[15.0.0] - 2026-01-26 🖖🏻 "The Mind Meld Release" 🖖🏽

This is the biggest release of qsv yet thanks to many expert contributions from the community!

• @kulnor's deep expertise in statistics and data standards has been instrumental in enhancing qsv's data analysis capabilities across the entire qsv suite! His well-crafted issue reports, detailed design proposals, thorough testing and detailed documentation on top of our weekly mind-melds have vastly improved commands like frequency, stats, moarstats and describegpt. His contributions and advocacy have been invaluable and I've learned a lot from him.
• @ws-garcia's research on the Table Uniformity Method (TUM) - the algorithm behind the revamped sniff command will be the linchpin behind our upcoming next-gen CKAN harvester. Though it took a while, our implementation is now complete and achieves 99.55% accuracy on the W3C-CSVW test suite.
• @gurgeous' new color command contribution makes viewing CSVs in the terminal a joy! His attention to detail and design aesthetics have resulted in a command that is both functional and visually appealing, with more features on the way!
• If you look at the recent commit history, you can see I went on a Claude-bender over the holiday break 🤖. Collaborating heavily with @claude (running Opus 4.5) appropriately enough, to build up qsv's Generative AI capabilities in describegpt and its US Census-aware MCP server.

🌟 Major Features

An entire section courtesy of @kulnor's mind-melds.

Enhanced frequency Command

Powerful new filtering and display options:

• --no-float: Exclude Float columns from frequency analysis
• --pct-nulls: Include NULL values in percentage calculations
• --null-sorted: Sort NULL values with other entries (not at end)
• --no-other: Exclude the "Other" aggregation category
• --null-text: Customize the NULL display text
• --stats-filter: Luau-based column filtering using statistics
  • Filter columns based on any stats field (nullcount, cardinality, type, etc.)
  • Full Luau expression support for complex conditions
• Omit stats in JSON output when using --weight

Enhanced describegpt Command

AI-powered data description gets smarter. Now optimized to work with LM Studio and openai/gpt-oss-20b out-of-the-box:

• --frequency-options / --freq-opts: Pass options to underlying frequency command
• --enum-threshold Integration: Control enum constraint compilation thresholds
• file: Prefix Support: Load prompts from files with file:my_prompt.txt
• CLI Supersedes Environment Variables: Command-line options take precedence
• Updated LLM Base URLs: Current endpoints for major providers
• Robust Frequency Parsing: Better handling of frequency output formats
• QSV_TEST_DESCRIBEGPT: Environment variable for testing describegpt features

Enhanced stats Command

• File Metadata in JSON: JSON output now includes source file information
• Removed --dataset-stats: Statistics are now always populated (was optional flag)

Enhanced transpose Command

• --select Option: Select specific columns during transposition
  • Uses standard qsv select syntax
  • Filter columns before wide-to-long transformation

Revamped sniff Command

Complete overhaul of CSV sniffing capabilities with state-of-the-art detection algorithms:

• csv-nose Integration: Replaced qsv-sniffer with csv-nose for more robust and accurate detection using @ws-garcia's TUM algorithm
• Magika-Powered Inference: Feature-gated integration with Google's Magika for advanced, AI-powered file type detection
  • Inference labels for detected types
  • Confidence scores for type predictions
• 1-Based Field Numbering: More intuitive field indexing
• Robust Remote URLs: Improved handling of remote CSV sources
• 'Unknown' Fallback: Graceful handling of undetectable data types

NEW: color Command by @gurgeous

A vibrant new command for displaying CSVs as colorized, pretty-printed tables:

• Pretty Tables: Transform your CSVs into beautiful, readable terminal output
• Row Numbers (--row-numbers): Add line numbers for easy reference
• Custom Titles (--title): Add descriptive headers to your output
• Color Themes (--color): Choose from multiple color schemes
• Placeholder Support: Configurable placeholders for empty values
• Environment Variables: QSV_TERMWIDTH (max 1000) and QSV_FORCE_COLOR support
• Microoptimized: Fast rendering even for large datasets

Enhanced MCP Server

Major improvements to the Model Context Protocol server, making qsv even more AI-native:

Token Optimization 🚀

• 66-76% token reduction in tool definitions
• Removed redundant defaults and test_file fields from schemas
• Streamlined tool and prompts for efficient LLM consumption

Tool Lazy Loading

• Tool Search: Dynamically discover available tools and load them as required
• Expose-All-Tools Mode: Option to expose the complete tool catalog
• Universal --help: Even deeper help across all MCP-exposed commands if the Agent needs more information

Documentation & Integration

• Census Integration Guide: If you have the US Census' Official MCP Server installed, prime @claude to use it together with qsv efficiently to do deep research and analysis on data without overunning the context window.
• Updated Claude/MCP Documentation: Comprehensive Documentation
• qsv Prompts: Pre-built prompts for common data wrangling tasks
• SkillExecutor Unit Tests: Robust testing for skill execution

🏗️ Infrastructure & Quality

Testing

• Test suite expanded to 2,448 tests
• Comprehensive coverage for new MCP features
• SkillExecutor unit tests added

Documentation

• DeepWiki Badge: Added project documentation badge
• Emoji Legend: Added 🖥️ for UI commands, Luau logos for scripting
• COMMAND_DEPENDENCIES.md: New comprehensive command dependency documentation (by @kulnor)
• Detailed Examples: Enhanced examples for numerous commands, formatted to be both human and AI-readable
• Magika in Version Metadata: File type detection engine now shown in version info

