Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add rules/joaovicdev/nemesis/securitygit clone --depth 1 https://github.com/joaovicdev/nemesisWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00512 | $0.00512 |
| Opus 5 | $0.00256 | $0.00256 |
| Sonnet 5 | $0.00102 | $0.00102 |
| Haiku 4.5 | $0.00051 | $0.00051 |
Grade A, and why
security scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 57 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Security Rules
Sensitive Data Handling
- NEVER log target IPs, hostnames, credentials, CVE payloads, or finding details
at
DEBUGlevel or above in plain text. - NEVER include raw tool output in exception messages or tracebacks.
- All findings stored in SQLite are local-only — never transmitted to external services unless the user has explicitly configured and consented to an external LLM provider.
- Ollama runs locally — this is the default and preferred mode. External provider support (when added) must be opt-in with explicit acknowledgment from the user.
Scope Validation
- Before any tool execution, the target MUST be validated against the project scope:
- IP addresses must fall within the configured CIDR ranges.
- Domains must match or be subdomains of the configured targets.
- Out-of-scope targets MUST be rejected with a clear error — never silently skipped.
- Scope validation lives in
core/project.pyand is the single source of truth.
Tool Output Trust
- All output from external tools (nmap, nikto, gobuster, etc.) is UNTRUSTED until processed by the Analyst agent.
- Never interpolate raw tool output directly into shell commands (no shell injection).
- Always use
subprocesswithshell=Falseand explicit argument lists. - Sanitize any user-provided input before it is passed to subprocess arguments.
Destructive Action Guardrails
- Tools tagged
destructive=Truerequire explicit user confirmation (see architecture rules). - The following actions are ALWAYS considered destructive regardless of tool tag:
- Any exploit execution
- Brute-force / credential stuffing
- File uploads to target systems
- Commands that modify target system state
- Any action that could cause service unavailability (DoS-like behavior)
- Destructive action confirmations MUST be logged with:
- Timestamp
- Action description
- User confirmation ("yes" response)
- Session ID
Ethical Guardrails
- NEMESIS is designed for authorized penetration testing only.
- The project scope acts as the technical enforcement of authorization boundaries.
- Never add features that bypass scope validation or skip confirmation gates.
- The disclaimer in README.md and the first-run message are not optional — they must always be present and visible.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 57 lines · 512 tokens per session scan A e513c64c7d85
security is a cursor rule published in the GitHub repository joaovicdev/nemesis (4 stars, last pushed 4mo ago), licensed MIT. It adds 512 tokens to every session, about $0.0026 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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