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 Entity secret (backend) Social login / email OTP / PIN Passkey (WebAuthn)

Account types EOA, SCA EOA, SCA MSCA only

Gas sponsorship SCA via Gas Station SCA via Gas Station Gas Station 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 blockchains: https://developers.circle.com/wallets/account-types

Step 1 -- Who controls the keys?

• Developer controls (no user approval) -> Developer-controlled wallets -> Step 3

• End user controls -> Step 2

Step 2 -- Auth method?

• Passkey (WebAuthn biometric) with extensible modules -> Modular wallets -> Step 4

• Social login, email OTP, or PIN -> User-controlled wallets -> Step 3

Step 3 -- Account type?

• Solana, Aptos, or NEAR -> EOA (only option)

• Ethereum mainnet -> EOA (SCA gas costs prohibitive, MSCA not supported)

• L2 (Arbitrum, Base, Polygon, Optimism, etc.) -> SCA if gas sponsorship or batching needed; EOA if max TPS needed

Step 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

Scenario Decision Skill

Payment backend, programmatic payouts, high TPS Developer-controlled + EOA use-developer-controlled-wallets

Consumer app with Google/Apple login, gasless UX User-controlled + SCA on L2 use-user-controlled-wallets

DeFi app with biometric auth, custom modules Modular on L2 use-modular-wallets

NFT marketplace on Ethereum L1 User-controlled + EOA use-user-controlled-wallets

AI agent, autonomous multi-chain transactions Developer-controlled + EOA use-developer-controlled-wallets

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, MSCA not supported) and on Solana, Aptos, NEAR (SCA/MSCA not available).

• ALWAYS prefer SCA or MSCA 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.

Reference Links

• Account Types

• Choosing Your Wallet Type

• Key Management

• Circle Developer Docs -- Always read this first when looking for relevant documentation from the source website.

DISCLAIMER: This skill is provided "as is" without warranties, is subject to the Circle 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.