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Precompiles reference

ArbOS provides L2-specific precompiles with methods smart contracts can call the same way they can solidity functions. This reference page exhaustively documents the specific calls ArbOS makes available through precompiles. For a more conceptual description of what precompiles are and how they work, please refer to the precompiles conceptual page.

This reference page is divided into two sections. The first one lists all precompiles in a summary table with links to the reference of the specific precompile, along with the address where they live, their purpose and links to the go implementation and solidity interface. The second one details the methods available in each precompile with links to the specific implementation.

General information of precompiles

This section is divided into two tables. We first list precompiles we expect users to most often use, and then the rest of precompiles. However, both tables display the same information: name and purpose of the precompile, address, and links to the solidity interface and the go implementation.

Common precompiles

PrecompileAddressSolidity interfaceGo implementationPurpose
ArbAggregator0x6dInterfaceImplementationConfiguring transaction aggregation
ArbGasInfo0x6cInterfaceImplementationInfo about gas pricing
ArbRetryableTx0x6eInterfaceImplementationManaging retryables
ArbSys0x64InterfaceImplementationSystem-level functionality
ArbWasm0x71InterfaceImplementationManages Stylus contracts
ArbWasmCache0x72InterfaceImplementationManages Stylus cache

Other precompiles

PrecompileAddressSolidity interfaceGo implementationPurpose
ArbAddressTable0x66InterfaceImplementationSupporting compression of addresses
ArbBLS---Disabled (Former registry of BLS public keys)
ArbDebug0xffInterfaceImplementationTesting tools
ArbFunctionTable0x68InterfaceImplementationNo longer used
ArbInfo0x65InterfaceImplementationInfo about accounts
ArbOwner0x70InterfaceImplementationChain administration, callable only by chain owner
ArbOwnerPublic0x6bInterfaceImplementationInfo about chain owners
ArbosTest0x69InterfaceImplementationNo longer used
ArbStatistics0x6fInterfaceImplementationInfo about the pre-Nitro state

Precompiles reference

ArbAddressTable

ArbAddressTable (Interface | Implementation) provides the ability to create short-hands for commonly used accounts.

Precompile address: 0x0000000000000000000000000000000000000066

MethodSolidity interfaceGo implementationDescription
addressExists(address addr)

Interface

Implementation

AddressExists checks if an address exists in the table
compress(address addr)

Interface

Implementation

Compress and returns the bytes that represent the address
decompress(bytes calldata buf, uint256 offset)

Interface

Implementation

Decompress the compressed bytes at the given offset with those of the corresponding account

lookup(address addr)

Interface

Implementation

Lookup the index of an address in the table
lookupIndex(uint256 index)

Interface

Implementation

LookupIndex for an address in the table by index
register(address addr)

Interface

Implementation

Register adds an account to the table, shrinking its compressed representation
size()

Interface

Implementation

Size gets the number of addresses in the table

ArbAggregator

ArbAggregator (Interface | Implementation) provides aggregators and their users methods for configuring how they participate in L1 aggregation. Arbitrum One's default aggregator is the Sequencer, which a user will prefer unless SetPreferredAggregator is invoked to change it.

Compression ratios are measured in basis points. Methods that are checkmarked are access-controlled and will revert if not called by the aggregator, its fee collector, or a chain owner.

Precompile address: 0x000000000000000000000000000000000000006D

MethodSolidity interfaceGo implementationDescription

⚠️getPreferredAggregator(address addr)

Interface

Implementation

Deprecated: Do not use this method.

⚠️getDefaultAggregator()

Interface

Implementation

Deprecated: Do not use this method.
getBatchPosters()

Interface

Implementation

GetBatchPosters gets the addresses of all current batch posters
addBatchPoster(address newBatchPoster)

Interface

Implementation

Adds newBatchPoster as a batch poster
getFeeCollector(address batchPoster)

Interface

Implementation

GetFeeCollector gets a batch poster's fee collector
setFeeCollector(address batchPoster, address newFeeCollector)

Interface

Implementation

SetFeeCollector sets a batch poster's fee collector (caller must be the batch poster, its fee collector, or an owner)

⚠️getTxBaseFee(address aggregator)

Interface

Implementation

Deprecated: returns 0

⚠️setTxBaseFee(address aggregator, uint256 feeInL1Gas)

Interface

Implementation

Deprecated: does nothing

Note: methods marked with ⚠️ are deprecated and their use is not supported.

