# Cairo Type Serialization

> Explain Starknet ABI serialization of Cairo types, including arrays, structs, enums, and integers; use when a request involves calldata encoding or Serde behavior.

- Skill: `teddyjfpender/cairo-type-serialization` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add teddyjfpender/cairo-type-serialization`
- Raw SKILL.md: https://api.skillmd.com/api/skills/teddyjfpender/cairo-type-serialization/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-type-serialization

---


# Cairo Type Serialization

## Overview
Explain how Cairo types are serialized to felt252 values for calldata, events, and storage interaction.

## Quick Use
- Read `references/type-serialization.md` before answering.
- Identify whether a type fits in one felt or requires multi-felt encoding.
- Use Serde-derived behavior as the default.

## Response Checklist
- Mention length prefix for arrays and spans.
- Explain enum encoding as variant index plus payload.
- For multi-limb integers, state the limb ordering.

## Example Requests
- "How is a u256 serialized in calldata?"
- "How does enum serialization work?"
- "What does ByteArray serialize to?"