DuckDB released a plugin that lets Claude Code query data files directly using SQL instead of writing Python scripts, making it faster and more accurate. The plugin handles everything from local CSVs to remote cloud storage and spatial data, with Claude automatically picking the right tool based on what you ask.

• Claude can now run SQL queries against any file format (CSV, Parquet, JSON, Excel, etc.) on disk or in cloud storage, getting exact answers instead of guessing column names
• The plugin includes specialized skills for S3/GCS exploration, spatial queries (distances, nearest neighbors), searching DuckDB docs, and recalling decisions from past sessions
• When a query fails, Claude reads the error message and retries with corrected SQL automatically, creating a two-layer conversation (natural language with you, SQL with DuckDB)

OpenAI’s data productivity team built Kepler, an AI agent that understands their data platform context and writes iterative SQL to answer complex data questions. It handles table discovery, query refinement, follow-up prompts and even visualizations, cutting analysis time and reducing errors.

• OpenAI built Kepler, an internal AI agent that writes iterative SQL to answer data questions across 70,000 datasets and 600 petabytes daily, deployed via Slack, IDEs, or web UI
• It doesn't just query once—it discovers tables, refines CTEs, verifies numbers against dashboards/Notion, and proposes hypotheses (e.g., duplicate logging) for anomalies like a WAU spike
• Memory for self-learning plus rigorous evals let it improve over time without regressing
• Rolled out to 80% of the company, turning multi-engineer, multi-hour investigations into minutes

Hex built a suite of analytical evals to test data-analysis models and found Claude Fable 5 outperforms its Opus 4.x predecessors by 10–15%, nailing both semantically modeled and raw-data tasks with fewer mistakes. They’ve also designed a tougher “Frontier” benchmark for long-horizon, open-ended scenarios, where Fable 5’s careful assumptions and cross-checks boost its pass rate to around 58%.

• Claude Fable 5 beats Opus 4.7 by 10-15 points on Hex's core benchmarks, scoring 93%+ on Analytical Hard/Semantically Modeled tests and 65% on Semantically Unmodeled tasks, versus prior Opus versions' single-digit gains
• Fable's advantage comes from following a "golden workflow" (starting in the semantic layer, cross-checking raw SQL) and transparently stating assumptions, which lets it catch errors like a cents-for-dollars mistake that Opus misses
• On Hex's new "Frontier" benchmark for long-horizon, open-ended tasks, Fable at Max Effort hits 58% pass rate, notably outperforming other setups

The author shares their shift from using Excel and Google Sheets to DuckDB and SQL for handling CSV files, highlighting the efficiency of querying data directly. They discuss the benefits of using SQL for data manipulation and invite readers to share their own CSV handling tips.

• DuckDB lets you run SQL directly on CSV files (joins, window functions, dedup queries) without importing them into Excel/Sheets first
• You can query CSVs from URLs or cloud storage like S3 directly, and export results straight back to CSV
• Several users find SQL queries more intuitive than replicating the same logic with spreadsheet formulas or pivot tables
• Some commenters mix in Parquet files and other extensions alongside DuckDB to further speed up ad-hoc analysis