Simon Willison’s Weblog


4 items tagged “val-town”

Val Town provides a web interface for building, running and deploying server-side JavaScript apps.


Building search-based RAG using Claude, Datasette and Val Town

Visit 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.

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Val Vibes: Semantic search in Val Town. A neat case-study by JP Posma on how Val Town's developers can use Val Town Vals to build prototypes of new features that later make it into Val Town core.

This one explores building out semantic search against Vals using OpenAI embeddings and the PostgreSQL pgvector extension.

# 21st June 2024, 2:16 am / postgresql, ai, openai, embeddings, val-town

Val Town Newsletter 15 (via) I really like how Val Town founder Steve Krouse now accompanies their “what’s new” newsletter with a video tour of the new features. I’m seriously considering imitating this for my own projects.

# 15th February 2024, 4:26 pm / javascript, video, val-town

The first four Val Town runtimes (via) Val Town solves one of my favourite technical problems: how to run untrusted code in a safe sandbox. They're on their fourth iteration of this now, currently using a Node.js application that launches Deno sub-processes using the node-deno-vm npm package and runs code in those, taking advantage of the Deno sandboxing mechanism and terminating processes that take too long in order to protect against while(true) style attacks.

# 8th February 2024, 6:38 pm / javascript, nodejs, sandboxing, deno, tom-macwright, val-town