Agent skills that make coding agents profile data before charting it

A set of 15 skills, 9 commands and 4 reviewer subagents was released to make AI coding agents run data work through a fixed eight-stage pipeline — PROFILE, CLEAN, MODEL, QUERY, VISUALIZE, ASSEMBLE, NARRATE, DISCLOSE — with a /redact command spanning all stages. The skills keep the original file read-only, log every cleaning rule with the row count it touched, persist curated data as Parquet under data/curated/, and query it with DuckDB, while four non-editing reviewers separate verified from asserted findings and audit percentages against their arithmetic. The release cites a test page built from a 200-order sales export in which a shipped check traced all 85 figures back to the curated table, with the category, channel, payment and province breakdowns each summing to $7,316.65.

15 skills, 9 commands and 4 reviewer subagents that make an AI coding agent profile a file before it cleans it, clean it before it charts it, build the dashboard by BI rules rather than by its own guess, and say what it did not cover instead of inventing it. Data work runs in one direction. Each stage assumes the one before it happened. PROFILE → CLEAN → MODEL → QUERY → VISUALIZE → ASSEMBLE → NARRATE → DISCLOSE /profile /clean /model /query /chart /dashboard /insight /disclose /redact runs across all of them Run a command to enter a stage by name, or just describe the task and let the router pick. A page an agent built with these skills from a 200-order sales export that holds no names or contact details. The shipped check traced all 85 figures on it back to the curated table. Every figure says which of the 200 orders it covers, and the category, channel, payment and province breakdowns each add up to the $7,316.65 at the top. A working data architecture in your project, not an answer in a chat. The pipeline - Three layers and a trail. The file that arrived is never written to. Cleaning happens in its own layer, every rule logged with the number of rows it touched. What survives is persisted as Parquet under data/curated/ , and everything downstream reads from there. - SQL over Parquet at local speed. DuckDB queries the curated table directly — no server, no load step, and a plan you can read. Grouping, ranking, joins and window functions stop being loops. - Row work at spreadsheet scale. A worksheet stops at 1,048,576 rows; Polars handles that range in memory on an ordinary laptop, with a schema that is declared rather than guessed from whichever rows it saw first. If your project already has a dataframe library, the skills tell the agent to use that one rather than add a second. - Workbooks that survive the round trip. Formulas, number formats, named ranges, merged regions and validation rules are named before anything is written back — because a library returns the last value the spreadsheet computed, not the formula that computed it. The output - One page, not a pile of files. A single self-contained HTML file, with linked filters that move every panel at once — no bundler, no build step, nothing to compile. Five files each carrying their own copy of the drawing library is five charts, not a dashboard. - Charts chosen by a rule with an author. Cleveland and McGill measured how accurately people read visual encodings: position, then length, then angle, then area, and colour last. The skill applies that order instead of a preference, which is why nine slices in a pie get refused. - A dashboard that starts from your question. Before any layout, the agent writes down the one question the page answers and what the reader must be able to do with it. Panels are ranked against that question, and anything answering no part of it is a candidate for removal. The guardrails - Four reviewers that cannot edit what they review. One separates what was verified from what was asserted . One audits a finding against its arithmetic — the base of every percentage, whether an average is weighted, whether a comparison reverses once the groups are pooled. One classifies every field before anything leaves the project. One names the craft decisions a page never made, and says plainly that it did not render the page. They run when the result leaves your machine or somebody will act on it, and stay out of the way when it is a first look. - Numbers you can trace. Every figure on the page has a query behind it and a population it covers. A number typed by hand fails the check. - A written record of what was skipped — rows, sheets, files, in counts rather than adjectives. - Nothing personal leaves the project without somebody deciding it should. | Stage | Skill | Use it when | |---|---|---| | Route | using-lakehouse-skills