secure-by-design

secure-by-design is a skill for Claude Code from RedHatProductSecurity/prodsec-skills. It costs 43 tokens per session (662 once invoked), scanned A, original, Apache-2.0.

A guide to Secure by Design, Secure by Default, and Secure in Deployment principles for applications and services.

In plain words
What is it for?
Use it to review default settings, installation and update processes, secret generation, least-privilege configurations, fail-closed behavior, and security baselines.
Why use it?
It helps prevent unsafe setup choices, unnecessary permissions, and failures that accidentally grant access.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the prodsec-skills-ge-core plugin — 12 skills shipped together

Good fit Use it to review default settings, installation and update processes, secret generation, least-privilege configurations, fail-closed behavior, and security baselines.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/redhatproductsecurity/prodsec-skills/secure-by-design
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.

Any agent
npx skills add RedHatProductSecurity/prodsec-skills --skill secure-by-design
Clone the repo
git clone --depth 1 https://github.com/RedHatProductSecurity/prodsec-skills

Made for: Claude Code.

Or install prodsec-skills-ge-core, the plugin that ships this one along with the rest of its 12 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for secure-by-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/redhatproductsecurity/prodsec-skills/secure-by-design/github.svg)](https://agentmods.dev/skills/redhatproductsecurity/prodsec-skills/secure-by-design)
Your own site
<a href="https://agentmods.dev/skills/redhatproductsecurity/prodsec-skills/secure-by-design"><img src="https://agentmods.dev/badge/skills/redhatproductsecurity/prodsec-skills/secure-by-design/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for secure-by-design

Your own site · 80×15
<a href="https://agentmods.dev/skills/redhatproductsecurity/prodsec-skills/secure-by-design"><img src="https://agentmods.dev/badge/skills/redhatproductsecurity/prodsec-skills/secure-by-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 662 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00043 $0.00662
Opus 5 $0.00022 $0.00331
Sonnet 5 $0.00009 $0.00132
Haiku 4.5 $0.00004 $0.00066

Measured 10d ago against content hash 3ff49538c18e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

secure-by-design 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 10d 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.

ge-core/secure-by-design/SKILL.md · 73 lines

How it starts

The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Secure by Design, by Default, in Deployment (SD3)

Principle: The default settings of a system or application are configured with strong security measures in place. Systems should be configured in a least-privilege model so that no unnecessary services, daemons, or accounts are enabled.

Secure Default Configurations

  • Ship products with secure defaults that protect users without requiring manual hardening
  • Generate unique keys and secrets during first run or installation, not at build time
  • Encourage users to review and customize settings, but ensure the uncustomized state is safe
  • Minimizes risk from users or administrators who overlook or delay security configuration

Fail Secure

  • Design services to fail closed: when they fail, they deny access rather than granting it
  • A security service that cannot be reached must result in a denied request, not an open door
  • Apply this to authentication, authorization, input validation, and configuration loading

Secure Baselines

  • Create server and application security baselines as reference configurations
  • Deploy new systems from these baselines to ensure consistency
  • Systems adhering to baselines are less vulnerable and require less ongoing maintenance

Encryption and Authentication by Default

  • Enable encryption (TLS) and authentication by default, not as opt-in features
  • Use HTTPS as the default communication protocol
  • Protect data in transit and at rest as a baseline, not an upgrade

No Hardcoded Credentials

  • Never use hard-coded secrets, default passwords, or static account credentials in code
  • Generate unique credentials at deployment time
  • Use secrets management systems (Vault, AWS Secrets Manager, etc.)

Default Deny Policies

  • Only explicitly allowed actions are permitted
  • No unnecessary services, daemons, or network ports are enabled
  • Default network policies deny all traffic; allow rules are added explicitly

Code Integrity and Updates

  • Use digital signatures and cryptographic hashes to verify the integrity and authenticity of software updates
  • Implement automated update mechanisms to reduce the window of vulnerability
  • Test patches thoroughly before deployment
  • Secure the update infrastructure itself with access controls and monitoring

Read the full file on GitHub · 73 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. 10d ago First seen · 73 lines · 43 tokens per session scan A 3ff49538c18e

Subscribe to this mod's changes

secure-by-design is a skill published in the GitHub repository RedHatProductSecurity/prodsec-skills (52 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 43 tokens to every session and 662 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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