Simon Willison’s Weblog

Golden Gate Claude. This is absurdly fun and weird. Anthropic's recent LLM interpretability research gave them the ability to locate features within the opaque blob of their Sonnet model and boost the weight of those features during inference.

For a limited time only they're serving a "Golden Gate Claude" model which has the feature for the Golden Gate Bridge boosted. No matter what question you ask it the Golden Gate Bridge is likely to be involved in the answer in some way. Click the little bridge icon in the Claude UI to give it a go.

I asked for names for a pet pelican and the first one it offered was this:

Golden Gate - This iconic bridge name would be a fitting moniker for the pelican with its striking orange color and beautiful suspension cables.

And from a recipe for chocolate covered pretzels:

Gently wipe any fog away and pour the warm chocolate mixture over the bridge/brick combination. Allow to air dry, and the bridge will remain accessible for pedestrians to walk along it.

UPDATE: I think the experimental model is no longer available, approximately 24 hours after release. We'll miss you, Golden Gate Claude. # 24th May 2024, 8:17 am

Scaling Monosemanticity: Extracting Interpretable Features from Claude 3 Sonnet (via) Big advances in the field of LLM interpretability from Anthropic, who managed to extract millions of understandable features from their production Claude 3 Sonnet model (the mid-point between the inexpensive Haiku and the GPT-4-class Opus).

Some delightful snippets in here such as this one:

We also find a variety of features related to sycophancy, such as an empathy / “yeah, me too” feature 34M/19922975, a sycophantic praise feature 1M/847723, and a sarcastic praise feature 34M/19415708.

timpaul/form-extractor-prototype (via) Tim Paul, Head of Interaction Design at the UK’s Government Digital Service, published this brilliant prototype built on top of Claude 3 Opus.

The video shows what it can do. Give it an image of a form and it will extract the form fields and use them to create a GDS-style multi-page interactive form, using their GOV.UK Forms design system and govuk-frontend npm package.

It works for both hand-drawn napkin illustrations and images of existing paper forms.

The bulk of the prompting logic is the schema definition in data/extract-form-questions.json

I’m always excited to see applications built on LLMs that go beyond the chatbot UI. This is a great example of exactly that. # 22nd April 2024, 10:01 pm

A solid pattern to build LLM Applications (feat. Claude) (via) Hrishi Olickel is one of my favourite prompt whisperers. In this YouTube video he walks through his process for building quick interactive applications with the assistance of Claude 3, spinning up an app that analyzes his meeting transcripts to extract participants and mentioned organisations, then presents a UI for exploring the results built with Next.js and shadcn/ui.

An interesting tip I got from this: use the weakest, not the strongest models to iterate on your prompts. If you figure out patterns that work well with Claude 3 Haiku they will have a significantly lower error rate with Sonnet or Opus. The speed of the weaker models also means you can iterate much faster, and worry less about the cost of your experiments. # 9th April 2024, 6:39 pm

The lifecycle of a code AI completion (via) Philipp Spiess provides a deep dive into how Sourcegraph’s Cody code completion assistant works. Lots of fascinating details in here:

“One interesting learning was that if a user is willing to wait longer for a multi-line request, it usually is worth it to increase latency slightly in favor of quality. For our production setup this means we use a more complex language model for multi-line completions than we do for single-line completions.”

This article is from October 2023 and talks about Claude Instant. The code for Cody is open source so I checked to see if they have switched to Haiku yet and found a commit from March 25th that adds Haiku as an A/B test. # 7th April 2024, 7:37 pm

The cost of AI reasoning over time (via) Karina Nguyen from Anthropic provides a fascinating visualization illustrating the cost of different levels of LLM over the past few years, plotting their cost-per-token against their scores on the MMLU benchmark.

Claude 3 Haiku currently occupies the lowest cost to score ratio, over on the lower right hand side of the chart. # 4th April 2024, 12:51 pm

“The king is dead”—Claude 3 surpasses GPT-4 on Chatbot Arena for the first time. I’m quoted in this piece by Benj Edwards for Ars Technica:

“For the first time, the best available models—Opus for advanced tasks, Haiku for cost and efficiency—are from a vendor that isn’t OpenAI. That’s reassuring—we all benefit from a diversity of top vendors in this space. But GPT-4 is over a year old at this point, and it took that year for anyone else to catch up.” # 27th March 2024, 4:58 pm

Semgrep: AutoFixes using LLMs (via) semgrep is a really neat tool for semantic grep against source code—you can give it a pattern like “log.$A(...)” to match all forms of log.warning(...) / log.error(...) etc.

Ilia Choly built semgrepx— xargs for semgrep—and here shows how it can be used along with my llm CLI tool to execute code replacements against matches by passing them through an LLM such as Claude 3 Opus. # 26th March 2024, 12:51 am

llm-claude-3 0.3. Anthropic released Claude 3 Haiku today, their least expensive model: $0.25/million tokens of input, $1.25/million of output (GPT-3.5 Turbo is $0.50/$1.50). Unlike GPT-3.5 Haiku also supports image inputs.

I just released a minor update to my llm-claude-3 LLM plugin adding support for the new model. # 13th March 2024, 9:18 pm

The Claude 3 system prompt, explained. Anthropic research scientist Amanda Askell provides a detailed breakdown of the Claude 3 system prompt in a Twitter thread.

This is some fascinating prompt engineering. It’s also great to see an LLM provider proudly documenting their system prompt, rather than treating it as a hidden implementation detail.

The prompt is pretty succinct. The three most interesting paragraphs:

“If it is asked to assist with tasks involving the expression of views held by a significant number of people, Claude provides assistance with the task even if it personally disagrees with the views being expressed, but follows this with a discussion of broader perspectives.

Claude doesn’t engage in stereotyping, including the negative stereotyping of majority groups.

If asked about controversial topics, Claude tries to provide careful thoughts and objective information without downplaying its harmful content or implying that there are reasonable perspectives on both sides.” # 7th March 2024, 1:16 am

llm-claude-3. I built a new plugin for LLM—my command-line tool and Python library for interacting with Large Language Models—which adds support for the new Claude 3 models from Anthropic. # 4th March 2024, 6:46 pm

The new Claude 3 model family from Anthropic. Claude 3 is out, and comes in three sizes: Opus (the largest), Sonnet and Haiku.

Claude 3 Opus has self-reported benchmark scores that consistently beat GPT-4. This is a really big deal: in the 12+ months since the GPT-4 release no other model has consistently beat it in this way. It’s exciting to finally see that milestone reached by another research group.

The pricing model here is also really interesting. Prices here are per-million-input-tokens / per-million-output-tokens:

Claude 3 Opus: $15 / $75
Claude 3 Sonnet: $3 / $15
Claude 3 Haiku: $0.25 / $1.25

All three models have a 200,000 length context window and support image input in addition to text.

Compare with today’s OpenAI prices:

GPT-4 Turbo (128K): $10 / $30
GPT-4 8K: $30 / $60
GPT-4 32K: $60 / $120
GPT-3.5 Turbo: $0.50 / $1.50

So Opus pricing is comparable with GPT-4, more than GPT-4 Turbo and significantly cheaper than GPT-4 32K... Sonnet is cheaper than all of the GPT-4 models (including GPT-4 Turbo), and Haiku (which has not yet been released to the Claude API) will be cheaper even than GPT-3.5 Turbo.

It will be interesting to see if OpenAI respond with their own price reductions. # 4th March 2024, 6:34 pm