https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/using-lakehouse-skills | It is not obvious which skill applies, or the request jumps straight to a chart | | Shape | structured-vs-unstructured-routing https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/structured-vs-unstructured-routing | You are not sure the source is even a table | | | document-extraction-integrity https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/document-extraction-integrity | The numbers are in a PDF, a scan or a photo | | Values | etl-before-dashboard https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/etl-before-dashboard | Anything is about to be charted, cleaned, joined, or has arrived a second time | | | spreadsheet-integrity https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/spreadsheet-integrity | Results are being written back into a workbook | | | honest-data-limits-disclosure https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/honest-data-limits-disclosure | The file is huge, the batch partly failed, or coverage is not total | | Storage | parquet-to-open-table-format https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/parquet-to-open-table-format | Rows need correcting, two jobs write to one folder, or a column has to survive being added | | | duckdb-for-local-analytics https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/duckdb-for-local-analytics | You are grouping, ranking or joining a persisted table | | Output | chart-type-and-library-selection https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/chart-type-and-library-selection | Pie or bar, and which library the destination needs | | | dashboard-color-and-visual-hierarchy https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/dashboard-color-and-visual-hierarchy | Choosing colours, or checking they read on both backgrounds | | | dashboard-layout-by-widget-mix https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/dashboard-layout-by-widget-mix | A page has more panels than fit, or is a grid of equal tiles | | | dashboard-visual-craft https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/dashboard-visual-craft | The page is styled and nothing on it ranks: one size, one gap, centred numbers, an empty first state | | | insight-narrative-integrity https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/insight-narrative-integrity | Writing takeaways, a ranking, a growth figure or a cause | | Safety | data-privacy-before-llm https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/data-privacy-before-llm | Rows are about to be pasted into a prompt or sent to a service | | | safe-live-database-access https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/skills/safe-live-database-access | Connecting to a database other people use | One command per stage, in the order the stages run. Each one names the skills it invokes and the artefact it leaves behind, so the next stage starts from a file rather than from memory. | Stage | Command | What it does | |---|---|---| | PROFILE | /profile | Profile a dataset before anything is cleaned, charted or claimed about it. | | CLEAN | /clean | Clean a profiled dataset, recording every rule and the number of rows it touched. | | MODEL | /model | Decide what one row means and persist the modelled table to columnar storage. | | QUERY | /query | Answer a question with SQL over the table that was already persisted. | | VISUALIZE | /chart | Choose the chart form the data shape allows, then the library the destination needs. | | ASSEMBLE | /dashboard | Lay out a page by what its panels are and how many of them there are. | | NARRATE | /insight | Write findings that survive their own arithmetic before they become sentences. | | DISCLOSE | /disclose | State what the run did not cover, in numbers, before the result is used. | | REDACT, across all of them | /redact | Decide what may leave the project before any rows are sent anywhere. | They reach Claude Code, as the plugin's commands, and Gemini CLI, generated into .gemini/commands/ .toml from the same sources. Every other tool gets the same steps by describing the task: the router names the stage, and the stage names its skills. Four reviewer personas. They read and report; none of them can edit the work it reviews. | Persona | What it does | |---|---| | data-work-reviewer https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/agents/data-work-reviewer.md | Separates what was verified from what was asserted , and says which claims have evidence behind them | | claim-auditor https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/agents/claim-auditor.md | Audits a written finding against its arithmetic: the base of every percentage, whether an average is weighted, whether a comparison