnet). To compare:
- gpt-4o: $5/million input tokens and $15/million output
- Claude 3.5 Sonnet: $3/million input, $15/million output
- Claude 3 Opus: $15/million input, $75/million output
Similar to Claude 3 Haiku then, which both under-cuts and out-performs OpenAI's GPT-3.5 model.
In addition to the new model, Anthropic also added a "artifacts" feature to their Claude web interface. The most exciting part of this is that any of the Claude models can now build and then render web pages and SPAs, directly in the Claude interface.
This means you can prompt them to e.g. "Build me a web app that teaches me about mandelbrot fractals, with interactive widgets" and they'll do exactly that - I tried that prompt on Claude 3.5 Sonnet earlier and the results were spectacular (video demo).
An unsurprising note at the end of the post:
To complete the Claude 3.5 model family, we’ll be releasing Claude 3.5 Haiku and Claude 3.5 Opus later this year.
If the pricing stays consistent with Claude 3, Claude 3.5 Haiku is going to be a very exciting model indeed.