# Cairo Contract Storage

> Explain Starknet contract storage layout, the storage struct, Store trait, and read/write access; use when a request involves storage variables or storage layout in Cairo.

- Skill: `teddyjfpender/cairo-contract-storage` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add teddyjfpender/cairo-contract-storage`
- Raw SKILL.md: https://api.skillmd.com/api/skills/teddyjfpender/cairo-contract-storage/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: teddyjfpender (https://skillmd.com/u/teddyjfpender)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/teddyjfpender/cairo-contract-storage

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# Cairo Contract Storage

## Overview
Explain how contract storage is declared and accessed, and how storage keys are computed.

## Quick Use
- Read `references/contract-storage.md` before answering.
- Use `#[storage]` struct for storage fields.
- Use `.read()` and `.write()` on storage variables in `ContractState`.

## Response Checklist
- Ensure storage field types implement `starknet::Store` (derive it when possible).
- Mention storage keys are derived from the variable name and hashed.
- Use `self` or `ref self` correctly depending on mutability.

## Example Requests
- "How do I declare storage in a Cairo contract?"
- "Why does my storage field need Store?"
- "How is the storage key computed for a variable?"