ArbBLS

Disabled

This precompile has been disabled. It previously provided a registry of BLS public keys for accounts.

ArbDebug

ArbDebug (Interface | Implementation) provides mechanisms useful for testing. The methods of ArbDebug are only available for chains with the AllowDebugPrecompiles chain parameter set. Otherwise, calls to this precompile will revert.

Precompile address: 0x00000000000000000000000000000000000000ff

MethodSolidity interfaceGo implementationDescription
becomeChainOwner()

Interface

Implementation

Caller becomes a chain owner
events(bool flag, bytes32 value)

Interface

Implementation

Emit events with values based on the args provided
eventsView()

Interface

Implementation

Tries (and fails) to emit logs in a view context
customRevert(uint64 number)

Interface

Implementation

Throws a custom error
panic()

Interface

Implementation

Halts the chain by panicking in the STF
legacyError()

Interface

Implementation

Throws a hardcoded error
EventSolidity interfaceGo implementationDescription
Basic

Interface

Implementation

Emitted in Events for testing

Mixed

Interface

Implementation

Emitted in Events for testing

Store

Interface

Implementation

Never emitted (used for testing log sizes)

ArbFunctionTable

ArbFunctionTable (Interface | Implementation) provides aggregators the ability to manage function tables, to enable one form of transaction compression. The Nitro aggregator implementation does not use these, so these methods have been stubbed and their effects disabled. They are kept for backwards compatibility.

Precompile address: 0x0000000000000000000000000000000000000068

MethodSolidity interfaceGo implementationDescription
upload(bytes calldata buf)

Interface

Implementation

Upload does nothing
size(address addr)

Interface

Implementation

Size returns the empty table's size, which is 0
get(address addr, uint256 index)

Interface

Implementation

Get reverts since the table is empty

ArbGasInfo

ArbGasInfo (Interface | Implementation) provides insight into the cost of using the chain. These methods have been adjusted to account for Nitro's heavy use of calldata compression. Of note to end-users, we no longer make a distinction between non-zero and zero-valued calldata bytes.

Precompile address: 0x000000000000000000000000000000000000006C

MethodSolidity interfaceGo implementationDescription
getPricesInWeiWithAggregator(address aggregator)

Interface

Implementation

GetPricesInWeiWithAggregator gets prices in wei when using the provided aggregator
getPricesInWei()

Interface

Implementation

GetPricesInWei gets prices in wei when using the caller's preferred aggregator
getPricesInArbGasWithAggregator(address aggregator)

Interface

Implementation

GetPricesInArbGasWithAggregator gets prices in ArbGas when using the provided aggregator

getPricesInArbGas()

Interface

Implementation

GetPricesInArbGas gets prices in ArbGas when using the caller's preferred aggregator
getGasAccountingParams()

Interface

Implementation

GetGasAccountingParams gets the rollup's speed limit, pool size, and tx gas limit
getMinimumGasPrice()

Interface

Implementation

GetMinimumGasPrice gets the minimum gas price needed for a transaction to succeed
getL1BaseFeeEstimate()

Interface

Implementation

GetL1BaseFeeEstimate gets the current estimate of the L1 basefee
getL1BaseFeeEstimateInertia()

Interface

Implementation

GetL1BaseFeeEstimateInertia gets how slowly ArbOS updates its estimate of the L1 basefee

getL1RewardRate()

Interface

Implementation

GetL1RewardRate gets the L1 pricer reward rate
getL1RewardRecipient()

Interface

Implementation

GetL1RewardRecipient gets the L1 pricer reward recipient
getL1GasPriceEstimate()

Interface

Implementation

GetL1GasPriceEstimate gets the current estimate of the L1 basefee
getCurrentTxL1GasFees()

Interface

Implementation

GetCurrentTxL1GasFees gets the fee paid to the aggregator for posting this tx
getGasBacklog()

Interface

Implementation

GetGasBacklog gets the backlogged amount of gas burnt in excess of the speed limit
getPricingInertia()

Interface

Implementation

Returns how slowly ArbOS updates the L2 basefee in response to backlogged gas
getGasBacklogTolerance()