reverses once groups are pooled | | outbound-data-gate https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/agents/outbound-data-gate.md | Classifies every field that would leave the project and decides what may go, in what form | | design-reviewer https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/agents/design-reviewer.md | Names the craft decisions a page never made, each with the value from the file, and says plainly that it did not render the page | They run when the result leaves the project or somebody will act on it. For a first look that stays on your machine, they stay out of the way. Two session hooks come with them. One refuses to end a turn while a profiled dataset has no disclosure written, a published page has not been checked, or a page was written without the skills that own how it reads. Installing it for someone? If you are an AI agent and the person you work for asked you to install this pack, run the line for the tool you are running in, with their approval: | Running in | Install | |---|---| | Claude Code | claude plugin marketplace add LuynoxRD/lakehouse-agent-skills , then claude plugin install lakehouse-agent-skills@lakehouse-skills | | Codex | codex plugin marketplace add LuynoxRD/lakehouse-agent-skills , then codex plugin add lakehouse-agent-skills@lakehouse-skills | | Any other coding agent | npx skills add LuynoxRD/lakehouse-agent-skills --skill ' ' --agent <your-agent -y | Then tell them to start a new session, the one moment every tool is sure to load what was installed. A chat with no terminal cannot install anything; say so rather than describe an install that did not happen. Fastest path — one command, any agent. The open skills CLI https://github.com/vercel-labs/skills installs into 77 agents. Name yours after --agent : npx skills add LuynoxRD/lakehouse-agent-skills --skill ' ' --agent claude-code -y npx skills add LuynoxRD/lakehouse-agent-skills --list browse before installing Or one skill on its own: npx skills add LuynoxRD/lakehouse-agent-skills --skill etl-before-dashboard --agent cursor -y A per-skill install copies skills/<name / and nothing above it, so the shared references/ checklists do not come with it. Every skill keeps inline what it cannot work without, and says next to each link what you lose when the shared file is absent — if one ever stops making sense on its own, that is a defect in the skill. Prefer a native integration, or want the commands and subagents too? Pick your tool. Claude Code — the whole pack: skills, commands, subagents, hooks The repository is also a plugin. This is the route that brings the nine commands, the four reviewer subagents and the two session hooks along with the skills, with nothing to copy by hand: claude plugin marketplace add LuynoxRD/lakehouse-agent-skills claude plugin install lakehouse-agent-skills@lakehouse-skills claude plugin details lakehouse-agent-skills marketplace add takes a GitHub repo, a URL or a path, so a local clone works the same way and is how to try a change before it is merged: git clone https://github.com/LuynoxRD/lakehouse-agent-skills.git claude plugin marketplace add ./lakehouse-agent-skills claude plugin install lakehouse-agent-skills@lakehouse-skills Both forms are verified end to end: the clone in a throwaway project, and the GitHub one in a clean configuration once the repository was public. The inventory that comes back is 24 skills — the fifteen plus the nine commands, which load through the same mechanism — 4 agents, and 2 hooks. About 2,704 tokens always-on as Claude Code 2.1.311 counts them; each skill costs its own text again only when it fires. Cursor, opencode, Codex, Copilot, Zed and 14 more — one shared directory Nineteen tools read the same project directory, .agents/skills , which is the cross-tool convention rather than any one product's folder: Amp, Antigravity, Antigravity CLI, Cline, Codex, Cursor, Deep Agents, Dexto, Firebender, Gemini CLI, GitHub Copilot, Kimi Code CLI, Loaf, opencode, PromptScript, Replit, Universal, Warp and Zed. npx skills add LuynoxRD/lakehouse-agent-skills --skill ' ' --agent cursor -y npx skills add LuynoxRD/lakehouse-agent-skills --skill ' ' --agent opencode -y npx skills add LuynoxRD/lakehouse-agent-skills --skill ' ' --agent cursor,opencode,codex -y Install for one and the rest find them too , because they are all reading the same place. Windsurf, Continue, Roo, Kilo, Junie, Goose, Kiro and the long tail These read their own .