Deepsec

Overview

Deepsec is an open-source security harness from Vercel Labs that takes a fundamentally different approach to vulnerability scanning. Instead of relying on static pattern matching or signature databases, Deepsec uses AI coding agents to perform tailored, context-aware investigation of your codebase. It runs on your own infrastructure so your source code never leaves your control, and it uses frontier models at maximum reasoning effort to surface the kind of subtle, logic-level vulnerabilities that traditional scanners miss.

Key Capabilities

At its core, Deepsec orchestrates AI agents to methodically analyze code paths, data flows, and architectural patterns for security weaknesses. It supports optional fanout to Vercel Sandboxes for remote execution, allowing scans to scale to over 1,000 concurrent sandboxes when scanning large codebases. The tool is configured to use the best available models at maximum thinking levels, which enables deep reasoning about complex vulnerability patterns but means scan costs can be significant for large projects.

Use Cases

Security teams use Deepsec for deep-dive audits of critical codebases where traditional static analysis tools fall short. It is particularly effective at finding logic vulnerabilities, authentication bypasses, and complex injection patterns that require understanding application context. Development teams integrate it into pre-release security reviews for high-risk changes.

Considerations

Deepsec is free and open-source but requires API keys for the underlying AI models. Scans use models at maximum reasoning effort, which can cost thousands of dollars for large codebases. The false positive rate is roughly 10-20%, so findings require human review. Scan times scale with codebase size and concurrency configuration.

Who It’s For

Deepsec is designed for security engineers, AppSec teams, and development teams responsible for securing large codebases. It is most valuable when traditional scanners are not catching the kinds of vulnerabilities your threat model demands, and when you need AI-powered reasoning about complex code paths.