DAC configuration defaults

Default settings for a Data Availability Committee (AnyTrust) chain as defined in the Arbitrum Orbit SDK.

• src/prepareChainConfig.ts
• src/prepareNodeConfig.ts
• src/types/NodeConfig.generated.ts

Chain config defaults

Set at rollup creation time.

{
  "arbitrum": {
    "EnableArbOS": true,
    "AllowDebugPrecompiles": false,
    "DataAvailabilityCommittee": false,
    "InitialArbOSVersion": 51,
    "GenesisBlockNum": 0,
    "MaxCodeSize": 24576,
    "MaxInitCodeSize": 49152
  }
}

To enable DAC, override DataAvailabilityCommittee to true at deployment:

prepareChainConfig({
  chainId: 12345,
  arbitrum: {
    InitialChainOwner: '0x...',
    DataAvailabilityCommittee: true,
  },
});

Node config defaults (when DAC is enabled)

Generated by prepareNodeConfig() when chainConfig.arbitrum.DataAvailabilityCommittee is true.

{
  "node": {
    "data-availability": {
      "enable": true,
      "sequencer-inbox-address": "<from coreContracts>",
      "parent-chain-node-url": "<from parentChainRpcUrl>",
      "rest-aggregator": {
        "enable": true,
        "urls": ["http://localhost:9877"]
      },
      "rpc-aggregator": {
        "enable": true,
        "assumed-honest": 1,
        "backends": "[{\"url\":\"http://localhost:9876\",\"pubkey\":\"YAAA...AAA==\",\"signermask\":1}]"
      }
    },
    "batch-poster": {
      "enable": true,
      "max-size": 90000,
      "parent-chain-wallet": {
        "private-key": "<batchPosterPrivateKey>"
      }
    }
  }
}

Full default values reference

Every DAC-related setting with its documented default, organized by config section.

node.data-availability

Key	Default	Description
enable	false	Enable AnyTrust Data Availability mode
panic-on-error	false	Fail immediately on DAS errors (not recommended)
parent-chain-connection-attempts	15	Parent chain RPC retries (standalone daserver only; 0 = infinite)
parent-chain-node-url	—	Parent chain RPC URL (standalone daserver only)
request-timeout	5s	Timeout for Store requests
sequencer-inbox-address	—	SequencerInbox contract address on parent chain

node.data-availability.rest-aggregator

Key	Default	Description
enable	false	Enable REST retrieval of batch data
max-per-endpoint-stats	20	Latency/success-rate stats entries per endpoint
online-url-list	—	URL to a remote list of REST DAS endpoint URLs
online-url-list-fetch-interval	1h0m0s	How often to re-fetch the online URL list
strategy	simple-explore-exploit	Endpoint selection strategy
strategy-update-interval	10s	How often to refresh strategy with latency/error data
urls	[]	Static list of REST DAS endpoint URLs
wait-before-try-next	2s	Time before trying the next set of REST endpoints

node.data-availability.rest-aggregator.simple-explore-exploit-strategy

Key	Default	Description
exploit-iterations	1000	Consecutive GetByHash calls using best-latency endpoints before switching to explore
explore-iterations	20	Consecutive GetByHash calls using random endpoints before switching to exploit

node.data-availability.rest-aggregator.sync-to-storage

Key	Default	Description
delay-on-error	1s	Wait time before retrying after sync error
eager	false	Eagerly sync batch data using L1 as index (vs lazy)
eager-lower-bound-block	—	Starting L1 block for eager sync (only if no prior state)
ignore-write-errors	true	Log-only on write failures during sync
parent-chain-blocks-per-read	100	Max L1 blocks to read per eager sync poll
retention-period	360h0m0s	How long to retain synced data
state-dir	—	Directory to persist sync progress
sync-expired-data	true	Sync expired data (needed for mirror configs)

node.data-availability.rpc-aggregator

Key	Default	Description
assumed-honest	—	H value; required signatures K = N + 1 - H
backends	null	JSON array of {url, pubkey, signermask} objects
enable	false	Enable RPC storage of batch data (batch poster only)