Interface

Implementation

GetGasBacklogTolerance gets the forgivable amount of backlogged gas ArbOS will ignore when raising the basefee

getL1PricingSurplus()

Interface

Implementation

Returns the surplus of funds for L1 batch posting payments (may be negative)
getPerBatchGasCharge()

Interface

Implementation

Returns the base charge (in L1 gas) attributed to each data batch in the calldata pricer

getAmortizedCostCapBips()

Interface

Implementation

Returns the cost amortization cap in basis points
getL1FeesAvailable()

Interface

Implementation

Returns the available funds from L1 fees
getL1PricingEquilibrationUnits()

Interface

Implementation

Returns the equilibration units parameter for L1 price adjustment algorithm (Available since ArbOS 20)

getLastL1PricingUpdateTime()

Interface

Implementation

Returns the last time the L1 calldata pricer was updated (Available since ArbOS 20)
getL1PricingFundsDueForRewards()

Interface

Implementation

Returns the amount of L1 calldata payments due for rewards (per the L1 reward rate) (Available since ArbOS 20)

getL1PricingUnitsSinceUpdate()

Interface

Implementation

Returns the amount of L1 calldata posted since the last update (Available since ArbOS 20)

getLastL1PricingSurplus()

Interface

Implementation

Returns the L1 pricing surplus as of the last update (may be negative) (Available since ArbOS 20)

ArbInfo

ArbInfo (Interface | Implementation) provides the ability to lookup basic info about accounts and contracts.

Precompile address: 0x0000000000000000000000000000000000000065

MethodSolidity interfaceGo implementationDescription
getBalance(address account)

Interface

Implementation

GetBalance retrieves an account's balance
getCode(address account)

Interface

Implementation

GetCode retrieves a contract's deployed code

ArbosTest

ArbosTest (Interface | Implementation) provides a method of burning arbitrary amounts of gas, which exists for historical reasons. In Classic, ArbosTest had additional methods only the zero address could call. These have been removed since users don't use them and calls to missing methods revert.

Precompile address: 0x0000000000000000000000000000000000000069

MethodSolidity interfaceGo implementationDescription
burnArbGas(uint256 gasAmount)

Interface

Implementation

BurnArbGas unproductively burns the amount of L2 ArbGas

ArbOwner

ArbOwner (Interface | Implementation) provides owners with tools for managing the rollup. Calls by non-owners will always revert.

Most of Arbitrum Classic's owner methods have been removed since they no longer make sense in Nitro:

  • What were once chain parameters are now parts of ArbOS's state, and those that remain are set at genesis.
  • ArbOS upgrades happen with the rest of the system rather than being independent
  • Exemptions to address aliasing are no longer offered. Exemptions were intended to support backward compatibility for contracts deployed before aliasing was introduced, but no exemptions were ever requested.

Precompile address: 0x0000000000000000000000000000000000000070

MethodSolidity interfaceGo implementationDescription
addChainOwner(address newOwner)

Interface

Implementation

AddChainOwner adds account as a chain owner
removeChainOwner(address ownerToRemove)

Interface

Implementation

RemoveChainOwner removes account from the list of chain owners
isChainOwner(address addr)

Interface

Implementation

IsChainOwner checks if the account is a chain owner
getAllChainOwners()

Interface

Implementation

GetAllChainOwners retrieves the list of chain owners
setL1BaseFeeEstimateInertia(uint64 inertia)

Interface

Implementation

SetL1BaseFeeEstimateInertia sets how slowly ArbOS updates its estimate of the L1 basefee

setL2BaseFee(uint256 priceInWei)

Interface

Implementation

SetL2BaseFee sets the L2 gas price directly, bypassing the pool calculus
setMinimumL2BaseFee(uint256 priceInWei)

Interface

Implementation

SetMinimumL2BaseFee sets the minimum base fee needed for a transaction to succeed
setSpeedLimit(uint64 limit)

Interface

Implementation

SetSpeedLimit sets the computational speed limit for the chain
setMaxTxGasLimit(uint64 limit)

Interface

Implementation

SetMaxTxGasLimit sets the maximum size a tx (and block) can be
setL2GasPricingInertia(uint64 sec)

