# Deep Reference

> Answers questions about the billing schema. Use when a question names a billing table, or when the user asks how invoices relate to subscriptions.

- Skill: `letsloose501/deep-reference` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add letsloose501/deep-reference`
- Raw SKILL.md: https://api.skillmd.com/api/skills/letsloose501/deep-reference/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: letsloose501 (https://skillmd.com/u/letsloose501)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/letsloose501/deep-reference

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# Deep reference

1. Find the table in [the schema notes](references/billing/tables/invoices.md).
2. Answer from that file only. Stop when the answer names a column.

## When to open which reference

[invoices.md](references/billing/tables/invoices.md) holds the column list.