Enterprise operations teams managing high-value Safe deployments cannot rely solely on the Safe{Wallet} interface or periodic manual checks. A production-grade monitoring architecture must ingest on-chain events—SafeSetup, ExecutionSuccess, ExecutionFailure, AddedOwner, ChangedThreshold, EnabledModule, and DisabledModule—to maintain a real-time, deterministic view of every Safe's security posture and transaction lifecycle. Without this, teams risk operating with an outdated understanding of signer sets, module permissions, or pending failure states that could delay critical remediation.

Monitoring Safe Events and State Changes for Enterprise Operations
Introduction
A technical framework for enterprise and custodian teams to build robust monitoring systems that track on-chain state changes, off-chain signature collection, and anomalous module interactions for production Safe smart accounts.
The operational surface extends beyond emitted logs. Effective monitoring correlates on-chain state changes with off-chain signature collection progress, tracking the gap between a proposed safeTxHash and the accumulation of confirmations toward the required threshold. Anomaly detection rules must flag unexpected DelegateCall operations, interactions with unregistered modules, or transactions originating from unrecognized relayers, as these patterns often precede security incidents. For institutional custodians integrating MPC or HSM-based signing, monitoring must also verify that the approvedHashes mapping and EIP-712 domain separator remain consistent with the expected signing ceremony and chain context.
Chainscore Labs designs monitoring architectures that transform raw Safe event streams into actionable alerting rules for security operations centers. This includes defining severity levels for threshold changes, building idempotent event-processing pipelines that handle chain reorganizations, and creating dashboards that surface the real-time state of every Safe in a fleet. For teams managing Safes across multiple EVM chains, we ensure that cross-chain replay protection and chain-specific singleton addresses are incorporated into the monitoring model, preventing false positives from legitimate multi-chain activity.
Quick Facts: Safe Monitoring Surface
What this table helps the reader evaluate
| Area | What changes | Who is affected | Action |
|---|---|---|---|
SafeSetup and AddedOwner events | Ownership threshold or signer set is modified | Custodians, security teams, compliance officers | Alert on any AddedOwner or ChangedThreshold event; verify against authorized change requests |
ExecutionSuccess and ExecutionFailure events | A transaction executes or reverts on-chain | Treasury operators, DAO tooling, risk teams | Monitor for unexpected ExecutionFailure with GS0XX error codes; investigate root cause immediately |
Module transactions via execTransactionFromModule | A module initiates a transaction bypassing the multisig confirmation flow | Security engineers, protocol architects | Alert on all execTransactionFromModule calls; correlate with known module behavior and authorized operations |
Delegatecall operations (Operation enum = 1) | A transaction executes in the Safe's own context, risking storage corruption | Module developers, security auditors | Flag all delegatecall executions; verify target is a trusted module or the Safe itself; review for context hijacking risks |
Fallback handler changes (ChangedFallbackHandler event) | The fallback handler address is updated, altering token callbacks or ERC-4337 behavior | Wallet integrators, operations teams | Monitor for unexpected handler changes; validate new handler address against canonical deployments for the Safe version |
Off-chain signature collection via Transaction Service API | Signatures are collected off-chain and indexed; eventual consistency may delay confirmation visibility | Custody platforms, automated relayers | Monitor API health and indexer lag; implement direct contract polling as a fallback for critical transactions |
Nonce sequence gaps or stuck transactions | A pending transaction with a lower nonce blocks all subsequent transactions in the queue | Algorithmic traders, DAO operators | Alert on nonce gaps exceeding a time threshold; have a procedure to cancel or replace the blocking transaction |
Event Taxonomy and State Change Semantics
A precise classification of Safe's on-chain events and state transitions that enterprise monitoring systems must track to detect anomalies, confirm execution, and maintain a verifiable audit trail.
Enterprise monitoring for Safe smart accounts begins with a rigorous taxonomy of emitted events and their corresponding state changes. The canonical GnosisSafe and SafeL2 contracts emit a structured set of events that form the basis for all operational alerting: SafeSetup (initialization), AddedOwner and RemovedOwner (signer-set mutations), ChangedThreshold (policy modification), ExecutionSuccess and ExecutionFailure (transaction finality), ApproveHash (pre-approval of a transaction hash), SignMsg (off-chain signature commitment), and ChangedFallbackHandler and ChangedGuard (security module reconfiguration). Each event is a discrete, indexable log that allows an operator to reconstruct the full lifecycle of a Safe and its transactions without relying on the Transaction Service API.
