querying-local-postgres

querying-local-postgres is a skill for Claude Code, Codex from PostHog/posthog-foss. It costs 79 tokens per session (2,560 once invoked), scanned A, original, MIT.

A read-only tool for running SQL queries against a local PostgreSQL database. PostgreSQL is a database system; read-only means the queries cannot change its data.

In plain words
What is it for?
Use it to inspect tables, debug rows and constraints, check migrations, find duplicates, and examine the planned or measured performance of SELECT queries.
Why use it?
It lets you inspect application records and investigate database problems without risking updates or deletions.

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/posthog/posthog-foss/querying-local-postgres
Any agent
npx skills add PostHog/posthog-foss --skill querying-local-postgres
Clone the repo
git clone --depth 1 https://github.com/PostHog/posthog-foss

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for querying-local-postgres

README.md
[![agentmods](https://agentmods.dev/badge/skills/posthog/posthog-foss/querying-local-postgres.svg)](https://agentmods.dev/skills/posthog/posthog-foss/querying-local-postgres)
Your own site
<a href="https://agentmods.dev/skills/posthog/posthog-foss/querying-local-postgres"><img src="https://agentmods.dev/badge/skills/posthog/posthog-foss/querying-local-postgres.svg" alt="Measured on agentmods" height="20"></a>
Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,560 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 $0.00079 $0.02560
Opus 5 $0.00039 $0.01280
Sonnet 5 $0.00016 $0.00512
Haiku 4.5 $0.00008 $0.00256

Measured 4d ago against content hash 17720bc9cb17, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

querying-local-postgres 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 4d 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/querying-local-postgres/SKILL.md · 167 lines

How it starts

The opening of the file, as written. The whole thing — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Querying local Postgres (READ-ONLY) — PostHog repo

User's query: $ARGUMENTS

Scope: This repo uses PostgreSQL for app metadata (teams, projects, flags, Django models, etc.). Analytics event data lives in ClickHouse, not Postgres — use HogQL / ClickHouse tools for events-style questions unless the user explicitly wants Postgres.

When to use

  • User asks to query the database, inspect tables, or run SQL against Postgres
  • Debugging: Row-level checks (e.g. why a team/project/flag row looks wrong), migrations, constraints, duplicate keys
  • Performance: EXPLAIN / EXPLAIN (ANALYZE, …) on read-only SELECT against Django or app tables

Instructions

  1. Strictly forbid mutations — See "Mutations strictly forbidden" below. If the user asks for any write or mutation, refuse and explain the skill is read-only.
  2. Translate the user's question into one or more read-only SQL statements.
  3. Show the SQL in a code block before running.
  4. Run using the command pattern below (always with PGOPTIONS='-c default_transaction_read_only=on' to force a read-only connection).
  5. Show results and give a brief interpretation (especially when used for debugging or plan review).

Mutations strictly forbidden

Do not run, suggest, or generate any of the following. Refuse and state that this skill is read-only.

  • DML: INSERT, UPDATE, DELETE, MERGE, TRUNCATE
  • DDL: CREATE, DROP, ALTER, RENAME
  • Other writes: COPY ... TO program, CALL (if it mutates), GRANT/REVOKE
  • EXPLAIN ANALYZE on anything other than a read-only SELECT (including WITH … SELECT). Do not wrap DML in EXPLAIN ANALYZE — it would execute the write. The read-only connection below rejects writes, but the agent must not attempt this pattern.
  • Any statement that modifies data, schema, or roles

Allowed:

  • SELECT (including WITH … SELECT)
  • EXPLAINSELECT (estimate-only plan; no execution)
  • EXPLAIN (ANALYZE, …) SELECTexecutes the SELECT once; use only for performance analysis. Must run on the read-only connection below.
  • SHOW, SELECT from catalog views (pg_stat_*, information_schema, etc.) when read-only

Read the full file on GitHub · 167 lines

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. 4d ago First seen · 167 lines · 79 tokens per session scan A 17720bc9cb17

Subscribe to this mod's changes

querying-local-postgres is a skill published in the GitHub repository PostHog/posthog-foss (713 stars, last pushed today), licensed MIT. It adds 79 tokens to every session and 2,560 once invoked, about $0.0004 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.

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