Debug Hyperlane Message Skill

When to Use

• User provides a message ID (e.g., 0xa454...) or explorer URL
• Investigating why a message is stuck or not delivered
• Debugging gas estimation failures
• Understanding message processing status

Input Parameters

Parameter	Required	Example	Description
message_id	Yes	0xa454559c...	The 66-character hex message ID
explorer_url	Optional	https://explorer.hyperlane.xyz/message/0x...	Can extract message_id from URL

Debugging Workflow

Step 1: Get Basic Message Details from Explorer

Fetch the explorer page to get origin/destination chains and basic status:

WebFetch: https://explorer.hyperlane.xyz/message/[MESSAGE_ID]
Prompt: Extract message status, origin chain, destination chain, sender, recipient, timestamp, delivery status

Key info to extract:

• Origin chain and domain ID
• Destination chain and domain ID
• Is it delivered? (if yes, no debugging needed)
• Timestamp (how old is it?)

Step 2: Search Relayer Logs for the Message

Use the gcloud CLI to find logs related to this message in the omniscient relayer:

gcloud logging read 'resource.type="k8s_container" AND resource.labels.project_id="abacus-labs-dev" AND resource.labels.location="us-east1-c" AND resource.labels.cluster_name="hyperlane-mainnet" AND resource.labels.namespace_name="mainnet3" AND labels.k8s-pod/app_kubernetes_io/component="relayer" AND labels.k8s-pod/app_kubernetes_io/instance="omniscient-relayer" AND labels.k8s-pod/app_kubernetes_io/name="hyperlane-agent" AND "[MESSAGE_ID]"' --project=abacus-labs-dev --limit=50 --format=json --freshness=1d

Step 3: Identify the Message Status

Look for the message in PendingMessage entries. Common statuses:

Status	Meaning	Priority
Retry(ErrorEstimatingGas)	Gas estimation failing - contract revert	HIGH
Retry(GasPaymentRequirementNotMet)	Insufficient gas payment	MEDIUM
Retry(CouldNotFetchMetadata)	Validator signatures unavailable	LOW (check after 5+ min)
FirstPrepareAttempt	Still processing, not stuck yet	LOW

Extract status with:

grep -o "message_id: [MESSAGE_ID][^}]*" [log_output] | sort -u

Step 4: Check for Gas Payment Issues

If message is slow/stuck, search for gas payment evaluation logs:

gcloud logging read '[BASE_RELAYER_QUERY] AND "[MESSAGE_ID]" AND jsonPayload.fields.message:"Evaluating if message meets gas payment requirement"' --project=abacus-labs-dev --limit=5 --format=json --freshness=7d

Key fields in jsonPayload.fields:

• current_payment.gas_amount - gas units paid for by sender
• tx_cost_estimate.gas_limit - gas units needed for delivery
• current_expenditure.gas_used - gas already spent on retries
• policy - subsidy policy (e.g., fractional_numerator: 1, fractional_denominator: 2 = 50% subsidy)

If gas_amount < gas_limit, message fails with "Repreparing message: Gas payment requirement not met" and retries every ~3 minutes.

Step 5: For Gas Estimation Errors - Get the Revert Reason

If status is ErrorEstimatingGas, the actual revert reason is in jsonPayload.fields.error. Use this query and extraction:

# Query logs with error field
gcloud logging read 'resource.type="k8s_container" AND resource.labels.project_id="abacus-labs-dev" AND resource.labels.location="us-east1-c" AND resource.labels.cluster_name="hyperlane-mainnet" AND resource.labels.namespace_name="mainnet3" AND labels.k8s-pod/app_kubernetes_io/component="relayer" AND labels.k8s-pod/app_kubernetes_io/instance="omniscient-relayer" AND labels.k8s-pod/app_kubernetes_io/name="hyperlane-agent" AND "[MESSAGE_ID]" AND jsonPayload.fields.error:*' --project=abacus-labs-dev --limit=5 --format=json --freshness=1d 2>/dev/null | grep -o '"error": "[^"]*"' | head -1

The error field contains the full revert reason, e.g.:

"error": "ContractError(...JsonRpcError { code: 3, message: \"execution reverted: panic: arithmetic underflow or overflow (0x11)\", data: Some(...) }...)"

Quick extraction - pipe to extract just the revert message:

... | grep -oP 'execution reverted: [^"\\]+' | head -1

Common revert patterns:

• execution reverted: panic: arithmetic underflow or overflow (0x11) - Contract math error
• execution reverted: [CUSTOM_ERROR] - Custom contract revert (decode with cast 4byte)
• execution reverted with hex data - Decode selector with cast 4byte 0x[first4bytes]

Step 6: Extract Message Details

From the logs, identify:

• origin: Source chain
• destination: Destination chain (or domain ID like 4114 for Citrea)
• sender: Origin contract address
• recipient: Destination contract address (the warp route or recipient)
• nonce: Message sequence number

Example log format:

HyperlaneMessage { id: 0x..., nonce: 162898, origin: ethereum, sender: 0x..., destination: 4114, recipient: 0x... }

Step 7: Report Findings

Summarize:

1. Message ID: Full ID
2. Route: Origin -> Destination (e.g., Ethereum -> Citrea)
3. Status: Current processing status
4. Root Cause: The actual error (e.g., contract revert reason)
5. Retry Count: How many times it's been attempted
6. Recommendation: What needs to happen (e.g., fix recipient contract, wait for validators)

Common Root Causes

Gas Estimation Errors

Error	Meaning	Resolution
panic: arithmetic underflow or overflow (0x11)	Contract math error	Bug in recipient contract
IXERC20_NotHighEnoughLimits()	Bridge rate limit hit	Wait for limit reset
InsufficientBalance	Not enough tokens	Fund the contract
Unauthorized	Access control failure	Check permissions

Metadata/Validator Issues

If CouldNotFetchMetadata persists > 5 minutes:

1. Check validator status using the debug-validator-checkpoint-inconsistency skill
2. Identify if validators are behind on the origin chain

Gas Payment Issues

If GasPaymentRequirementNotMet:

• Compare current_payment.gas_amount vs tx_cost_estimate.gas_limit
• Message will auto-retry every ~3 min until gas prices drop or subsidy kicks in
• Check policy field for subsidy ratio (e.g., 1/2 = relayer covers 50%)
• Resolution: wait for gas prices to drop, or manually subsidize via IGP top-up

Decoding Revert Selectors

When you see hex revert data like 0x4e487b71...:

cast 4byte 0x4e487b71
# Returns: Panic(uint256)

Common panic codes:

• 0x11 - Arithmetic overflow/underflow
• 0x12 - Division by zero
• 0x21 - Invalid enum value
• 0x31 - Pop on empty array
• 0x32 - Array out of bounds

Domain ID Reference

Common domain IDs (destination field in logs):

• 1 - Ethereum
• 42161 - Arbitrum
• 10 - Optimism
• 137 - Polygon
• 4114 - Citrea

Check @hyperlane-xyz/registry or chain metadata for full mapping.

Example Investigation

User asks: "Why isn't message 0xa454... being processed?"

1. Fetch explorer: Origin=Ethereum, Dest=Citrea, not delivered
2. Query relayer logs for 0xa454...
3. Find status: Retry(ErrorEstimatingGas)
4. Search error logs: execution reverted: panic: arithmetic underflow or overflow (0x11)
5. Report: "Message from Ethereum to Citrea is failing because the recipient contract (0xbd39...) on Citrea is reverting with an arithmetic overflow error. This is a bug in the destination contract that needs to be fixed by the contract owner."