node.data-availability.rpc-aggregator.das-rpc-client

Key	Default	Description
enable-chunked-store	true	Send data to DAS in chunks instead of all at once
server-url	—	DAS server URL

node.data-availability.rpc-aggregator.das-rpc-client.data-stream

Key	Default	Description
max-store-chunk-body-size	5242880 (5 MB)	Maximum HTTP body size per chunk

node.data-availability.rpc-aggregator.das-rpc-client.data-stream.rpc-methods

Key	Default	Description
finalize-stream	das_commitChunkedStore	RPC method to finalize a chunked store session
start-stream	das_startChunkedStore	RPC method to initiate a chunked store session
stream-chunk	das_sendChunk	RPC method to send a data chunk

node.batch-poster (DAC-relevant settings)

Key	Default	Description
das-retention-period	360h0m0s	Period DASes retain stored batches in AnyTrust mode
disable-dap-fallback-store-data-on-chain	false	If true, disables fallback to on-chain batch posting when DA fails
enable	false	Enable batch posting
max-size	100000	Maximum estimated compressed batch size (bytes)
error-delay	10s	Delay after batch posting error before retry
extra-batch-gas	50000	Extra gas added to batch posting estimate
max-delay	1h0m0s	Maximum batch posting delay
max-empty-batch-delay	72h0m0s	Maximum delay before posting an empty batch
poll-interval	10s	Interval to check for ready batches
check-batch-correctness	true	Verify batch against inbox multiplexer
compression-level	11	Batch compression level
l1-block-bound-bypass	1h0m0s	Post even if outside L1 bounds, within this margin
delay-buffer-always-updatable	true	Always treat delay buffer as updatable
delay-buffer-threshold-margin	25	Blocks before delay buffer threshold to post batch

node.da-provider (Newer DAProvider interface)

Key	Default	Description
enable	false	Enable DAProvider client
store-rpc-method	daprovider_store	Single-shot store RPC method name
use-data-streaming	false	Use chunked streaming protocol for large payloads
with-writer	false	DAProvider server supports writer interface

node.da-provider.data-stream

Key	Default	Description
max-store-chunk-body-size	5242880 (5 MB)	Maximum HTTP body size per chunk

node.da-provider.data-stream.rpc-methods

Key	Default	Description
finalize-stream	daprovider_commitChunkedStore	RPC method to finalize a chunked store session
start-stream	daprovider_startChunkedStore	RPC method to initiate a chunked store session
stream-chunk	daprovider_sendChunk	RPC method to send a data chunk

node.da-provider.rpc

Key	Default	Description
arg-log-limit	2048	Limit size of arguments in log entries
retries	3	Retries on failure (0 = one attempt)
retry-errors	websocket: close.*|dial tcp .*|.*i/o timeout|.*connection reset by peer|.*connection refused	Regex for auto-retried errors
websocket-message-size-limit	268435456 (256 MB)	WebSocket message size limit

SDK-applied defaults(prepareNodeConfig)

When prepareNodeConfig() detects DataAvailabilityCommittee: true, it applies these concrete values. Source: src/prepareNodeConfig.ts:158-182

Setting	Value Applied	Notes
data-availability.enable	true	Overrides the false default
data-availability.sequencer-inbox-address	coreContracts.sequencerInbox	From deployment output
data-availability.parent-chain-node-url	parentChainRpcUrl	From params
rest-aggregator.enable	true	Overrides the false default
rest-aggregator.urls	["<dasServerUrl>:9877"]	Falls back to http://localhost:9877
rpc-aggregator.enable	true	Overrides the false default
rpc-aggregator.assumed-honest	1	Single honest member (dev default)
rpc-aggregator.backends	JSON with 1 backend	URL at <dasServerUrl>:9876, signermask 1
batch-poster.enable	true	—
batch-poster.max-size	90000	Lower than the NodeConfig default of 100000