Configuration

Options to configure a bundler with env variables.

The Bundler can be configured through environment variables or a .env file at the working directory. Some variables are required while others are optional.

Environment variables

Required

# Connection string to a standard Ethereum node.
ERC4337_BUNDLER_ETH_CLIENT_URL

# The private key for the EOA used to relay bundles to the EntryPoint.
ERC4337_BUNDLER_PRIVATE_KEY

Optional

# Port to run the Client on.
# Defaults to 4337.
ERC4337_BUNDLER_PORT

# Data directory to store embedded mempool.
# Defaults to /tmp/stackup_bundler.
ERC4337_BUNDLER_DATA_DIRECTORY

# Comma separated EntryPoint addresses to support.
# The first address is the preferred EntryPoint.
# Default depends on major version, see release notes on GitHub.
ERC4337_BUNDLER_SUPPORTED_ENTRY_POINTS

# Address to send gas refunds for relaying bundlers.
# Defaults to the public address of the private key.
ERC4337_BUNDLER_BENEFICIARY

# The maximum verificationGasLimit on a received UserOperation.
# Defaults to 1500000 wei.
ERC4337_BUNDLER_MAX_VERIFICATION_GAS

# The maximum number of pending UserOperations an unstaked sender is allowed.
# Defaults to 4.
ERC4337_BUNDLER_MAX_OPS_FOR_UNSTAKED_SENDER

Private mode variables

These variables are relevant to bundlers running in private mode.

Optional

# The limit for how many ops can be seen from a client without being included on-chain.
# Defaults to 3.
ERC4337_BUNDLER_RELAYER_BANNED_THRESHOLD

# The limit for how long a banned client will be rejected for in seconds.
# Defaults to 86400 seconds (i.e. 24 hours).
ERC4337_BUNDLER_RELAYER_BANNED_TIME_WINDOW

Searcher mode variables

These variables are relevant to bundlers running in searcher mode.

Required

# Connection string to a block builder that supports eth_sendBundle RPC.
ERC4337_BUNDLER_ETH_BUILDER_URL

Optional

# The number of future blocks to submit a transaction for.
# A higher value may slow down processing but has a higher chance of inclusion.
# Defaults to 25.
ERC4337_BUNDLER_BLOCKS_IN_THE_FUTURE