📦 Dependencies

Major Updates

• reqwest: 0.12 → 0.13
• jsonschema: 0.39 → 0.40
• crossterm: 0.28.1 → 0.29.0
• csv-nose: 0.2.0 → 0.6.0
• sysinfo: 0.37.2 → 0.38.0
• rust_decimal: 1.39.0 → 1.40.0

Minor Updates

• zmij: 1.0.13 → 1.0.17
• flexi_logger: 0.31.7 → 0.31.8
• cmov: 0.4.3 → 0.4.5
• filetime: 0.2.26 → 0.2.27
• get-size2: 0.7.3 → 0.7.4
• hono: 4.11.3 → 4.11.4
• lodash: 4.17.21 → 4.17.23
• Polars: Latest upstream

CI/Actions

• actions/checkout: 4 → 6
• actions/setup-python: 6.1.0 → 6.2.0

Other

• Patched calamine fork with unreleased fixes
• MSRV: Rust 1.93

🌍 Environment Variables

New

• QSV_MCP_MAX_EXAMPLES: Maximum examples per MCP tool
• QSV_TERMWIDTH: Terminal width for color command (max 1000)
• QSV_FORCE_COLOR: Force color output
• QSV_TEST_DESCRIBEGPT: Enable describegpt testing mode

Updated

• QSV_PREAMBLE_ROWS: Enhanced preamble detection
• Various QSV_STATS_* and QSV_FORCE_* variables

Migration Notes

Breaking Changes

1. stats command: --dataset-stats option removed

   • Statistics are now always computed
   • No migration needed if not using this flag

2. sniff command: Field numbering changed to 1-based

   • Scripts parsing field numbers may need adjustment
   • More consistent with other qsv commands

Added

• feat: NEW color command for pretty-printed colorized tables by @gurgeous
• feat: frequency add --no-float option to exclude Float columns
• feat: frequency add --pct-nulls option for NULL percentage calculations
• feat: frequency add --null-sorted option for sorting NULL values
• feat: frequency add --no-other option to exclude Other category
• feat: frequency add --null-text option for custom NULL display
• feat: frequency add --stats-filter for Luau-based column filtering
• feat: describegpt add --frequency-options / --freq-opts option
• feat: describegpt add --enum-threshold integration
• feat: describegpt add file: prefix support for prompt files
• feat: stats add file metadata to JSON output
• feat: transpose add --select option for column selection
• feat: sniff integrate csv-nose for improved CSV detection
• feat: sniff add Magika-powered file type inference (feature-gated)
• feat: mcp add Tool Search capability
• feat: mcp add expose-all-tools mode
• feat: mcp add universal --help support
• feat: mcp add subcommand enum support
• feat: mcp add QSV_MCP_MAX_EXAMPLES configuration
• docs: add COMMAND_DEPENDENCIES.md by @kulnor
• docs: add DeepWiki badge
• docs: add emoji legend for UI commands and Luau
• docs: add Census integration guides for MCP
• docs: add detailed examples for sample, search, slice commands
• tests: add SkillExecutor unit tests

Changed

• perf: mcp reduce token consumption by 66-76%
• perf: mcp remove redundant defaults and test_file fields
• perf: color microoptimizations
• refactor: sniff replace qsv-sniffer with csv-nose
• refactor: sniff use 1-based field numbering
• refactor: sniff improve remote URL handling
• refactor: describegpt CLI options supersede environment variables
• refactor: describegpt update LLM base URLs
• refactor: stats remove --dataset-stats option (always populate)
• deps: bump reqwest from 0.12 to 0.13
• deps: bump jsonschema from 0.39 to 0.40
• deps: bump crossterm from 0.28.1 to 0.29.0
• deps: bump csv-nose from 0.2.0 to 0.5.0
• deps: bump sysinfo from 0.37.2 to 0.38.0
• deps: bump rust_decimal from 1.39.0 to 1.40.0
• deps: bump zmij from 1.0.13 to 1.0.17
• deps: bump flexi_logger from 0.31.7 to 0.31.8
• deps: use patched calamine fork with unreleased fixes
• deps: polars use latest upstream
• build: bump actions/checkout from 4 to 6
• build: bump actions/setup-python from 6.1.0 to 6.2.0
• build: bump MSRV to Rust 1.93
• ci: delete powerpc64 qsvpy workflow
• docs: update README with emoji legend
• docs: update Claude/MCP documentation
• bumped several indirect dependencies
• applied select clippy & Codacy suggestions
• applied several GH Copilot and Claude review suggestions
• bumped MSRV to Rust 1.93

Fixed

• fix: geocode --admin1 not supported with reversenow
• fix: validate jsonschema 0.39 API updates
• fix: to usage text comma separators
• fix: mcp rename --update-mcp-skill to --update-mcp-skills
• fix: mcp working directory passing
• fix: mcp Windows EPERM retry logic
• fix: mcp enum and py command handling
• fix: moarstats absolute output paths
• fix: describegpt robust frequency parsing

Removed

• removed: stats --dataset-stats option (statistics always computed)
• removed: clone count badge
• ci: removed powerpc64 qsvpy workflow

New Contributors

• @gurgeous made their first contribution in #3333

Full Changelog: 14.0.0...15.0.0