Arbitrum’s delayed inbox can bypass a stalled sequencer

Arbitrum permits anyone to force an eligible parent-to-L2 message past a stalled sequencer after its delay; L2 withdrawals use a separate on-chain path. Arbitrum’s Nitro whitepaper describes a 24-hour threshold for forcing a message from its Delayed Inbox into the chain’s queue.

The distinction matters because “bridge message” can mean a deposit or instruction sent from a parent chain to an L2, or a withdrawal initiated on the L2 and claimed on its parent. Arbitrum Docs describe force inclusion as a route through the parent chain’s Delayed Inbox that bypasses the sequencer. A guide to Manta bridge routes and wallet choices covers route selection; the mechanism below is specific to Arbitrum-style delayed inboxes.

What does force inclusion do?

Force inclusion advances an eligible queued message without asking the sequencer to include it. Arbitrum Docs say parent-chain messages can submit child-chain transactions, deposits, or instructions; the sequencer normally orders them, while force inclusion provides a fallback if it censors them or stops operating.

It does not make an arbitrary bridge transfer happen immediately. The message must already have been submitted to the correct Delayed Inbox, become eligible under that chain’s rules, and still be valid when processed. On Arbitrum, a parent-to-child retryable ticket may also need a separate redemption attempt if its automatic execution fails, according to Arbitrum Docs.

How do you force-include a delayed message?

Start with the parent-chain transaction hash for the deposit or instruction. Use the chain’s explorer and documentation to confirm that the transaction succeeded, identify the message in the Delayed Inbox, and check the eligibility window for that specific chain. The 24-hour period in Arbitrum’s Nitro whitepaper is not a universal timer for every L2.

• Confirm the source transaction is on the correct parent chain and reached the intended inbox.
• Check whether the message has already appeared on the L2 or remains queued.
• Verify that the chain’s documented force-inclusion delay has elapsed.
• Use the chain’s documented contract interface or supported tool to submit the force-inclusion call, and review the target contract and transaction details before signing.

Arbitrum’s documentation identifies the Sequencer Inbox’s force-inclusion function as the censorship-resistant path, but contract addresses and call details depend on the chain. The action requires a parent-chain transaction and its gas; it advances the delayed queue, so an earlier queued message may be processed first. Check the resulting parent-chain receipt and the L2 transaction record to confirm inclusion and execution separately.

Can this release an L2-to-parent withdrawal?

No: force-including a Delayed Inbox message concerns parent-to-child traffic. Arbitrum Docs describe L2-to-parent withdrawals as a separate flow: the message is initiated on the L2, then claimed through the Outbox after its rollup block is confirmed and the required proof is available.

For most users, the better first step is to identify which side of the bridge holds the unprocessed message, then follow that chain’s documented recovery path. A queued parent-to-L2 message may qualify for force inclusion; a pending L2 withdrawal needs its own proof and claim steps. The chain’s eligibility window and the message’s current status still need to be confirmed before acting.