Chdb SQL
vemetric/vemetric
A skill your agent uses when the user wants to run SQL — especially analytical SQL — on local files (parquet/csv/json), URLs, S3 paths, or remote databases (Postgres, MySQL, MongoDB, ClickHouse…
Guide for writing performant ClickHouse queries in PostHog product code.
Install Writing Clickhouse Queries
$ npx skills add PostHog/posthog --skill writing-clickhouse-queries -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install PostHog/posthog writing-clickhouse-queries --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/PostHog/posthog.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/writing-clickhouse-queries .claude/skills/writing-clickhouse-queries && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "writing-clickhouse-queries" agent skill from https://github.com/PostHog/posthog/tree/master/.agents/skills/writing-clickhouse-queries into .claude/skills/writing-clickhouse-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-clickhouse-queries", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/PostHog/posthog/tree/master/.agents/skills/writing-clickhouse-queriesType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add PostHog/posthog --skill writing-clickhouse-queries -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install PostHog/posthog writing-clickhouse-queries --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PostHog/posthog.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/writing-clickhouse-queries .agents/skills/writing-clickhouse-queries && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "writing-clickhouse-queries" agent skill from https://github.com/PostHog/posthog/tree/master/.agents/skills/writing-clickhouse-queries into .agents/skills/writing-clickhouse-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-clickhouse-queries", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add PostHog/posthog --skill writing-clickhouse-queries -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install PostHog/posthog writing-clickhouse-queries --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PostHog/posthog.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/writing-clickhouse-queries .cursor/skills/writing-clickhouse-queries && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "writing-clickhouse-queries" agent skill from https://github.com/PostHog/posthog/tree/master/.agents/skills/writing-clickhouse-queries into .cursor/skills/writing-clickhouse-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-clickhouse-queries", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/PostHog/posthog.git --path .agents/skills/writing-clickhouse-queries--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add PostHog/posthog --skill writing-clickhouse-queries -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install PostHog/posthog writing-clickhouse-queries --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PostHog/posthog.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/writing-clickhouse-queries .gemini/skills/writing-clickhouse-queries && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "writing-clickhouse-queries" agent skill from https://github.com/PostHog/posthog/tree/master/.agents/skills/writing-clickhouse-queries into .gemini/skills/writing-clickhouse-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-clickhouse-queries", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install PostHog/posthog writing-clickhouse-queriesInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add PostHog/posthog --skill writing-clickhouse-queries -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/PostHog/posthog.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/writing-clickhouse-queries .github/skills/writing-clickhouse-queries && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "writing-clickhouse-queries" agent skill from https://github.com/PostHog/posthog/tree/master/.agents/skills/writing-clickhouse-queries into .github/skills/writing-clickhouse-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-clickhouse-queries", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add PostHog/posthog --skill writing-clickhouse-queries -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install PostHog/posthog writing-clickhouse-queries --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PostHog/posthog.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/writing-clickhouse-queries .opencode/skills/writing-clickhouse-queries && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "writing-clickhouse-queries" agent skill from https://github.com/PostHog/posthog/tree/master/.agents/skills/writing-clickhouse-queries into .opencode/skills/writing-clickhouse-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "writing-clickhouse-queries", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
writing-clickhouse-queries- GitHub stars
- 40k
- Token cost
- ~575 tokens
- SKILL.md length
- 170 words
- Files
- 1
- Skills in repo
- 254
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Guide for writing performant ClickHouse queries in PostHog product code.
- Writing HogQL query runners
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Designing a ClickHouse table for a new product
- Adding materialized columns
What it does
Writing Clickhouse Queries is an agent skill from PostHog/posthog, published by the product's own GitHub organization. Guide for writing performant ClickHouse queries in PostHog product code. Use when writing HogQL query runners, designing a ClickHouse table for a new product, adding materialized columns or skip indexes, or choosing a row ID format. For optimizing an existing query that is already too slow, use /optimizing-clickhouse-and-hogql-queries instead.
Its SKILL.md is about 580 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Databases, covering Data warehousing. It works with ClickHouse, PostHog and Python. The repository describes itself as: :hedgehog: PostHog is the leading platform for building self-driving products. Our developer tools – AI observability, analytics, session replay, flags, experiments, error…
When your agent uses it
- Writing HogQL query runners
- Designing a ClickHouse table for a new product
- Adding materialized columns
- Choosing a row ID format
Example prompts
- “/writing-clickhouse-queries”
Requirements
- Python 3
What it can do on your machine
Read from SKILL.md and the folder at commit c012c8d. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Writing Clickhouse Queries loads about 575 tokens when it runs. Until then it costs about 94 tokens; SKILL.md has 170 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 170 words (~575 tokens).
