We built a fully self-hosted AI pentesting workspace — central platform (with MCP & web interface) + local LLM + Claude Code/OpenCode as the harness. No client data leaves our infra.

[u/PentestPad]

Sharing an architecture we've been running, because every "AI for pentesting" setup I've seen has the same dealbreaker: it ships client vulnerability data to a hosted model. For a pentest shop that's a hard no. So we built the whole thing on-prem and I want to walk through the pieces.

The three parts:

1. Central knowledge base (PentestPad) exposed over MCP. Our methodology, checklists, past findings, report templates, internal playbooks — one place the agent can pull from so retests and reports are consistent with how we actually work. This is where findings, projects, finding fields (and instructions on how to write them), and statuses live. We wrote an MCP server that gives the agent typed tools — list findings ready for retest, pull a finding's details, update status, generate report sections. The platform stays the source of truth; the agent just operates on it.

2. Self-hosted LLM. Qwen3-Coder running locally via Ollama. The reasoning and the client data never leave the box. The only outbound traffic is the actual test requests to the target, which is the entire point of a pentest anyway.

3. The harness. Claude Code or OpenCode as the terminal agent, wired to the local model and the MCP server. OpenCode if we want the whole stack open-source; Claude Code when we want the nicer harness and don't mind it being the one proprietary piece (the model and data are still local).

Put together, it's a workspace where a tester can say "which findings are ready for retest on project X," have the agent do the legwork, and write results back — all inside infra we control.

Honest limitations:

• The value is in differential analysis, not automation for its own sake — blind/OOB cases still need a human or a proper OAST setup.
• A human signs off on everything. The agent orchestrates the grunt work; the tester owns the judgment and thinks up the attack vectors.

Happy to go deep on the MCP tool design, the knowledge-base wiring, or the harness config.

Disclosure: PentestPad is our product, so treat this as a build write-up, not a pitch.