The operational significance of these events lies in their relationship to Safe's storage state. For example, an AddedOwner event is only valid if the subsequent getOwners() call reflects the new owner set and the linked SafeSetup or ExecutionSuccess event confirms the originating transaction. A ChangedThreshold event that does not correspond to a prior execTransaction call with the correct nonce is a critical anomaly. Similarly, an ExecutionFailure event with a GS0XX revert reason requires immediate correlation with the failing execTransaction trace to determine whether the root cause is a gas accounting error (GS000), an invalid signature (GS021), or a guard rejection. Monitoring systems must not treat events in isolation; they must verify that each event represents a valid state transition by cross-referencing the Safe's storage at the block height of the event.
For enterprise deployments, the event taxonomy must also account for module and guard interactions. A SafeModuleTransaction event from an enabled module can alter the Safe's state without a direct execTransaction call, making it essential to monitor ExecutionFromModuleSuccess and ExecutionFromModuleFailure events. A guard that reverts a transaction will prevent an ExecutionSuccess event, but the attempted state change may still be visible in a trace. Chainscore Labs designs monitoring architectures that map this full event taxonomy to enterprise SIEM systems, constructing alerting rules that detect owner-set drift, unexpected threshold changes, and module-initiated state transitions that bypass the standard multisig confirmation flow.
Affected Teams and Systems
Custody & Treasury Operations
Enterprise custody teams must monitor for unauthorized state changes that could indicate a compromise or insider threat. Key signals include unexpected AddedOwner or ChangedThreshold events, which can alter the signing power structure without a corresponding governance proposal.
Operational checklist:
- Alert on any
AddedOwnerorRemovedOwnerevent that does not match a known, approved change window. - Monitor
ChangedThresholdevents to detect threshold reductions that could weaken security. - Track
ExecutionFailureevents to identify stuck or reverted treasury operations before they cause settlement failures. - Correlate
SafeSetupevents with your internal Safe deployment records to detect unauthorized proxy deployments.
Chainscore can design a monitoring architecture that maps Safe events to your internal change-management workflows, ensuring no state change goes unreviewed.
Monitoring Architecture and Alerting Rules
A robust monitoring architecture is essential for enterprise operators to detect anomalies, track state changes, and ensure the integrity of Safe transactions. This framework defines critical on-chain events, off-chain signals, and alerting rules for production deployments.
Critical On-Chain Event Monitoring
Ingest and alert on core Safe events: SafeSetup for initial configuration verification, ExecutionSuccess and ExecutionFailure for transaction lifecycle tracking, and AddedOwner/RemovedOwner for unauthorized signer changes. Monitor ChangedThreshold and EnabledModule/DisabledModule events to detect unexpected security parameter modifications. Each event must be correlated with msg.sender and block context to distinguish legitimate operations from anomalies. Chainscore can design event ingestion pipelines and severity-based alerting rules tailored to your Safe's governance model.
Off-Chain Signature Collection Alerts
Monitor the Safe Transaction Service API for signature collection progress toward the confirmation threshold. Alert on stalled transactions where the required number of confirmations has not been met within a defined SLA, indicating signer unavailability or a blocked queue. Track safeTxGas estimation failures that prevent signers from submitting valid signatures. For high-value Safes, implement a secondary check that verifies the Transaction Service's state against on-chain approvedHashes to detect indexer lag or data inconsistency that could mask a partially signed transaction.
Module and Guard Interaction Anomaly Detection
Establish a behavioral baseline for each enabled module and guard. Monitor for unexpected execTransactionFromModule calls, delegatecall operations from unverified contracts, or guard reverts that could indicate an exploit attempt or misconfiguration. Alert on any module interaction that targets a non-whitelisted external contract. For Safes using the Safe4337Module, monitor UserOperation bundling failures and paymaster sponsorship rejections. Chainscore can build anomaly detection models that learn normal Safe behavior and flag deviations before they result in asset loss.
