Release Notes - Developer Services - 2025

Launched the Bridge Kit SDK.

Created the following new topics to support Bridge Kit:

• Bridge Kit Overview
• Adapter Setups
• Quickstart: Transfer USDC from Base to Ethereum
• Quickstart: Transfer USDC from Ethereum to Solana
• Bridge Kit Installation
• Collect a Transfer Fee
• Configure Transfer Speed and Maximum Cost
• Estimate Costs Before Transferring
• Specify Recipient Address
• Bridge Kit SDK Reference
• Event Handling
• Error Recovery and Troubleshooting

Expanded Gateway support to include HyperEVM, Sei, Sonic, and World Chain.

Updated the following documentation to reflect Gateway support for HyperEVM, Sei, Sonic, and World Chain:

• Gateway Fees
• Gateway Smart Contract Addresses
• Gateway Supported Blockchains

Updated the following Gateway endpoints:

• Added expirationBlock to the POST /v1/transfer response
• Added processedHeight and burnIntentExpirationHeight to the GET /v1/info response

Replaced the transaction state PENDING_RISK_SCREENING with CLEARED

Added networkFeeRaw to the response of the following endpoints:

• POST /transactions/contractExecution/estimateFee
• POST /transactions/transfer/estimateFee
• POST /contracts/deploy/estimateFee

Expanded Developer Services support for Avalanche Mainnet and Avalanche Fuji Testnet to include smart contract accounts (SCAs), modular wallets, and Gas Station sponsorship.

Updated the following documentation to reflect Avalanche support:

• Account Types
• Blockchain Compatibility for Developer Services APIs
• Blockchain Confirmations
• Blockchain Infrastructure
• Gas Fees
• Gas Station
• Gas Station Contract Addresses
• Gas Station Policy Management
• Modular Wallets Quickstart
• Modular Wallets Web SDK
• Modular Wallets iOS SDK
• Modular Wallets Android SDK
• Send a Gasless Transaction
• Supported Blockchains and Currencies

Added enum values AVAX, AVAX-FUJI to the blockchain request field for the following Circle Contracts APIs:

• POST /contracts/deploy
• POST /contracts/deploy/estimateFee
• POST /contracts/import
• POST /contracts/query
• POST /templates/{id}/deploy
• POST /templates/{id}/deploy/estimateFee

Launched Circle Gateway on testnet.

Created the following new topics to support Circle Gateway:

• Gateway Overview
• Gateway Technical Guide
• Quickstart: Create and Transfer a Unified USDC Balance
• Gateway Supported Blockchains
• Gateway Contract Addresses
• Gateway Contract Interfaces and Events
• Gateway Fees

Added the following endpoints to support Circle Gateway:

• POST /v1/balances
• GET /v1/info
• POST /v1/transfer

Added an optional delayReason field to CCTP transfer status responses to provide context for delayed transfers.

The delayReason field is now returned in the following CCTP Iris endpoints:

• GET /v2/messages - Get messages and attestations

Added support for the order request parameter (ASC or DESC) to enable sorting by createDate for improved client-side data handling.

The order parameter is now supported in the following endpoints:

• GET /v1/w3s/walletSets - Get all wallet sets (developer-controlled)
• GET /v1/w3s/transactions - List transactions (user/developer-controlled)
• GET /v1/w3s/wallets - List wallets (user/developer-controlled)
• GET /v1/w3s/users - List users (user-controlled)

Launched Developer Services support for Aptos Mainnet and Testnet.

Updated the following documentation to reflect Aptos support:

• Account Types
• Blockchain Infrastructure
• Blockchain Compatibility for Developer Services APIs
• Blockchain Confirmations
• Gas Fees
• Gas Station
• Gas Station Contract Addresses
• Gas Station Policy Management
• Supported Blockchains and Currencies
• Testnet Faucets
• Receive an Inbound Transfer (User-Controlled Wallets)
• Receive an Inbound Transfer (Developer-Controlled Wallets)
• Send a Gasless Transaction

Added enum values APTOS, APTOS-TESTNET to the blockchain request field for the following APIs:

• POST /developer/wallets
• POST /user/wallets
• GET /wallets
• GET /transactions
• POST /transactions/transfer
• POST /transactions/transfer/estimateFee
• POST /transactions/validateAddress
• POST /user/initialize

Added programmatic gas price optimization to modular wallets web SDK.