Interface

Implementation

SetL2GasPricingInertia sets the L2 gas pricing inertia
setL2GasBacklogTolerance(uint64 sec)

Interface

Implementation

SetL2GasBacklogTolerance sets the L2 gas backlog tolerance
getNetworkFeeAccount()

Interface

Implementation

GetNetworkFeeAccount gets the network fee collector
getInfraFeeAccount()

Interface

Implementation

GetInfraFeeAccount gets the infrastructure fee collector
setNetworkFeeAccount(address newNetworkFeeAccount)

Interface

Implementation

SetNetworkFeeAccount sets the network fee collector to the new network fee account
setInfraFeeAccount(address newInfraFeeAccount)

Interface

Implementation

SetInfraFeeAccount sets the infra fee collector to the new network fee account
scheduleArbOSUpgrade(uint64 newVersion, uint64 timestamp)

Interface

Implementation

ScheduleArbOSUpgrade to the requested version at the requested timestamp
setL1PricingEquilibrationUnits(uint256 equilibrationUnits)

Interface

Implementation

Sets equilibration units parameter for L1 price adjustment algorithm
setL1PricingInertia(uint64 inertia)

Interface

Implementation

Sets inertia parameter for L1 price adjustment algorithm
setL1PricingRewardRecipient(address recipient)

Interface

Implementation

Sets reward recipient address for L1 price adjustment algorithm
setL1PricingRewardRate(uint64 weiPerUnit)

Interface

Implementation

Sets reward amount for L1 price adjustment algorithm, in wei per unit
setL1PricePerUnit(uint256 pricePerUnit)

Interface

Implementation

Set how much ArbOS charges per L1 gas spent on transaction data.
setPerBatchGasCharge(int64 cost)

Interface

Implementation

Sets the base charge (in L1 gas) attributed to each data batch in the calldata pricer
setBrotliCompressionLevel(uint64 level)

Interface

Implementation

Sets the Brotli compression level used for fast compression (Available in ArbOS version 12 with default level as 1)

setAmortizedCostCapBips(uint64 cap)

Interface

Implementation

Sets the cost amortization cap in basis points
releaseL1PricerSurplusFunds(uint256 maxWeiToRelease)

Interface

Implementation

Releases surplus funds from L1PricerFundsPoolAddress for use
setInkPrice(uint32 price)

Interface

Implementation

Sets the amount of ink 1 gas buys
setWasmMaxStackDepth(uint32 depth)

Interface

Implementation

Sets the maximum depth (in wasm words) a wasm stack may grow
setWasmFreePages(uint16 pages)

Interface

Implementation

Gets the number of free wasm pages a tx gets
setWasmPageGas(uint16 gas)

Interface

Implementation

Sets the base cost of each additional wasm page
setWasmPageLimit(uint16 limit)

Interface

Implementation

Sets the initial number of pages a wasm may allocate
setWasmMinInitGas(uint8 gas, uint16 cached)

Interface

Implementation

Sets the minimum costs to invoke a program
setWasmInitCostScalar(uint64 percent)

Interface

Implementation

Sets the linear adjustment made to program init costs
setWasmExpiryDays(uint16 _days)

Interface

Implementation

Sets the number of days after which programs deactivate
setWasmKeepaliveDays(uint16 _days)

Interface

Implementation

Sets the age a program must be to perform a keepalive
setWasmBlockCacheSize(uint16 count)

Interface

Implementation

Sets the number of extra programs ArbOS caches during a given block
addWasmCacheManager(address manager)

Interface

Implementation

Adds account as a wasm cache manager
removeWasmCacheManager(address manager)

Interface

Implementation

Removes account from the list of wasm cache managers
setChainConfig(string calldata chainConfig)

Interface

Implementation

Sets serialized chain config in ArbOS state
EventSolidity interfaceGo implementationDescription
OwnerActs

Interface

Implementation

/ Emitted when a successful call is made to this precompile

ArbOwnerPublic

ArbOwnerPublic (Interface | Implementation) provides non-owners with info about the current chain owners.

