{"slug": "sparqlite-sparql-1-1-inside-sqlite-written-in-rust", "title": "sparqlite: SPARQL 1.1 inside SQLite, written in Rust", "summary": "Simon Willison reported that Claude Code for web, run in \"Ultracode\" mode with dynamic subagent workflows, churned for over 12 hours on a single prompt and produced sparqlite, a SPARQL 1.1 implementation written in Rust as a SQLite extension. Willison's initial prompt contained an accidental typo (\"hit the delete rows directly\" for \"hit the rows directly\"), and a single follow-up prompt asked for READMEs in every crates/ folder plus a tutorial.md covering installation, SQLite CLI usage and SPARQL, along with a script populating a SQLite database with realistic example data. Willison said it is \"not remotely feasible to review the code that was produced here\" and questioned the value of a full SPARQL implementation created on a whim that he cannot or will not invest time to understand.", "body_md": "**Research:** [sparqlite: SPARQL 1.1 inside SQLite, written in Rust](https://github.com/simonw/research/tree/main/sqlite-sparql-rust#readme)\n\nThis research task is really an experiment in running Claude Code for web in \"Ultracode\" mode, as described in [Orchestrate subagents at scale with dynamic workflows](https://code.claude.com/docs/en/workflows) in the Claude Code documentation.\n\nWith Ultracode turned on, Claude Code makes aggressive use of dynamic workflows - it generates JavaScript that defines and coordinates a network of subagents to take on complex problems.\n\nMy initial prompt was this - I meant \"hit the rows directly\", the word \"delete\" was an accidental typo on my phone:\n\n`Write a SQLite extension in Rust that implants SPARQL and runs really fast because it can hit the delete rows directly`\n\nThis caused Claude Code for web to churn for over 12 hours. I checked in on its progress the next day and sent a single follow-up prompt when I noticed how many Rust crates it had built:\n\n`Every folder in the crates/ directory needs a README`\n\n`Include a tutorial.md teaching users how to install the extension and how to run it in the SQLite CLI and then teaching them SPARQL in addition to how to use the SQLite extension`\n\n`Include a script with the tutorial for populating a SQLite database with useful and realistic example data for that tutorial`\n\nThis project feels like next-level vibe coding - it's not remotely feasible to review the code that was produced here, and even following the documentation is a significant investment in work. I'm not entirely sure what to do with this - I appear to have a full SPARQL implementation in Rust inside SQLite now, but how valuable is that if I created it on a whim and can't (or won't) invest the necessary time to understand what it can do?\n\nTags: [rdf](https://simonwillison.net/tags/rdf), [semantic-web](https://simonwillison.net/tags/semantic-web), [sqlite](https://simonwillison.net/tags/sqlite), [ai](https://simonwillison.net/tags/ai), [rust](https://simonwillison.net/tags/rust), [generative-ai](https://simonwillison.net/tags/generative-ai), [llms](https://simonwillison.net/tags/llms), [coding-agents](https://simonwillison.net/tags/coding-agents), [claude-code](https://simonwillison.net/tags/claude-code)", "url": "https://wpnews.pro/news/sparqlite-sparql-1-1-inside-sqlite-written-in-rust", "canonical_source": "https://simonwillison.net/2026/Oct/16/sqlite-sparql-rust/", "published_at": "2026-10-16 01:58:00+00:00", "updated_at": "2026-10-21 16:42:10.954637+00:00", "lang": "en", "topics": ["ai-agents", "ai-tools", "generative-ai", "artificial-intelligence"], "entities": ["Simon Willison", "Claude Code", "sparqlite", "SQLite", "Rust", "SPARQL 1.1", "Anthropic"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/sparqlite-sparql-1-1-inside-sqlite-written-in-rust", "markdown": "https://wpnews.pro/news/sparqlite-sparql-1-1-inside-sqlite-written-in-rust.md", "text": "https://wpnews.pro/news/sparqlite-sparql-1-1-inside-sqlite-written-in-rust.txt", "jsonld": "https://wpnews.pro/news/sparqlite-sparql-1-1-inside-sqlite-written-in-rust.jsonld"}}