/use-circle-wallets

name: use-circle-wallets
description: "Choose and implement the right Circle wallet type for your application. Compares developer-controlled, user-controlled, and modular (passkey) wallets across custody model, key management, account types, blockchain support, and use cases. Use whenever blockchain wallet integrations are required for onchain application development. Triggers on: which wallet, choose wallet, wallet comparison, EOA vs SCA vs Modular Wallet, custody model, programmable wallets."
requirements:
  runtimes: []
  connectors: []

Overview

Circle offers three wallet types -- developer-controlled, user-controlled, and modular -- each with different custody models, account types, key management, and capabilities. This skill helps you pick the right one.

Quick Comparison

| | Developer-Controlled | User-Controlled | Modular (Passkey) | | --- | --- | --- | --- | | **Custody** | Developer | User | User | | **Auth** | API key + entity secret (backend) | Social login / email OTP / PIN | Passkey (WebAuthn) | | **Account types** | EOA, SCA | EOA, SCA | Modular Wallet SCA (ERC-6900) | | **Gas sponsorship** | SCA via Circle Paymaster | SCA via Circle Paymaster | Circle Paymaster or third-party paymaster | | **Custom modules** | No | No | Yes | | **Architecture** | Backend SDK only | Backend + frontend SDKs | Frontend SDK only |

Decision Guide

For the latest supported account types on different blockchains: https://developers.circle.com/wallets/account-types

For the latest supported features on different blockchains: https://developers.circle.com/wallets/supported-blockchains

1. **Who controls the keys / who is the custodian?**

• Developer controls -> Developer-controlled wallets -> step 3
• End user controls -> step 2

2. **Auth method?**

• Passkey (WebAuthn biometric) with extensible modules -> Modular wallets -> step 4
• Social login, email OTP, or PIN -> User-controlled wallets -> step 3

3. **Account type?**

• Solana, Aptos, or NEAR -> EOA (only option)
• Ethereum mainnet -> EOA (SCA gas costs prohibitive, Modular Wallet not supported)
• L2 (Arbitrum, Base, Polygon, Optimism, etc.) -> EOA if max TPS needed; SCA if gas sponsorship or batching needed; Modular Wallet if passkey or other modular plugins needed

4. **Chain check (Modular wallets)**

• Supported: Arbitrum, Avalanche, Base, Monad, Optimism, Polygon, Unichain
• NOT supported: Ethereum, Solana, Aptos, NEAR. Fall back to user-controlled wallets with SCA.

Example scenarios

READ `references/example-scenarios.md` for common scenarios mapped to a wallet-type decision and the skill to implement it.

Implementation Patterns

Once a wallet type has been determined, TRIGGER the corresponding skill:

• Developer-controlled -> `use-developer-controlled-wallets` skill
• User-controlled -> `use-user-controlled-wallets` skill
• Modular (Passkey) -> `use-modular-wallets` skill

Strict Rules

• ALWAYS select the wallet type before starting implementation using the comparison table and decision guide above.
• ALWAYS use EOA on Ethereum mainnet (SCA gas prohibitive, Modular Wallet not supported) and on Solana, Aptos, NEAR (SCA/Modular Wallet not available).
• ALWAYS prefer SCA or Modular Wallet on L2 chains (Arbitrum, Base, Polygon, Optimism, etc.) when gas sponsorship or batch operations are needed.
• NEVER mix wallet types in a single user flow -- pick one and use its corresponding skill.
• ALWAYS delegate to the specific wallet skill (`use-developer-controlled-wallets`, `use-user-controlled-wallets`, or `use-modular-wallets`) for implementation.

Safety & Escalation

This skill only **recommends** a wallet type; it performs no on-chain writes, transfers, signing, or key operations itself. Every side effect — creating a wallet, signing, sending funds, deploying a contract — happens in the delegated implementation skill, which owns confirmation for those actions.

Escalate before delegating when:

• **Missing context** — the custody model, target chain, or auth method is unclear. Ask the user; do not guess a wallet type.
• **Missing access** — the user lacks a Circle account, an API key + entity secret (developer-controlled), or a configured passkey domain (modular). Direct them to set that up first.
• **Unsafe effects** — the selected path will move real funds on mainnet. Flag that the implementation skill must obtain explicit user confirmation before any mainnet transaction.
• **User approval** — confirm the chosen wallet type with the user before handing off to the implementation skill.

Reference Links

• [Account Types](https://developers.circle.com/wallets/account-types)
• [Choosing Your Wallet Type](https://developers.circle.com/wallets/infrastructure-models)
• [Key Management](https://developers.circle.com/wallets/key-management)
• [Circle Developer Docs](https://developers.circle.com/llms.txt) -- **Always read this first** when looking for relevant documentation from the source website.

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DISCLAIMER: This skill is provided "as is" without warranties, is subject to the [Circle Developer Terms](https://console.circle.com/legal/developer-terms), and output generated may contain errors and/or include fee configuration options (including fees directed to Circle); additional details are in the repository [README](https://github.com/circlefin/skills/blob/master/README.md).