Precompile address: 0x000000000000000000000000000000000000006b

MethodSolidity interfaceGo implementationDescription
isChainOwner(address addr)

Interface

Implementation

IsChainOwner checks if the user is a chain owner
rectifyChainOwner(address ownerToRectify)

Interface

Implementation

RectifyChainOwner checks if the account is a chain owner (Available in ArbOS version 11)

getAllChainOwners()

Interface

Implementation

GetAllChainOwners retrieves the list of chain owners
getNetworkFeeAccount()

Interface

Implementation

GetNetworkFeeAccount gets the network fee collector
getInfraFeeAccount()

Interface

Implementation

GetInfraFeeAccount gets the infrastructure fee collector
getBrotliCompressionLevel()

Interface

Implementation

GetBrotliCompressionLevel gets the current brotli compression level used for fast compression

getScheduledUpgrade()

Interface

Implementation

Returns (0, 0, nil) if no ArbOS upgrade is scheduled.
EventSolidity interfaceGo implementationDescription
ChainOwnerRectified

Interface

Implementation

Emitted when verifying a chain owner

ArbRetryableTx

ArbRetryableTx (Interface | Implementation) provides methods for managing retryables. The model has been adjusted for Nitro, most notably in terms of how retry transactions are scheduled. For more information on retryables, please see the retryable documentation.

Precompile address: 0x000000000000000000000000000000000000006E

MethodSolidity interfaceGo implementationDescription
redeem(bytes32 ticketId)

Interface

Implementation

Redeem schedules an attempt to redeem the retryable, donating all of the call's gas to the redeem attempt

getLifetime()

Interface

Implementation

GetLifetime gets the default lifetime period a retryable has at creation
getTimeout(bytes32 ticketId)

Interface

Implementation

GetTimeout gets the timestamp for when ticket will expire
keepalive(bytes32 ticketId)

Interface

Implementation

Keepalive adds one lifetime period to the ticket's expiry
getBeneficiary(bytes32 ticketId)

Interface

Implementation

GetBeneficiary gets the beneficiary of the ticket
cancel(bytes32 ticketId)

Interface

Implementation

Cancel the ticket and refund its callvalue to its beneficiary
getCurrentRedeemer()

Interface

Implementation

Gets the redeemer of the current retryable redeem attempt
submitRetryable()

Interface

Implementation

Do not call. This method represents a retryable submission to aid explorers. Calling it will always revert.

EventSolidity interfaceGo implementationDescription
TicketCreated

Interface

Implementation

Emitted when creating a retryable
LifetimeExtended

Interface

Implementation

Emitted when extending a retryable's expiry date
RedeemScheduled

Interface

Implementation

Emitted when scheduling a retryable
Canceled

Interface

Implementation

Emitted when cancelling a retryable
Redeemed

Interface

Implementation

DEPRECATED in favour of new RedeemScheduled event after the nitro upgrade.

ArbStatistics

ArbStatistics (Interface | Implementation) provides statistics about the chain as of just before the Nitro upgrade. In Arbitrum Classic, this was how a user would get info such as the total number of accounts, but there are better ways to get that info in Nitro.

Precompile address: 0x000000000000000000000000000000000000006F

MethodSolidity interfaceGo implementationDescription
getStats()

Interface

Implementation

GetStats returns the current block number and some statistics about the rollup's pre-Nitro state

ArbSys

ArbSys (Interface | Implementation) provides system-level functionality for interacting with L1 and understanding the call stack.

Precompile address: 0x0000000000000000000000000000000000000064

MethodSolidity interfaceGo implementationDescription
arbBlockNumber()

Interface

Implementation

ArbBlockNumber gets the current L2 block number
arbBlockHash(uint256 arbBlockNum)

Interface

Implementation

ArbBlockHash gets the L2 block hash, if sufficiently recent
arbChainID()

Interface

Implementation

ArbChainID gets the rollup's unique chain identifier
arbOSVersion()

Interface

Implementation

ArbOSVersion gets the current ArbOS version
getStorageGasAvailable()

Interface

Implementation

GetStorageGasAvailable returns 0 since Nitro has no concept of storage gas
isTopLevelCall()

Interface

Implementation

IsTopLevelCall checks if the call is top-level (deprecated)
mapL1SenderContractAddressToL2Alias(address sender, address unused)

Interface

Implementation

MapL1SenderContractAddressToL2Alias gets the contract's L2 alias
wasMyCallersAddressAliased()

Interface

Implementation

WasMyCallersAddressAliased checks if the caller's caller was aliased
myCallersAddressWithoutAliasing()

