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 skills/photostructure/coding-skills/web-security-hardeningnpx skills add photostructure/coding-skills --skill web-security-hardeninggit clone --depth 1 https://github.com/photostructure/coding-skillsWrote 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.
[](https://agentmods.dev/skills/photostructure/coding-skills/web-security-hardening)<a href="https://agentmods.dev/skills/photostructure/coding-skills/web-security-hardening"><img src="https://agentmods.dev/badge/skills/photostructure/coding-skills/web-security-hardening.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00128 | $0.03054 |
| Opus 5 | $0.00064 | $0.01527 |
| Sonnet 5 | $0.00026 | $0.00611 |
| Haiku 4.5 | $0.00013 | $0.00305 |
Grade A, and why
web-security-hardening 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 5d 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.
How it starts
The opening of the file, as written. The whole thing — 278 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Web and Electron Security Hardening
Assess JavaScript/TypeScript web and Electron desktop applications against practical, evidence-based security baselines. Report applicable preventive-control gaps even when no exploit path is currently proven, while clearly distinguishing hardening advice from vulnerabilities.
Use OWASP ASVS 5.0.0 as the pinned requirements backbone. Use OWASP Cheat Sheets, current framework/library documentation, MDN, and NIST SP 800-63B-4 to explain and implement web/service controls. When Electron is present, also use Electron's current security checklist and official runtime, packaging, and platform documentation for the desktop boundary. See ATTRIBUTION.md.
For web-only work, call the result an ASVS-guided hardening review, not ASVS compliance or certification, unless every requirement at the selected level has been enumerated, assessed for applicability, and supported by the evidence ASVS requires. Electron reviews use the dual-baseline name defined below.
Boundary with vulnerability review
Keep this skill separate from web-security-review:
| This skill | web-security-review |
|---|---|
| Asks whether applicable controls meet a baseline | Asks whether an attacker can exploit the code |
| Reports evidence-backed best-practice gaps | Reports only proven vulnerabilities |
| Uses Met / Gap / Not applicable / Needs verification | Uses Critical / High / Medium / Low |
| Prioritizes Essential / Recommended / Optional | Prioritizes exploit impact |
Do not call a missing control a vulnerability or assign CVSS-style severity without a
concrete attack path. If the review uncovers a proven exploit, list it separately under
Escalate to vulnerability review and recommend the web-security-review skill; do
not mix it into hardening counts.
Core rules
- Applicability before compliance. Profile the application and select only controls that match its actual browser, API, identity, data, and deployment surfaces.
- Effective behavior over package presence.
helmet()installed, a schema library imported, or a proxy named in docs is not proof that the control applies to every relevant route in the shipped configuration. - Research beyond report scope when needed. Trace relevant callers, middleware, framework defaults, deployment config, and shared helpers; report only on the scope requested by the user. Do not load unrelated monorepo areas merely for completeness.
- Credit framework protections. Mark a control Met when a detected framework/version provides it effectively and no bypass disables it.
- No cargo-cult controls. Record Not applicable when a control has no relevant surface (for example CSP on a JSON-only API), with one-line reasoning.
- No generic “sanitize everything.” Validate syntax and business semantics at trust boundaries, encode for the output context, and sanitize only formats that intentionally accept active/rich content.
- No live attacks. Use static evidence and safe local tests only. Never probe shared, configured, or production services as part of a hardening review.
- No auto-apply. Propose changes; edit only when the user explicitly asks.
What ships with it
36 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- agents/openai.yaml 254 B
- ATTRIBUTION.md 3.0 KB
- LICENSE 749 B
- references/baseline-and-reporting.md 8.6 KB
- references/browser-and-http.md 9.7 KB
- references/deployment-and-operations.md 17 KB
- references/electron-controls.md 22 KB
- references/identity-sessions-and-secrets.md 15 KB
- references/input-output-and-files.md 13 KB
- references/javascript-frameworks.md 10 KB
- references/techniques/authentication.md 5.2 KB
- references/techniques/authorization.md 4.6 KB
- references/techniques/command-injection.md 3.5 KB
- references/techniques/cors.md 4.7 KB
- references/techniques/crypto-aead.md 4.9 KB
- references/techniques/csrf.md 4.7 KB
- references/techniques/deserialization.md 3.8 KB
- references/techniques/fail-closed.md 4.7 KB
- references/techniques/jwt.md 4.0 KB
- references/techniques/mass-assignment.md 4.1 KB
- references/techniques/misconfiguration.md 4.5 KB
- references/techniques/nosql-injection.md 4.5 KB
- references/techniques/open-redirect.md 4.3 KB
- references/techniques/path-traversal.md 4.0 KB
- references/techniques/prototype-pollution.md 3.7 KB
- references/techniques/rate-limiting-dos.md 4.9 KB
- references/techniques/redos.md 4.0 KB
- references/techniques/secrets-exposure.md 4.2 KB
- references/techniques/security-headers.md 4.3 KB
- references/techniques/sql-injection.md 4.0 KB
- references/techniques/ssrf.md 4.6 KB
- references/techniques/ssti.md 4.1 KB
- references/techniques/supply-chain-ci.md 4.7 KB
- references/techniques/tls.md 4.7 KB
- references/techniques/xss-sinks.md 4.1 KB
- references/techniques/xxe-parsers.md 4.6 KB
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.
- 5d ago First seen · 278 lines · 128 tokens per session scan A 4c801b4d4446
web-security-hardening is a skill published in the GitHub repository photostructure/coding-skills (3 stars, last pushed yesterday), licensed MIT. It adds 128 tokens to every session and 3,054 once invoked, about $0.0006 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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