What Firewall does

Firewall is a San Francisco-based, pre-revenue infrastructure startup founded in January 2023 by Devan and Sam to solve smart contract exploits at the blockchain execution layer. The company's core thesis is that blockchains validate cryptographic validity and fee payment but ignore transaction intent — leaving DeFi users exposed to irreversible theft — and that the most effective intervention point is the sequencer that constructs blocks, not pre-deployment audits or external monitoring.

Its core product is the Safe Sequencer, a custom blockchain execution client built around the Rust-based reth client and an OP-Stack fork, with A.I. models and pattern recognition algorithms embedded directly into the EVM. The sequencer inspects every proposed state change and rejects transactions classified as exploitative before block inclusion, while allowing normal activity (swaps, deposits, LP positions, flash loans) to pass through. Detection algorithms in production use include ReentrancyGuard and Charmander, and the system is anchored to Ethereum to preserve user rights non-custodially. Surrounding tooling includes the Firewall Explorer (a public testnet explorer showing passed/blocked transactions) and a Protect Dashboard for app operators.

Go-to-market is B2B/infrastructure: rollups and L2 chains integrate the Safe Sequencer into their block-production infrastructure to differentiate their blockspace, while DeFi protocols deploy contracts protected via the Protect Dashboard. End-user adoption is cultivated through a community-led motion on Discord, Twitter/X (@UseFirewall), and Farcaster, supplemented by proof-of-tech demonstrations (notably the October 2025 recreation of the $56M KyberSwap exploit blocked on Firewall testnet but successful on Base testnet) and educational blog content. Pricing is not publicly disclosed. The company has raised $3.7M (2024-03-06) led by Breyer Capital and Hack VC with Finality Capital Partners and North Island Ventures, and operated a 12-week v1 testnet processing ~5.14M transactions before shutting it down on November 21, 2025 to prepare for v2.

Name

Firewall

Website

https://usefirewall.com

Company type

Private

Founded year

2023

Operating status

Operating

Headcount range

11–50 employees

Short description

Firewall is building Safe Blockspace, an A.I.-embedded blockchain sequencer that filters smart contract exploits at block construction. It sells into rollups, L2 chains, and DeFi protocol operators to provide runtime transaction-intent validation anchored to Ethereum.

Ownership category

akta.pro rank

Product category

Blockchain Security Infrastructure

NAICS

Financial Transactions Processing, Reserve, and Clearinghouse Activities (522320), Financial Transactions Processing, Reserve, and Clearinghouse Activities (52232)

SIC

Security & Commodity Brokers, Dealers, Exchanges & Services (6200), Services-Computer Programming Services (7371)

akta.pro primary industry

Digital Asset Risk, Security & Audit Tooling (Smart Contract Audit, Threat Monitoring) (FSAGAMAJ)

akta.pro secondary industries

MEV / Block-Building, Proposer-Builder Separation (PBS) & Relays (FSADAKAG), Node Operations, RPC & Infrastructure Services (nodes, validators, RPC, relayers) (FSAPAAAF)

Keywords

• Blockchain security
• Smart contract protection
• Layer 2 infrastructure
• Execution layer security
• DeFi exploit prevention

Headquarters

HQ city

San Francisco

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Software

Cost components

Personnel, Technology or R&D, Marketing or Sales, Operations

Go-to-market motion2 records

Distribution channels1 record

Marketing channels7 records

Core offering

Firewall builds and sells the Safe Sequencer, an AI-instrumented blockchain execution client (built on the reth client) embedded directly in the EVM, which filters smart contract exploits at block construction before transactions are finalized. The product is delivered to rollups and L2 chains so they can offer "Safe Blockspace" — blockspace where theft is treated as an invalid state transition — without requiring user behavior changes or smart contract modifications. Supporting tools include the Firewall Explorer and Protect Dashboard for verifying filtered transactions and managing contract protections.

Product overview

Firewall is building Safe Blockspace — a paradigm shift in blockchain architecture where the chain itself programmatically protects users from theft. The core offering is the Safe Sequencer, a custom blockchain execution client built on the reth client with A.I. models embedded directly in the EVM to filter malicious transactions at block construction. Supporting tools include the Firewall Explorer (for verifying blocked exploits and transaction status) and the Protect Dashboard (for app operators to manage contract protection). Together, these products deliver a chain environment where exploit transactions are rejected before finalization, while legitimate DeFi activity is unaffected.

