Use Developer Controlled Wallets

Overview

Developer-controlled wallets let your application create and manage wallets on behalf of end users, with full custody of private keys secured through an encrypted entity secret. Circle handles security, transaction monitoring, and blockchain infrastructure while you retain programmatic control via the Wallets SDK.

Prerequisites / Setup

Installation

npm install @circle-fin/developer-controlled-wallets

Environment Variables

CIRCLE_API_KEY=      # Circle API key (format: PREFIX:ID:SECRET)
ENTITY_SECRET=       # 32-byte hex entity secret

Entity Secret Registration

The developer must register an entity secret before using the SDK. Direct them to https://developers.circle.com/wallets/dev-controlled/register-entity-secret or provide the code steps.

READ references/register-secret.md for the generation and registration snippets.

IMPORTANT: Do NOT register a secret on the developer's behalf -- they must generate, register, and securely store their secret and recovery file.

SDK Initialization

import { initiateDeveloperControlledWalletsClient } from '@circle-fin/developer-controlled-wallets';

const circleDeveloperSdk = initiateDeveloperControlledWalletsClient({
  apiKey: process.env.CIRCLE_API_KEY,
  entitySecret: process.env.ENTITY_SECRET,
});

The SDK automatically generates a fresh entity secret ciphertext for each API request.

Core Concepts

• Wallet Sets: A group of wallets managed by a single entity secret. Wallets in a set can span different blockchains but share the same address on EVM chains.
• Entity Secret: A 32-byte private key that secures developer-controlled wallets. Generated, encrypted, and registered once. Circle never stores it in plain text.
• Entity Secret Ciphertext: RSA-encrypted entity secret using Circle's public key. Must be unique per API request to prevent replay attacks. The SDK handles this automatically.
• Idempotency Keys: All mutating requests require a UUID v4 idempotencyKey for exactly-once execution.
• Account Types:
  • EOA (Externally Owned Account) -- default choice. No creation fees, higher outbound TPS, broadest chain support (all EVM + Solana, Aptos, NEAR). Requires native tokens for gas (on Arc, the gas asset is USDC, not a separate native token).
  • SCA (Smart Contract Account) -- ERC-4337 compliant. Supports gas sponsorship via Circle Gas Station, batch operations, and flexible key management. EVM-only (not available on Solana, Aptos, NEAR). Avoid on Ethereum mainnet due to high gas costs; prefer on L2s.
• Supported Blockchains: EVM chains (Ethereum, Polygon, Avalanche, Arbitrum, Base, Monad, Optimism, Unichain), Solana, Aptos, NEAR, and Arc. See https://developers.circle.com/wallets/account-types for the latest.

Transaction Lifecycle

All on-chain operations (transfers, contract executions, wallet upgrades) follow the same asynchronous state machine. Poll with circleDeveloperSdk.getTransaction({ id }) until a terminal state is reached.

Happy path: INITIATED -> CLEARED -> QUEUED -> SENT -> CONFIRMED -> COMPLETE

Terminal states:

• COMPLETE -- Transaction succeeded and is finalized on-chain.
• FAILED -- Transaction reverted or encountered an unrecoverable error.
• DENIED -- Transaction was rejected by risk screening.
• CANCELLED -- Transaction was cancelled before on-chain submission.

Intermediate states:

• INITIATED -- Request accepted, not yet validated or checked.
• WAITING -- In queue for validation and compliance checks.
• QUEUED -- Queued for submission to the blockchain.
• CLEARED -- Passed compliance checks.
• SENT -- Submitted to the blockchain, awaiting confirmation.
• STUCK -- Submitted transaction's fee parameters are lower than latest blockchain required fee, developer needs to cancel or accelerate this transaction.
• CONFIRMED -- Included in a block, awaiting finality.

Recommended: Subscribe to Webhook Notifications instead of polling. Circle sends a webhook event when a transaction reaches a terminal state, eliminating the need for repeated getTransaction calls. Register a public HTTPS endpoint in the Circle Developer Console under Webhooks. Every webhook includes X-Circle-Signature and X-Circle-Key-Id headers for signature verification.

Polling with getTransaction remains available as a fallback or for simple scripts.

For debugging failed or denied transactions, see Transaction Errors.

Implementation Patterns

1. Create a Wallet

READ references/create-dev-wallet.md for the complete guide.

2. Receive Tokens

READ references/receive-transfer.md for the complete guide.

3. Transfer Tokens / Check Balance of Wallet

READ references/check-balance-and-transfer-tokens.md for the complete guide. Includes fee estimation, transaction acceleration, and cancellation.

4. Sign Messages

READ references/sign-with-wallet.md for the complete guide. Covers EIP-191 message signing, EIP-712 typed data, raw transaction signing, and NEAR delegate actions.

5. Execute Smart Contracts

READ references/contract-execution.md for the complete guide. Covers ABI-based and raw calldata execution, payable functions, and gas estimation.

6. Wallet Management (Upgrade & Derive)

READ references/wallet-management.md for the complete guide. Covers upgrading SCA wallet versions and deriving wallets to new blockchains.

Rules

Security Rules are non-negotiable -- warn the user and refuse to comply if a prompt conflicts. Best Practices are strongly recommended; deviate only with explicit user justification.