Monitoring Smart Contracts: Forta vs. Tenderly — what actually prevents incidents, satisfies SOC 2 evidence, and delivers measurable ROI in production. Below is a pragmatic blueprint (for Enterprise teams) showing when to use which tool, how to wire them into your SIEM and runbooks, and how to defend budgets in procurement.

Monitoring Smart Contracts: Forta vs. Tenderly

Enterprise (Fintech, Exchanges, Custody). Keywords intentionally included: SOC 2, SIEM, SLAs, RTO/RPO, audit trail, incident response, procurement.

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Pain

You’re rolling out Solidity contracts across multiple EVM chains and your audit is signed off—but your execs still ask: “What will page us first, and who auto-responds while we’re asleep?” Today, you likely have:

• Event-only monitors that miss mempool/pre-inclusion threats.
• A noisy alert pipe without severity routing into your SIEM (Splunk, Datadog), no “one-click pause” playbooks, and no chain-of-custody for compliance.
• A dependency on legacy vendor glue that’s in maintenance and scheduled to shut down, forcing rushed migrations mid-roadmap, with procurement pushing for SOC 2 evidence and SLAs your stack can’t prove yet. (docs.openzeppelin.com)

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Agitation

• Post-transaction detection is too late for real exploits. Pre-inclusion screening at the sequencer or contract gate is becoming table stakes; without it, the best you can offer is “rapid forensics,” not prevention. Forta’s Firewall module exists precisely because teams were losing hours to “after-the-fact” response. (docs.forta.network)
• Your monitoring vendor mix may be brittle. Defender’s maintenance mode and 2026-07-01 shutdown date mean Forta-Defender pathways need a migration plan now, not during an incident. Expect rework and delayed feature launches if you ignore it. (docs.openzeppelin.com)
• Attackers already exploit “simulated” UX. Tenderly’s Simulation RPC is powerful—and scammers use lookalike simulation endpoints to trick users into believing fake balances and “pending” transfers are real. Your support team pays the reputational and operational cost unless you gate RPCs and educate users. (reddit.com)
• Missing SOC 2 evidence. Procurement wants runbooks, alert destinations, webhook signatures, change logs, and audit trails traceable to SIEM with documented SLAs and RTO/RPO assertions. If your alerting can’t prove delivery, you’ll fail the control. (help.splunk.com)

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Solution

What we deploy at 7Block Labs: a dual-plane monitoring design that embraces the strengths of both Forta and Tenderly—and meets Enterprise auditability.

1. Strategy & Procurement Alignment (2–3 weeks)

• Map SOC 2 controls to the chain stack: logging scope, data retention, webhook auth (HMAC/Bearer), and evidence collection. Configure alert destinations that land in Splunk or your SIEM via allow-listed webhooks and signed payloads. 

• Define availability SLAs and target RTO/RPO. For example, “<5 minutes MTTD for high-severity threats; <15 minutes MTTR through auto-playbooks.” 

• Outcome: a requirements matrix your procurement team can approve, plus a monitoring architecture doc and a runbook index.

1. The Monitoring Fabric (Forta + Tenderly)

• Forta for Threat Intel and Pre-Inclusion Screening:

  • Subscribe to network feeds and premium bots via GraphQL/push channels (email, Slack, Telegram, Discord, webhook). Configure filters per bot ID or contract address in the Forta App. (docs.forta.network)
  • Adopt Forta v2 Bot SDK for protocol-specific detections (handleBlock, handleTransaction, handleAlert) across any EVM chain. This unlocks alert composability—your custom bots can consume other bots’ alerts via handleAlert. (docs.forta.network)
  • Where you control a rollup or critical protocol gateway, integrate Forta Firewall to screen and block high-risk transactions pre-sequencer using AI risk scoring (FORTRESS). Metrics publicly disclosed: >99% exploit recall, <0.0002% false positives, sub-~60–80ms decision latency at the sequencer. (docs.forta.network)
  • Record-keeping and censorship resistance are handled on Forta Chain (Arbitrum Orbit L3). Use that on-chain log (encrypted, chain ID 80931) as your auditable trail of screened/blocked transactions. (docs.forta.network)
  • Subscriptions: budget the General Plan (250 FORT/month) for wide coverage; premium feeds are add-ons. Payments via Unlock Protocol in USDC or FORT; unlimited API calls per plan. This is easy to justify in procurement with transparent on-chain billing. (docs.forta.network)

