Assail

Assail builds Ares, an agentic offensive AI platform for continuous penetration testing of the application layer: APIs (REST, GraphQL, gRPC, WebSocket), mobile apps, and web applications. Rather than scanning for known signatures, Ares deploys coordinated AI agents that plan engagements, chain multi step attacks, and prove impact through exploitation, mapping findings to MITRE ATT&CK with replayable records that include agent reasoning and live network traces.

The platform runs on proprietary models rather than wrapped frontier models: Dagger, a fourteen billion parameter offensive security model, followed in July 2026 by Sidewinder, a second generation redesign with twelve specialized agents working against a persistent knowledge graph of the target's attack surface and vision grounded browsing that drives a real browser through single page apps and authenticated identities. A co evolutionary training loop pits an Adversary Simulator against a Breacher to generate novel techniques without human curated data.

Assail was founded by Alissa Knight, a twenty six year offensive security veteran, is headquartered in Boston, and is backed by Venture Guides after a pre seed led by Squared Circle Ventures. Ares became generally available February 2026, with an open source Docker agent for behind the firewall deployment and managed or fully on premises options for sovereign and air gapped environments.