Interface

Implementation

MyCallersAddressWithoutAliasing gets the caller's caller without any potential aliasing

withdrawEth(address destination)

Interface

Implementation

WithdrawEth send paid eth to the destination on L1
sendTxToL1(address destination, bytes calldata data)

Interface

Implementation

SendTxToL1 sends a transaction to L1, adding it to the outbox
sendMerkleTreeState()

Interface

Implementation

SendMerkleTreeState gets the root, size, and partials of the outbox Merkle tree state (caller must be the 0 address)

EventSolidity interfaceGo implementationDescription
L2ToL1Tx

Interface

Implementation

Logs a send transaction from L2 to L1, including data for outbox proving
L2ToL1Transaction

Interface

Implementation

DEPRECATED in favour of the new L2ToL1Tx event above after the nitro upgrade

SendMerkleUpdate

Interface

Implementation

Logs a new merkle branch needed for constructing outbox proofs

ArbWasm

ArbWasm (Interface | Implementation) provides helper methods for managing Stylus contracts

Precompile address: 0x0000000000000000000000000000000000000071

MethodSolidity interfaceGo implementationDescription
activateProgram(address program)

Interface

Implementation

Compile a wasm program with the latest instrumentation
stylusVersion()

Interface

Implementation

Gets the latest stylus version
codehashVersion(bytes32 codehash)

Interface

Implementation

Gets the stylus version that program with codehash was most recently compiled with
codehashKeepalive(bytes32 codehash)

Interface

Implementation

Extends a program's expiration date (reverts if too soon)
codehashAsmSize(bytes32 codehash)

Interface

Implementation

Gets a program's asm size in bytes
programVersion(address program)

Interface

Implementation

Gets the stylus version that program at addr was most recently compiled with
programInitGas(address program)

Interface

Implementation

Gets the cost to invoke the program
programMemoryFootprint(address program)

Interface

Implementation

Gets the footprint of program at addr
programTimeLeft(address program)

Interface

Implementation

Gets returns the amount of time remaining until the program expires
inkPrice()

Interface

Implementation

Gets the amount of ink 1 gas buys
maxStackDepth()

Interface

Implementation

Gets the wasm stack size limit
freePages()

Interface

Implementation

Gets the number of free wasm pages a tx gets
pageGas()

Interface

Implementation

Gets the base cost of each additional wasm page
pageRamp()

Interface

Implementation

Gets the ramp that drives exponential memory costs
pageLimit()

Interface

Implementation

Gets the maximum initial number of pages a wasm may allocate
minInitGas()

Interface

Implementation

Gets the minimum costs to invoke a program
initCostScalar()

Interface

Implementation

Gets the linear adjustment made to program init costs
expiryDays()

Interface

Implementation

Gets the number of days after which programs deactivate
keepaliveDays()

Interface

Implementation

Gets the age a program must be to perform a keepalive
blockCacheSize()

Interface

Implementation

Gets the number of extra programs ArbOS caches during a given block.
EventSolidity interfaceGo implementationDescription
ProgramActivated

Interface

Implementation

Emitted when activating a WASM program
ProgramLifetimeExtended

Interface

Implementation

Emitted when extending the expiration date of a WASM program

ArbWasmCache

ArbWasmCache (Interface | Implementation) provides helper methods for managing Stylus cache

Precompile address: 0x0000000000000000000000000000000000000072

MethodSolidity interfaceGo implementationDescription
isCacheManager(address manager)

Interface

Implementation

See if the user is a cache manager owner.
allCacheManagers()

Interface

Implementation

Retrieve all authorized address managers.
cacheCodehash(bytes32 codehash)

Interface

Implementation

Deprecated: replaced with CacheProgram.
cacheProgram(address addr)

Interface

Implementation

Caches all programs with a codehash equal to the given address. Caller must be a cache manager or chain owner.

evictCodehash(bytes32 codehash)

Interface

Implementation

Evicts all programs with the given codehash. Caller must be a cache manager or chain owner.

codehashIsCached(bytes32 codehash)

Interface

Implementation

Gets whether a program is cached. Note that the program may be expired.
EventSolidity interfaceGo implementationDescription
UpdateProgramCache

Interface

Implementation

Emitted when caching a WASM program