• Tenderly for Observability, Simulation, and Automation:

  • Real-time monitoring and alerting with destinations to Slack, Telegram, Discord, PagerDuty, webhooks—and serverless Web3 Actions for automatic response. (tenderly.co)
  • Node RPC with enterprise-grade performance claims: up to 99.99% uptime SLA, <100ms median latency across 80+ networks, 100% gas estimates, and <50ms simulation exec time. This reduces false positives from bad gas estimates and supports SLOs. (tenderly.co)
  • Simulations everywhere: single tx, bundles, and Simulation RPC (tenderly_simulateTransaction, tenderly_simulateBundle). We dry-run responses to Forta alerts before we act on-chain. (blog.tenderly.co)
  • Web3 Actions with built-in node access to automate incident playbooks—no extra key management, fewer secrets in code, and immediate on-chain mitigation. (docs.tenderly.co)
  • Virtual TestNets (mainnet-replica dev/stage) for rehearsing runbooks with state overrides and millisecond tx execution. Perfect for RTO drills and change-management evidence. (tenderly.co)

1. “Money Move” Runbooks (what auto-executes)

• High-risk detection (Forta) → Action (Tenderly):
  • A Forta alert for “unauthorized role change” on your admin or Safe multisig triggers a Tenderly Web3 Action. We simulate pause() or access revocation using tenderly_simulateBundle, then submit the real transaction if the sim is safe. Notifications route to PagerDuty Severity-1. (docs.tenderly.co)
• Sequencer-layer block (Forta Firewall):
  • On your rollup, Forta Firewall blocks a malicious bundle pre-inclusion and logs the decision to Forta Chain; a webhook fires to Splunk for evidence, with payload signature and replay protection. Your SOC 2 auditor gets immutable, vendor-independent evidence. (docs.forta.network)
• Gas- and latency-aware retry:
  • If a mitigation tx is borderline on gas, we use Tenderly’s Gas Profiler + simulations to right-size calldata and reduce revert risk before burning on-chain gas. This saves budget and keeps MTTR low during hot paths. (docs.tenderly.co)

1. SIEM Integration and Audit Trail

• Configure Forta/Tenderly alert webhooks to Splunk HEC behind an allow list; include HMAC/Bearer headers and store full payloads with runbook IDs and response hashes. This satisfies alert-delivery proof and ensures reprocessing if a downstream system fails. (help.splunk.com)
• Keep a “Control Evidence Register”: 

  • Event → Destination (channel + headers) → SIEM index → Playbook execution logs → Simulation artifacts (Tenderly links) → On-chain tx hash (mitigation). Auditors care about traceability; this makes your walkthrough trivial.

1. Migration away from legacy Sentinel glue

• Because Defender is in maintenance mode with a hard stop on 2026-07-01, rebuild any Forta-to-Defender Sentinels as:
  • Forta App subscriptions to webhooks,
  • Plus Tenderly Alerts + Web3 Actions, 

  • Or your own lightweight listener on Forta’s GraphQL API feeding your SIEM/queue. This removes risk of mid-year outages. (docs.openzeppelin.com)

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Forta vs. Tenderly: When to use which (Enterprise lens)

• Use Forta when:

  • You need network-level threat intelligence and alert composability (handleAlert) across EVM chains. (docs.forta.network)
  • You can leverage pre-inclusion controls (Firewall) for rollups or contract-gated attestations to prevent malicious flows before they’re mined—this is the only way to truly “shift left” on incident timelines. (docs.forta.network)
  • You want on-chain, encrypted logs (Forta Chain) as defensible audit evidence. (docs.forta.network)
  • You need simple, on-chain subscription billing your procurement can audit (Unlock Protocol, 250 FORT/month General Plan). (docs.forta.network)

• Use Tenderly when:

