system-tables-reference

A reference listing exact column names for commonly queried system tables. System tables are built-in database tables that describe activity, storage, settings, users, and other internal state.

In plain words
What is it for?
Use it before writing SQL against tables for processes, queries, parts, merges, mutations, replicas, disks, settings, users and grants, or metrics.
Why use it?
It helps avoid incorrect SQL when inspecting database internals and indicates when a dedicated tool is preferable.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/chmonitor/chmonitor/system-tables-reference
Any agent
npx skills add chmonitor/chmonitor --skill system-tables-reference
Clone the repo
git clone --depth 1 https://github.com/chmonitor/chmonitor

Made for: Claude Code, Codex.

Per session 66 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,258 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00066 $0.02258
Opus 5 $0.00033 $0.01129
Sonnet 5 $0.00013 $0.00452
Haiku 4.5 $0.00007 $0.00226

Measured 2d ago against content hash b876a64a2501, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

system-tables-reference scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/system-tables-reference/SKILL.md · 194 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 194 lines · 66 tokens per session scan A b876a64a2501

Subscribe to this mod's changes

system-tables-reference is a skill published in the GitHub repository chmonitor/chmonitor (285 stars, last pushed 5d ago), licensed GPL-3.0. It adds 66 tokens to every session and 2,258 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.