Nonce Queue and Transaction Ordering Monitoring
Track the Safe's current nonce and the status of all pending transactions in the queue. A stuck transaction at nonce N blocks all subsequent transactions, creating an operational deadlock. Alert when a transaction remains pending beyond a configurable time window. Monitor for nonce gaps that could indicate a skipped transaction or a front-running attempt. For high-frequency Safes, implement a dashboard that visualizes the transaction queue and highlights the oldest pending transaction. Chainscore can design nonce-management dashboards and automated queue-unblocking procedures.
Relayer and Gas Network Dependency Monitoring
If using a relayer for gasless transactions, monitor relayer liveness, gas price spikes, and transaction submission latency. Alert on relayer non-responsiveness or a high rate of ExecutionFailure events with gas-related revert codes (GS000). Track the relayer's ETH balance to prevent exhaustion. For teams operating custom relayers, monitor mempool inclusion times and alert on transactions that remain unconfirmed beyond the expected block time. Chainscore can evaluate relayer resilience and recommend redundant relayer architectures to eliminate single points of failure.
Cross-Chain Safe State Reconciliation
For Safes deployed on multiple chains with the same address, implement a reconciliation process that compares the owner set, threshold, modules, and fallback handler across all deployments. Alert on any divergence, which could indicate a partial migration, a chain-specific attack, or an operational error. Monitor the chainId in EIP-712 signatures to ensure replay protection is intact. Chainscore can build cross-chain state verification tools that continuously audit configuration consistency and flag drift before it becomes a security incident.
Risk Matrix: Monitoring Gaps and Consequences
Evaluates the operational risks introduced by gaps in monitoring Safe events and state changes, identifying affected teams and recommended actions for enterprise deployments.
| Risk Area | Failure Mode | Severity | Affected Actors | Mitigation Action |
|---|---|---|---|---|
Owner Set Changes | Unmonitored AddedOwner or RemovedOwner events allow unauthorized signer changes to go undetected, leading to a full compromise of the Safe. | Critical | Custodians, Security Engineers, DAO Operators | Implement real-time alerts on AddedOwner and RemovedOwner events. Reconcile owner set against an authorized list hourly. |
Threshold Modifications | A ChangedThreshold event is missed, allowing a single malicious signer to execute transactions if the threshold is silently lowered to 1. | Critical | Custodians, Treasury Managers, Risk Teams | Monitor ChangedThreshold events and trigger an immediate pager alert if the new threshold deviates from the governance-approved value. |
Module and Guard Changes | An attacker or rogue signer enables a malicious module via EnabledModule or disables a critical security guard via ChangedGuard without detection. | High | Security Engineers, Protocol Architects, Auditors | Alert on any EnabledModule or ChangedGuard event. Maintain an on-chain allowlist of known, audited module addresses and alert on any deviation. |
Transaction Execution Failures | Recurring ExecutionFailure events with GS0XX error codes are not tracked, masking a systematic integration issue that blocks all withdrawals. | High | Operations Teams, Wallet Integrators, DAO Tooling | Aggregate ExecutionFailure events by error code. Set a threshold for failures within a time window to detect integration bugs or relayer misconfiguration. |
Indexer and API Lag | The Safe Transaction Service API experiences lag or downtime, causing off-chain signature collection to stall and transactions to appear stuck in the UI. | Medium | Operations Teams, Frontend Developers, Custodians | Monitor the health and block latency of the Transaction Service API. Implement a fallback procedure using the Safe SDK to broadcast packed signatures directly. |
Delegatecall Operations | A transaction with Operation=DelegateCall is executed without explicit review, potentially hijacking the Safe's execution context to call a malicious contract. | High | Security Engineers, Module Developers, Auditors | Create a dedicated monitoring rule that flags every DelegateCall transaction for mandatory manual review before it is considered successfully executed. |
Nonce Queue Blocking | A pending transaction at nonce N is not monitored for confirmations, blocking all subsequent transactions and freezing treasury operations. | Medium | Treasury Managers, DAO Operators, Automated Bots | Monitor the age and confirmation count of the lowest pending nonce. Alert if it remains unconfirmed beyond a defined SLA, triggering an escalation to signers. |
Operator Checklist: Deploying Safe Monitoring
A structured checklist for enterprise and custodian teams to verify that their monitoring infrastructure captures the full lifecycle of Safe operations, from signature collection to execution and state changes. Each item includes the signal to monitor, why it matters, and the artifact that confirms readiness.