Differentiator

Problem solved

Functional benefit

Brands

• Safe Sequencer: A superfast, provably neutral processor instrumented with A.I. models to filter out smart contract exploits at block construction, before they impact users.

Products and services

• Safe Sequencer A custom blockchain execution client built on the reth (Rust) client and instrumented with AI models and pattern recognition algorithms embedded directly into the EVM. It filters out smart contract exploits at block construction before transactions are finalized, adding a third validation criterion (transaction does not steal user assets) on top of cryptographic validity and fee payment. The Safe Sequencer is the primary implementation of Safe Blockspace and is licensed to rollups and L2 chains to protect their applications and differentiate their blockspace.
• Safe Blockspace An architectural paradigm for rollups in which blockspace is designed to be inherently safe — treating theft as an invalid action rather than accepting it as a valid state transition. Safe Blockspace embeds AI-driven filtering into the execution layer of a blockchain to eliminate smart-contract exploits, with the Safe Sequencer as its first component.
• Firewall Explorer A blockchain explorer for Firewall's testnet that displays blocks, transactions, smart contract deployments, detection algorithm status (Passed/Blocked), and call traces. It enables users and developers to verify that exploit transactions are blocked while legitimate transactions pass through.
• Protect Dashboard Dashboard interface for app operators to onboard their deployed smart contracts, view detection algorithms applied to them, and monitor contract protection status on Safe Blockspace.

Quantifiable outcome

• KyberSwap exploit ($56M) successfully blocked on Firewall testnet while succeeding on Base testnet
• +1 more outcomes

Segments3 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability4 records

Feature5 records

Scale indicators4 records

Recent moves5 records

Expansion highlights4 records

Direct peers

• Blockaid: Blockaid provides real-time Web3 security and scam detection for transactions, dApps, and wallets. Closest direct competitor: like Firewall, Blockaid screens transactions for malicious intent before users sign, pursuing the same runtime detection vision though via off-chain simulation layers rather than embedded-in-EVM AI.
• Blowfish: Blowfish offers real-time transaction screening and phishing/malicious-transaction detection for Web3 wallets and applications. Comparable to Firewall in protecting end users from on-chain exploits, but does so via API-driven simulation rather than at block construction inside the execution client.
• Forta Network: Forta is a decentralized monitoring network that provides real-time detection of exploits, scams, and security incidents across multiple chains. Directly comparable to Firewall's monitoring/incident-response thesis; both compete to be the security and observability layer for Web3 activity.
• Certora: Certora provides formal verification tools for smart contracts, used to mathematically prove correctness of code. Directly comparable on the broader 'verify smart contracts are safe' mission, but Certora's approach is static/formal vs Firewall's runtime intent analysis.
• Hacken: Hacken offers smart contract auditing, bug bounties, and blockchain security services across multiple chains. Comparable to Firewall as a Web3 security vendor aiming to prevent exploits and protect DeFi users, though primarily auditing-focused rather than embedded-runtime.
• PeckShield: PeckShield is a blockchain security firm providing smart contract auditing, on-chain monitoring, and incident response. Comparable to Firewall on multi-chain smart contract exploit prevention and monitoring, with overlap in the DeFi-protect-segment thesis.

Broad incumbents

• OpenZeppelin: OpenZeppelin is a leading smart contract security and developer platform providing audits, Defender for operations and monitoring, and reusable contract libraries. A broader incumbent in Web3 security with overlapping concerns around runtime protection that Firewall addresses at the execution layer.
• Chainalysis: Chainalysis is a major blockchain analytics and compliance platform used by government and financial institutions. While adjacent rather than directly competing, Chainalysis represents the established leader in on-chain threat intelligence and compliance tooling that overlaps with Firewall's security category.
• Quantstamp: Quantstamp provides smart contract auditing, formal verification, and blockchain security services. Competes with Firewall on smart contract exploit prevention but relies on pre-deployment auditing where Firewall's value proposition (runtime execution-layer protection) is differentiated.
• ConsenSys Diligence: ConsenSys Diligence is ConsenSys's smart contract auditing and security services arm. A broader incumbent in Web3 security, comparable to Firewall on the audit/verification mission but operates at the pre-deployment layer rather than runtime execution layer.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/usefirewall
• GitHubgithub.com/Firewall-eng

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Funding overview

Funding rounds1 record

Investors4 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Firewall