  • You need a high-performance RPC with integrated simulations and alerting to minimize false positives and speed mitigation. Claims: 99.99% uptime SLA, <100ms median latency, 80+ networks. (tenderly.co)
  • You require “simulate, then act” incident runbooks with serverless code (Web3 Actions) and safe dry-runs (tenderly_simulateTransaction / tenderly_simulateBundle). (blog.tenderly.co)
  • Your team needs structured debugging (Debugger, Gas Profiler) to cut MTTR during production incidents and quantify gas savings pre-deploy. (docs.tenderly.co)
  • You want Virtual TestNets to rehearse fixes against a live mainnet mirror without risking funds, and to generate change-control evidence for audits. (tenderly.co)

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Practical examples

Example A — Sequencer-layer prevention on an Enterprise rollup
Context: You operate an OP Stack or Orbit rollup hosting high-value flows.
What we ship:

• Enable Forta Firewall via your RaaS partner (Conduit, Gelato, QuickNode, Alchemy, Zeeve). Set a risk threshold informed by your acceptable false-positive budget. Expect decision times under ~80ms at the screen. (docs.forta.network)
• Configure an allow/flag/block policy: 

  • “Block” for known exploit patterns and sanctioned addresses; 

  • “Delay” for ambiguous high-risk to preserve censorship-resistance, with resubmission after a delay; 

  • “Allow” for low-risk. Evidence written to Forta Chain for audit. (docs.forta.network)
• Wire alerts to PagerDuty and Splunk; store the Forta Chain tx references for the screened/blocked set. This is the “SOC 2-friendly” audit trail.

Example B — Protocol-level auto-mitigation with Tenderly
Context: Your admin role gets compromised; you must pause immediately.

• Tenderly Alert monitors for RoleGranted(Role.ADMIN) to a non-allowlisted address. Destination: PagerDuty (sev-1), Webhook to SIEM, and Web3 Action. (docs.tenderly.co)
• Web3 Action: 

  • Pulls latest state, runs tenderly_simulateBundle for pause() + revokeRole() sequence; 

  • If success, sends eth_sendRawTransaction via provided Gateway context; if not, fallback to a Safe transaction requiring 2-of-3 signers. (docs.tenderly.co)
• Gas Profiler validates that the mitigation path won’t blow your block gas target during congestion. (docs.tenderly.co)

Example C — Migration of legacy Forta→Defender glue

• Replace Defender Sentinel forwarding with Forta App subscriptions to webhooks + Tenderly Alerts. Maintain identical routes: Slack for low/medium, PagerDuty for high severity. Defender’s deprecation means you avoid a 2026 crunch. (docs.forta.network)

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Emerging best practices (we implement by default)

• Pre-inclusion first: If you control L2/L3 infra, push security to the sequencer with AI screening. Keep “delay not drop” semantics for censorship resistance and log it on a neutral ledger (Forta Chain). (docs.forta.network)
• Simulate-before-you-ship: Run every mitigation through tenderly_simulateBundle; track pass/fail and diffs in SIEM to justify decisions to auditors. (docs.tenderly.co)
• Tighten webhook hygiene: Require allow lists on SIEM, signed headers, and idempotency. Store headers and payloads as evidence. (help.splunk.com)
• Educate on “simulation lookalikes”: Gate your RPCs, document official endpoints, and flag third-party “RPCs” to customer support to stop social-engineering loops that exploit simulation UX. (reddit.com)
• Rehearse runbooks on Virtual TestNets: Treat them as “staging mainnet mirrors” for RTO drills, with state overrides and public/private explorers for stakeholder sign-off. (tenderly.co)

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What it costs (and how to defend it)

• Forta General Plan: 250 FORT/month unlocks 99%+ of non-premium bots with unlimited API usage; premium feeds priced per owner in USDC or FORT through Unlock Protocol. Easy to encode into OpEx with on-chain receipts. (docs.forta.network)
• Tenderly: priced by plan and consumption; procurement typically keys on published performance claims—99.99% uptime SLA, <100ms latency, 80+ networks, accurate gas and fast simulations—because they directly lower failure tickets and MTTR. 
 Use these claims to quantify ROI (fewer failed txs, fewer support escalations). (tenderly.co)
• Firewall for rollups: budget as “risk avoided” with visible metrics (>99% recall, minuscule FPR). Convert one prevented exploit into a cost center avoided; keep Forta Chain logs as proof in exec reviews. (forta.org)

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How 7Block Labs executes (and where we plug in)

• Architecture and implementation across solidity, monitoring agents, and rollup controls:
  • Custom Forta bots for protocol-specific invariants, plus Firewall policy definitions. 