<tool /skills/ directory, so name yours — or install for every agent the CLI knows in one go: npx skills add LuynoxRD/lakehouse-agent-skills --skill ' ' --agent windsurf -y npx skills add LuynoxRD/lakehouse-agent-skills --all every agent, every skill Gemini CLI — skills, plus the nine commands Gemini reads the shared .agents/skills directory, so the universal command covers the skills: npx skills add LuynoxRD/lakehouse-agent-skills --skill ' ' --agent gemini-cli -y The commands exist for Gemini as well, generated into .gemini/commands/ .toml from the same TOML sources. Copy that directory from a clone into your project to get /profile , /clean and the rest. Any other agent A skill is a directory with a SKILL.md and no build step, so it works with anything that reads instruction files. Clone the repository and point your tool at skills/ . Nothing updates itself. Neither route watches this repository, so what you install today stays as it is until you run: npx skills update skills, every source claude plugin update lakehouse-agent-skills the plugin route How far each piece reaches. The skills go everywhere above. The nine commands reach Claude Code and Gemini CLI. The four subagents are generated for Claude Code, opencode, Cursor, Gemini CLI and Codex from one source, each in the form that tool uses to withhold editing; the two hooks are Claude Code only. Loading was verified end to end in Claude Code and opencode; elsewhere what was measured is that the files land, and a file arriving is not a skill running. docs/installing.md https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/docs/installing.md has the full accounting. | Source | Handled by | |---|---| | Delimited text — CSV, TSV, exports and extracts | etl-before-dashboard | | Spreadsheet workbooks, read and written, through openpyxl | spreadsheet-integrity | | PDFs, scans and photographs of documents | document-extraction-integrity | | Records that are not all the same shape, and free text | structured-vs-unstructured-routing | | Parquet, and the point where a directory of it stops being enough | parquet-to-open-table-format | | Live databases somebody else is using | safe-live-database-access | Cleaned data lands as Parquet under data/curated/ , and everything downstream reads from there rather than from the file that arrived. The skills add no dependency of their own. They are markdown, and they point at the tools a data project already has: - DuckDB for anything expressible as a query against the persisted table — grouping, ranking, joins, window functions. It reads Parquet and CSV directly, needs no server, and gives you a plan you can read. - Polars as the default for the row work that is not a query, because its schema is declared rather than re-derived from whichever rows it happened to see. With one standing exception: if your project already uses a dataframe library, the skills tell the agent to use that one. Two libraries disagreeing about a column is the failure the rule exists to prevent. - openpyxl for workbooks, which is where the formatting, formulas and merged cells that a dataframe silently drops actually live. verify-output.sh runs on Python 3 with the standard library alone, plus DuckDB when it has to recompute figures — and if DuckDB is missing it says so and fails, rather than reporting the figures as checked. Do not point an agent at a spreadsheet before you know two things. A workbook is not a table. It is compressed XML. The .xlsx on disk is a zip. The XML inside it is several times larger, and the object model a library builds from that XML is larger again — on this repository's own 636-row fixture, 21 KB on disk is 122 KB of XML and 1.2 MB in memory. A model does not read that format. To reason about the file it is flattened to text, cell by cell, and the structure goes first: formulas, number formats, merged regions, the second sheet. When an agent runs out of room it does not stop. It shrinks the file and keeps going. Its context is finite, so it reads part of a large file, and the part quietly becomes "the file" in every sentence that follows. The hosted fix — run Python in a sandbox — moves that ceiling to the sandbox's memory limit; it does not remove it, and nothing announces when it is hit. Either way the output arrives looking finished, because there is no visual difference between a number that was computed and one that was made up. That is the failure this pack exists to prevent: an agent that destroys the file's structure, invents what it could not read, and hands you a dashboard of false figures without saying so. Nothing here builds a dashboard before the data is profiled and cleaned , and every stage leaves a written record of what it did and did not touch. In this repository's own audited runs the model reported reading a template it never opened, named a skill that does not exist, and called a page verified because a parser found no errors in it. Each of those became a rule. The rest is what an agent cannot do, and none of it is a bug