Updated the following documentation to reflect programmatic gas price optimization support in modular wallets web SDK:

• Modular Wallets Web SDK:
  • Added GetUserOperationGasPriceReturnType interface.
  • Added GetUserOperationGasPriceRpcSchema type.
  • Added getUserOperationGasPrice function.

Removed Compliance Engine's Travel Rule from the developer documentation as it's been deprecated.

Added support for Avalanche and Unichain to Paymaster v0.8.

Updated the following documentation to reflect Avalanche and Unichain support in Paymaster v0.8:

• Paymaster Overview
• Paymaster Addresses and Events

Added Paymaster v0.8 documentation.

Updated the following pages to reflect support for EntryPoint v0.8 of the ERC-4337 contract in Paymaster:

• Paymaster Overview
• Quickstart: Build a Wallet to Pay Gas Fees with USDC
• Paymaster Addresses and Events

Added passkey recovery support to modular wallets web SDK.

Added the following documentation to support passkey recovery using the modular wallets web SDK:

• How To Set Up Passkey Recovery.

Updated the following documentation to support passkey recovery in modular wallets:

• Modular Wallets Web SDK:
  • Added estimateExecuteRecoveryGas function.
  • Added estimateRegisterRecoveryAddressGas function.
  • Added executeRecovery function.
  • Added recoveryActions function.
  • Added registerRecoveryAddress function.
• Modular Wallets Passkey

Updated the following documentation to reflect the removed API and the new Derive a Wallet API endpoint:

• Programmable Wallet API Rate Limits

• Removed API for products that never officially launched. The following APIs were removed:

  • Backfill a Wallet API: PUT /developer/wallets/:id/backfill

• Added content schema, description, and the X-Request-Id header to the 201 response for the following APIs:

  • POST /v1/w3s/user/initialize
  • POST /v1/w3s/user/pin
  • PUT /v1/w3s/user/pin
  • POST /v1/w3s/user/pin/restore
  • POST /v1/w3s/user/wallets
  • POST /v1/w3s/user/transactions/{id}/accelerate
  • POST /v1/w3s/user/transactions/{id}/cancel
  • POST /v1/w3s/user/transactions/walletUpgrade

• Added the new Derive a Wallet API: PUT /developer/wallets/:id/blockchains/:blockchain

• Launched Developer Services, including Circle Contracts, on Optimism (OP) and Base (BASE) blockchains.
• Added modular wallets and Circle Contracts support on Unichain (UNI) blockchain.
• Added a new tutorial in modular wallets to showcase how to add Externally Owned Account (EOA) signers for Circle Smart Accounts.

Added the following documents:

• Dynamic Integration Tutorial

Added Optimism (OP) and Base (BASE) blockchains to tables of support:

• Account Types
• Blockchain Compatibility for Developer Services APIs
• Blockchain Confirmations
• Gas Fees
• Gas Station
• Gas Station Contract Addresses
• Gas Station Policy Management
• Modular Wallets Android SDK
• Modular Wallets iOS SDK
• Modular Wallets Quickstart
• Receive an Inbound Transfer (User-Controlled Wallets)
• Receive an Inbound Transfer (Developer-Controlled Wallets)
• Send a Gasless Transaction
• Supported Blockchains and Currencies
• Testnet Faucets

• Added enum values BASE, BASE-SEPOLIA, OP, OP-SEPOLIA to the blockchain request field for the following APIs:

  • POST /developer/wallets
  • POST /user/wallets
  • GET /wallets
  • GET /transactions
  • POST /transactions/contractExecution/estimateFee
  • POST /transactions/transfer
  • POST /transactions/transfer/estimateFee
  • POST /transactions/validateAddress
  • POST /user/initialize
  • GET /config/entity/monitoredTokens
  • GET /contracts
  • POST /contracts/deploy
  • POST /contracts/deploy/estimateFee
  • POST /contracts/import
  • POST /contracts/query
  • POST /templates/{id}/deploy
  • POST /templates/{id}/deploy/estimateFee
  • GET /contracts/monitors
  • POST /contracts/monitors
  • GET /contracts/events

• Added enum values UNI and UNI-SEPOLIA to the blockchain request field for the following APIs:

  • GET /contracts
  • POST /contracts/deploy
  • POST /contracts/deploy/estimateFee
  • POST /contracts/import
  • POST /contracts/query
  • POST /templates/{id}/deploy
  • POST /templates/{id}/deploy/estimateFee
  • GET /contracts/monitors
  • POST /contracts/monitors
  • GET /contracts/events

Launched the SDK Explorer for Developer Services server-side SDKs.

Added the following pages for the SDK Explorer:

• SDK Explorer Overview
• Getting Started with Developer-Controlled Wallets - Node.js
• Getting Started with Developer-Controlled Wallets - Python
• Getting Started with User-Controlled Wallets - Node.js
• Getting Started with User-Controlled Wallets - Python
• Getting Started with Contracts - Node.js
• Getting Started with Contracts - Python

The following Circle Product Lines have been renamed:

The following Circle Products have been renamed:

These name changes are part of a broader effort to simplify and align our product naming, creating a more unified developer experience across the Circle platform.

Updated the following document to reflect the new Backfill a wallet API endpoint:

• Programmable Wallet API Rate Limits

Added new API endpoints:

• GET /v1/w3s/developer/wallets/balances
• PUT /v1/w3s/developer/wallets/{id}/backfill

Removed USDC Access from the developer documentation as it's no longer available for new users.

• Updated description for the following APIs:

  • POST /developer/sign/message
  • POST /developer/sign/typeData
  • POST /user/sign/message
  • POST /user/sign/typeData

• Added example for Address and ContractAddress

• Updated abiFunctionSignature to be optional for the POST /transactions/contractExecution/estimateFee API.

• Added enum values UNI and UNI-SEPOLIA to the chain request field for the following API:

  • POST /compliance/screening/addresses

Added EIP-1193 example for modular wallets

Added a code example for EIP-1193:

• Key Features

Launched Web3 Services on Unichain mainnet

Added Unichain mainnets to tables of support:

• Supported Blockchains and Currencies
• Blockchain Compatibility for Web3 Services APIs
• Blockchain Confirmations
• Gas Fees
• Gas Station Contract Addresses
• Gas Station

Added information on batching user-ops with the Circle API.

Updated information on batch operations:

• Account Types
• Batch Operations

• Added enum value UNI to the blockchain request field for the following APIs:

  • POST /developer/wallets
  • POST /user/wallets
  • GET /wallets
  • GET /transactions
  • POST /transactions/validateAddress
  • POST /user/initialize
  • GET /config/entity/monitoredTokens
  • POST /developer/transactions/transfer
  • POST /transactions/transfer/estimateFee
  • POST /user/transactions/transfer
  • POST /user/transactions/transfer/estimateFee

Launched user-controlled wallets signing on EVM chains.

Added information for signing transactions with user-controlled wallets:

• Confirmation UIs
• Signing APIs
• Supported Blockchains and Currencies

• Updated the description of error code 155236: The provided fee in request is invalid.

Launched modular wallets.

Added modular wallets content to the Wallets section of the Developer Services pillar:

• Modular Wallets Quickstart
• Modular Wallets SDKs
• Modular Wallets Sample App

Added modular wallets endpoints:

• GET buidl/transfers
• GET buidl/userOps
• GET buidl/wallets/balances
• GET buidl/wallets/nfts

Launched Web3 Services on Unichain testnet.

Added Unichain testnet to tables of support:

• Supported Blockchains and Currencies
• Blockchain Compatibility for Web3 Services APIs
• Blockchain Confirmations
• Gas Fees
• Gas Station Contract Addresses
• Gas Station