Use Circle Wallets

Choose and implement the right Circle wallet type for your application. Compares developer-controlled, user-controlled, and modular (passkey) wallets across...

Security Scan

The skill is mostly a documentation-only decision guide and doesn't ask for credentials or install code, but there are a few small incoherencies (external doc pointer and implicit dependency on other skills) that deserve vetting before use.

Purpose & Capability

The name/description match the SKILL.md content: it is a decision guide comparing Circle wallet types and directs the agent to trigger more specific wallet skills for implementation. No unusual binaries, env vars, or installs are requested, which is proportionate for a guidance skill.

Instruction Scope

The instructions stay within wallet-selection guidance, but they (a) instruct the agent to "TRIGGER" other skills by name (e.g., use-developer-controlled-wallets) which creates an implicit dependency on those skills and their privileges, and (b) include a prominent 'Always read this first' pointer to https://developers.circle.com/llms.txt (an unusual filename) — both warrant verification. The sheet contains strong prescriptive 'ALWAYS/NEVER' rules that could cause the agent to rigidly choose flows; this is stylistic but may lead to surprising behavior if the rest of the skill ecosystem isn't vetted.

Install Mechanism

Instruction-only skill with no install spec and no code files; nothing will be written to disk or executed by install, which is low risk.

Credentials

The skill requests no environment variables, credentials, or config paths — appropriate for a documentation/decision skill. However, because it instructs the agent to invoke other skills, check those skills for credential requests before granting them permission.

Persistence & Privilege

The skill is not flagged always:true and uses normal agent invocation. The main privilege-related concern is indirect: it tells the agent to invoke other wallet implementation skills — those downstream skills may require elevated credentials or persistent access, so vet them individually.

What to consider before installing

This is primarily a read-only decision guide and does not itself request credentials or install code, so the immediate risk is low. Before installing/using it: (1) verify the external links (especially https://developers.circle.com/llms.txt and the GitHub README) to ensure they point to legitimate Circle documentation; the llms.txt path looks unusual and should be checked. (2) Confirm that the referenced implementation skills (use-developer-controlled-wallets, use-user-controlled-wallets, use-modular-wallets) actually exist and review their env/credential requirements — those are the places where secrets or installs may be requested. (3) Be cautious about the 'ALWAYS/NEVER' rules: they are prescriptive and may force rigid action; understand whether they match your real-world constraints. If you want higher assurance, request the code or metadata for the downstream implementation skills before enabling agent invocation.

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.

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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.