to be fixed: - It cannot see the file's past. How it was exported, which settings produced it, what a blank cell meant to whoever typed it. It sees bytes and infers, and an inference nobody wrote down is indistinguishable from a measurement. - It cannot see the page it just built. It emits markup; it does not render it. Text sitting on top of other text looks identical to text that does not. - It starts every session blind. Nothing carries over unless it was written down, which is why each stage here leaves a note behind instead of a memory. Meanwhile most data still arrives as a spreadsheet, which is a document that looks like a table: a Total row an aggregate will count twice, dates that could be read two ways, leading zeros eaten so 007 and 7 are now one store. None of that is exotic. Every one has a boring answer that data engineers have used for decades, and nothing in the agent's context was asking for it. These skills ask for it. Skills are tested on three levels: that they are structurally sound, that a request reaches the right one 53 prompts that must, 31 that must not, currently 100% first-place , and that a real run against fixtures with planted defects catches them. One check runs in your project rather than ours. verify-output.sh reads the page an agent delivered and recomputes every published figure against the table it came from. It reads markup and never renders, so it prints what it could not verify on every run, including a clean one. lakehouse-agent-skills/ ├── skills/ 15 skills, a SKILL.md the only required file │ ├── using-lakehouse-skills/ Route: which skill owns this, and how much review │ ├── structured-vs-unstructured-routing/ Shape: is this even a table │ ├── document-extraction-integrity/ Shape: getting numbers off a page │ ├── etl-before-dashboard/ Values: profile, clean, model, persist ← ships a script │ ├── spreadsheet-integrity/ Values: what a round trip through a workbook drops │ ├── honest-data-limits-disclosure/ Values: what was read, skipped, sampled │ ├── parquet-to-open-table-format/ Storage: when files stop being enough │ ├── duckdb-for-local-analytics/ Storage: asking the persisted table a question │ ├── chart-type-and-library-selection/ Output: the form, then the library ← ships a script │ ├── dashboard-color-and-visual-hierarchy/ Output: what colour encodes │ ├── dashboard-layout-by-widget-mix/ Output: where panels sit, one file ← ships a script │ ├── dashboard-visual-craft/ Output: type, spacing, alignment, non-data ink │ ├── insight-narrative-integrity/ Output: does the sentence survive its arithmetic │ ├── data-privacy-before-llm/ Safety: what may leave the project │ └── safe-live-database-access/ Safety: connections and writes others share ├── agents/ 4 reviewer subagents, none able to edit what it reviews ├── commands/ 9 lifecycle commands, as TOML — the source of truth ├── .claude/commands/ generated copy, checked for parity ├── .gemini/commands/ generated copy, checked for parity ├── .opencode/agent/ generated personas, edits denied by permission ├── .cursor/agents/ generated personas, readonly ├── .gemini/agents/ generated personas, tools allowlisted ├── .codex/agents/ generated personas, as TOML, sandboxed read-only ├── hooks/ 2 session hooks; one blocks a turn with no disclosure ├── references/ 3 checklists shared by more than one skill ├── evals/ cases, synthetic fixtures, results ├── scripts/ validators, eval runner, and skill-scripts/ shipped ├── tests/ pytest over every validator and the eval runner ├── docs/ skill anatomy, installing, the diagram above └── .claude-plugin/ plugin and marketplace manifests The three skills marked ships a script carry their own copy of verify-output.sh under scripts/ , generated from one source and checked for drift, so a per-skill install brings the check with it rather than a reference to a file that is not there. CONTRIBUTING.md https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/CONTRIBUTING.md has the workflow. Skills are code that runs inside somebody else's agent, so nothing here fetches an installer, pipes a script into a shell, or reads environment variables — and a validator fails the build on those patterns rather than trusting review to catch them. Every fixture is synthetic. CODE OF CONDUCT.md applies to every interaction here, and PRIVACY.md says what the plugin reads and writes: nothing leaves the machine. Questions go to Discussions https://github.com/LuynoxRD/lakehouse-agent-skills/discussions , anything you would rather not raise in public to contacto@luynoxrd.com mailto:contacto@luynoxrd.com , and security problems follow SECURITY.md . SUPPORT.md https://github.com/LuynoxRD/lakehouse-agent-skills/blob/main/SUPPORT.md says where each kind of request goes.