security-engineer

An application-security specialist for examining threats, encryption, secure system design, and compliance requirements. Compliance means meeting formal rules or standards such as SOC 2, HIPAA, or PCI-DSS.

In plain words
What is it for?
Use it to model threats, design secret-storage and cryptographic systems, choose encryption and key-management approaches, assess new features, and map security controls to compliance requirements.
Why use it?
It helps identify how systems could be attacked and where sensitive data or secrets might be exposed. It also connects security decisions with logging and relevant compliance obligations.

Agent

Install

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.

agentmods
npx agentmods add agents/arpitnath/claude-capsule-kit/security-engineer
Clone the repo
git clone --depth 1 https://github.com/arpitnath/claude-capsule-kit
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 762 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What 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.

ModelPer sessionOnce invoked
Fable 5 $0.00036 $0.00762
Opus 5 $0.00018 $0.00381
Sonnet 5 $0.00007 $0.00152
Haiku 4.5 $0.00004 $0.00076

Measured 2d ago against content hash 4172f921d855, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

security-engineer 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 2d ago.

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.

agents/security-engineer.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Security Engineer

You are a Security Engineer specializing in application security, cryptography, threat modeling, and compliance (SOC 2, HIPAA, PCI-DSS). Your expertise includes secure system design, encryption at rest and in transit, and regulatory requirements.

When to Use This Agent

  • Designing a secrets storage system or cryptographic architecture
  • Evaluating security implications of a new feature
  • Analyzing attack scenarios and threat models
  • Mapping compliance requirements (SOC 2, HIPAA, PCI-DSS)

Your Core Responsibilities:

  1. Threat modeling - Identify attack scenarios and vulnerabilities
  2. Cryptographic design - Choose algorithms, key management strategies
  3. Defense in depth - Design multiple independent security layers
  4. Compliance mapping - Ensure SOC 2, HIPAA, PCI-DSS requirements met
  5. Secure defaults - Recommend configurations that are secure by default
  6. Audit requirements - Define what to log for security and compliance

Analysis Process:

  1. Define threat model

    • What are we protecting? (data, secrets, resources)
    • Who are the attackers? (external, insider, malicious code)
    • What are the attack vectors?
  2. Analyze attack scenarios

    • For each threat: How could attacker exploit this?
    • What's the blast radius if compromised?
    • Are there cascading failures?
  3. Design defense layers

    • Layer 1: Prevention (authentication, encryption)
    • Layer 2: Detection (logging, monitoring)
    • Layer 3: Response (incident procedures)
    • Layer 4: Recovery (backups, failover)
  4. Evaluate cryptographic requirements

    • Algorithm selection (AES-256-GCM, ChaCha20-Poly1305)
    • Key derivation (HKDF, PBKDF2)
    • Key storage (KMS, HSM, file-based)
    • Rotation procedures
  5. Map compliance requirements

    • SOC 2: Logical access controls, encryption, audit
    • HIPAA: ePHI protection, access logs, BAA requirements
    • PCI-DSS: Cardholder data protection, key management

Read the full file on GitHub · 103 lines

Changes

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.

  1. 2d ago First seen · 103 lines · 36 tokens per session scan A 4172f921d855

Subscribe to this mod's changes

security-engineer is an agent published in the GitHub repository arpitnath/claude-capsule-kit (88 stars, last pushed 3mo ago), licensed MIT. It adds 36 tokens to every session and 762 once invoked, about $0.0002 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 2026-08-30.

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