What to check: Confirm that your monitoring system indexes and alerts on the SafeSetup event (emitted during initial deployment) and ChangedFallbackHandler, EnabledModule, DisabledModule, AddedOwner, and RemovedOwner events.
Why it matters: These events define the security perimeter of the Safe. An unexpected AddedOwner or EnabledModule is a critical security signal that may indicate a compromised owner key or an unauthorized configuration change. Without monitoring these, a breach can go undetected until funds are moved.
Readiness signal: A test transaction that adds and removes a known address triggers an alert within your defined latency window (e.g., < 2 minutes).
Source Resources and Canonical References
Use these canonical resources to build Safe monitoring that reconciles on-chain events, indexed transaction data, deployment authenticity, and signing-state assumptions. Enterprise teams should treat RPC logs and verified contract ABIs as the source of truth, with APIs and SDKs used for enrichment and workflow automation.
Looking to build on a specific blockchain?
We build smart contracts, DeFi applications, wallets, tokenization platforms, and blockchain infrastructure across the major ecosystems teams choose today. That includes Ethereum, Arbitrum, Optimism, Polygon, Avalanche, Solana, Sui, Aptos, Hedera, Stellar, and NEAR, with support for additional EVM and non-EVM networks based on your product requirements.
EVM ecosystems
- Ethereum
- Arbitrum
- Optimism
- Polygon
- Avalanche
- Cronos

Non-EVM ecosystems
- Solana
- Sui
- Aptos
- Hedera
- Stellar
- NEAR
Additional ecosystems
- Polkadot
- Cosmos
- TON
- Cardano
- Algorand
- Tempo
Also available for Base, appchains, custom EVM networks, and cross-chain product architecture.
Frequently Asked Questions
Answers to common questions from enterprise and custodian teams building monitoring systems for Safe smart accounts.
At minimum, monitor these core Safe contract events:
-
SafeSetup(address indexed initiator, address[] owners, uint256 threshold, address initializer, address fallbackHandler): Emitted once during Safe creation. Captures the initial owner set and threshold. Use this to baseline the expected security configuration.
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ExecutionSuccess(bytes32 txHash, uint256 payment): Emitted when a transaction executes successfully. The txHash is the Safe transaction hash, not the Ethereum transaction hash. Track this to confirm intended operations completed.
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ExecutionFailure(bytes32 txHash, uint256 payment): Emitted when execTransaction reverts. Critical for alerting—every failure should trigger an investigation. The payment field shows gas spent even on failure.
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AddedOwner(address indexed owner): Emitted when an owner is added via addOwnerWithThreshold. Unexpected owner additions are a high-severity signal.
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RemovedOwner(address indexed owner): Emitted when an owner is removed. Correlate with expected governance actions.
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ChangedThreshold(uint256 threshold): Emitted when the signing threshold changes. Threshold reductions without corresponding governance activity warrant immediate attention.
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ChangedFallbackHandler(address handler): Emitted when the fallback handler is updated. A malicious or misconfigured handler can hijack Safe behavior.
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ChangedGuard(address guard): Emitted when the transaction guard changes. Guards can block or modify transactions, so unexpected guard changes are a critical alert.
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EnabledModule(address module) / DisabledModule(address module): Modules have full delegatecall access to the Safe. Monitor all module enable/disable events and verify against an allowlist.
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ApproveHash(bytes32 approvedHash, address indexed owner): Emitted when an owner approves a hash on-chain. Useful for tracking confirmation progress toward threshold.
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SignMsg(bytes32 msgHash): Emitted when signMessage is called. Track for off-chain message signing activity.
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SafeReceived(address indexed sender, uint256 value): Emitted on direct ETH transfers. Monitor for unexpected inbound value that could indicate a phishing or dusting attempt.
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ExecutionFromModuleSuccess(address indexed module) / ExecutionFromModuleFailure(address indexed module): Emitted when a module executes a transaction via execTransactionFromModule. Module-initiated executions bypass the normal multisig flow and require separate monitoring.
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