“If you're optimizing an existing query rather than writing a new one, this is the wrong skill. Use /optimizing-clickhouse-and-hogql-queries instead. That skill covers layer triage, smell scanning (FROM ... FINAL, JSONExtract over properties, missing skip indexes, self-joins, CTE blow-up), measurement…”
- name
- writing-clickhouse-queries
Files
Just SKILL.md in .agents/skills/writing-clickhouse-queries of PostHog/posthog.
Open the folder on GitHubat commit c012c8d
Used in 1 other repository
We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders. This page covers the copy in PostHog/posthog, which our catalogue first saw on October 8, 2026.
Compare with similar skills
Writing Clickhouse Queries next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Writing Clickhouse Queries this skillPostHog/posthog | 40k | — | ~575 | Automated safety check: Pass | Custom licence | |
| Chdb SQLvemetric/vemetric | 395 | 1 repos | ~1.2k | Automated safety check: Pass | Apache-2.0 | |
| Modelersidequery/sidemantic | 129 | — | ~4.2k | Automated safety check: Pass | Apache-2.0 | |
| Clickhouse Install Authjeremylongshore/tons-of-skills-marketplace | 2.8k | — | ~1.2k | Automated safety check: Notes | MIT | |
| Adapter Alignmentevloghq/evlog | 1.9k | — | ~1.3k | Automated safety check: Pass | MIT | |
| Chdb Datastorevemetric/vemetric | 395 | 2 repos | ~1.4k | Automated safety check: Pass | Apache-2.0 |
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Questions about Writing Clickhouse Queries
What does Writing Clickhouse Queries do?
Guide for writing performant ClickHouse queries in PostHog product code. Writing Clickhouse Queries is an agent skill from PostHog/posthog, published by the product's own GitHub organization. Guide for writing performant ClickHouse queries in PostHog product code.
When should I use Writing Clickhouse Queries?
Writing Clickhouse Queries fits situations like: writing HogQL query runners; designing a ClickHouse table for a new product; adding materialized columns; choosing a row ID format.
How do I install Writing Clickhouse Queries in Claude Code?
Run `npx skills add PostHog/posthog --skill writing-clickhouse-queries -a claude-code`. Or copy the skill folder (.agents/skills/writing-clickhouse-queries in PostHog/posthog) into .claude/skills/writing-clickhouse-queries in your project. Claude Code loads it when a task matches its description.
How do I install Writing Clickhouse Queries in Codex?
Run `npx skills add PostHog/posthog --skill writing-clickhouse-queries -a codex`. Or copy the skill folder (.agents/skills/writing-clickhouse-queries in PostHog/posthog) into .agents/skills/writing-clickhouse-queries in your project. Codex loads it when a task matches its description.
Can I use Writing Clickhouse Queries in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add PostHog/posthog --skill writing-clickhouse-queries -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/writing-clickhouse-queries, .gemini/skills/writing-clickhouse-queries, .github/skills/writing-clickhouse-queries and .opencode/skills/writing-clickhouse-queries in your project.
What does Writing Clickhouse Queries need to run?
SKILL.md names no scripts, command-line tools or credentials: Writing Clickhouse Queries is instructions for the agent only. Our summary lists: Python 3.
Does Writing Clickhouse Queries access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Writing Clickhouse Queries safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Writing Clickhouse Queries use?
Writing Clickhouse Queries has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Writing Clickhouse Queries use?
About 575 tokens (SKILL.md is roughly 2.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Writing Clickhouse Queries?
Skills that share tags, products or a category with Writing Clickhouse Queries: Chdb SQL (vemetric/vemetric, 395 stars), Modeler (sidequery/sidemantic, 129 stars), Clickhouse Install Auth (jeremylongshore/tons-of-skills-marketplace, 2.8k stars) and Adapter Alignment (evloghq/evlog, 1.9k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Writing Clickhouse Queries?
PostHog (a GitHub organization, an official publisher) maintains it in PostHog/posthog, which has 40,209 GitHub stars. The repository holds 254 skills in this directory. The repository was last updated on October 10, 2026.
Source: PostHog/posthog on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.