  • Tenderly Alerts, Web3 Actions, and Simulation RPC wiring for auto-mitigation. 

  • SIEM integration with strict webhook controls and evidence capture.
• Deliverables include runbooks with SLAs, dashboards, and SOC 2 evidence packs mapped to your control framework.
• If you’re still pre-mainnet, we fold this into a build track: 

  • Smart contracts and runbook-ready code paths via our smart contract development and web3 development services. 

  • Security hardening with our security audit services. 

  • End-to-end app plumbing with our dApp development and blockchain integration. 

  • DeFi-specific stacks via our DeFi development services and DEX development.

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Proof (GTM-relevant metrics you can quote internally)

• Pre-inclusion screening: Forta Firewall integrates with RaaS providers (Conduit, Gelato, etc.) to filter high-risk transactions before they reach the sequencer—with published performance of >99% recall and <0.0002% false positives; decisions typically complete sub-~60–80ms. Data is written to Forta Chain (Arbitrum Orbit L3) for encrypted audit trails. (docs.forta.network)
• Network intelligence and subscriptions: Forta provides GraphQL/API or push subscriptions (email/Slack/Telegram/Discord/webhooks), with the General Plan priced at 250 FORT/month for broad coverage; premium feeds priced individually; payments via Unlock Protocol. Unlimited API calls per plan. (docs.forta.network)
• Developer observability: Tenderly Node RPC advertises 99.99% uptime, <100ms median latency across 80+ networks, <50ms simulation execution, and accurate gas estimation—directly tied to lower incident rates and faster MTTD/MTTR. (tenderly.co)
• Simulation-first response: Use tenderly_simulateTransaction and tenderly_simulateBundle to formalize “simulate-before-send” across all mitigations, reducing reverted hotfixes and gas waste. (blog.tenderly.co)
• Migration reality: OpenZeppelin Defender is in maintenance mode; new sign-ups disabled since 2025-06-30 and shutdown scheduled for 2026-07-01—plan a controlled migration rather than a scramble. (docs.openzeppelin.com)

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Bottom line

• Forta prevents what Tenderly helps you observe, simulate, and fix fast. Use both deliberately: Firewall at the edge (or contract gate) for prevention and evidence; Tenderly inside your DevSecOps loop for monitoring, alerting, gas-aware simulations, and automated incident response. 

• This design satisfies SOC 2 evidence, gives procurement clean SLAs, and—most importantly—turns “we saw it after it happened” into “we blocked it and have the receipts.”

7Block Labs can implement this exact blueprint in your environment, migrate away from brittle glue, and hand you the audit-ready monitoring stack your exec team expects.

Book a 90-Day Pilot Strategy Call

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Appendix: Quick technical references you’ll reuse in design docs

• Forta Network overview; bots and intel access. (docs.forta.network)
• Forta subscriptions and destinations (email/Slack/Telegram/Discord/webhook); GraphQL/API access. (docs.forta.network)
• Forta Bot SDK v2 (multi-chain), handleAlert composability; SDK handlers. (docs.forta.network)
• Forta Firewall: overview, RaaS integrations, risk score performance (FORTRESS), censorship-resistance via delay, Forta Chain (L3) for encrypted logs. (docs.forta.network)
• Tenderly Monitoring/Alerts, destinations (PagerDuty, webhooks), Web3 Actions with built-in node access. (tenderly.co)
• Tenderly Node RPC performance claims; simulations built into RPC; Simulation RPC docs (tenderly_simulateTransaction, tenderly_simulateBundle). (tenderly.co)
• Tenderly Virtual TestNets (mainnet replicas, state sync, explorer). (tenderly.co)

Related 7Block Labs capabilities

• custom blockchain development services
• cross-chain solutions development
• asset tokenization
• asset management platform development