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 skills add sd0xdev/sd0x-harness --skill feature-verifygit clone --depth 1 https://github.com/sd0xdev/sd0x-harnessWrote 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/sd0xdev/sd0x-harness/feature-verify)<a href="https://agentmods.dev/skills/sd0xdev/sd0x-harness/feature-verify"><img src="https://agentmods.dev/badge/skills/sd0xdev/sd0x-harness/feature-verify/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.
<a href="https://agentmods.dev/skills/sd0xdev/sd0x-harness/feature-verify"><img src="https://agentmods.dev/badge/skills/sd0xdev/sd0x-harness/feature-verify.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 149 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 5.1 | $0.00075 | $0.03385 |
| Opus 5.5 | $0.00030 | $0.01354 |
| Sonnet 5.5 | $0.00015 | $0.00677 |
| Haiku 4.5 | $0.00007 | $0.00338 |
Grade A, and why
feature-verify scanned grade A with 1 finding 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 1mo 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
> **Tool safety note**: `allowed-tools` includes `Bash` for curl/log queries. Read-only enforcement is behavioral — all commands MUST be reviewed against `references/safety-rules.md` before execution. Codex independently How it starts
The opening of the file, as written. The whole thing — 297 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Feature Verify — Runtime-First API Verification
Trigger
- Keywords: verify, investigate, diagnose, check if working, post-deploy, smoke test, validate
- User wants to confirm deployed feature behavior
- User provides environment access (API URL, log system, credentials)
When NOT to Use
| Need | Use Instead |
|---|---|
| Modify data or state | /feature-dev |
| Code quality review | /codex-review-fast |
| Generate unit tests | /codex-test-gen |
| Security audit | /codex-security |
| Run local tests | /verify |
| Review test coverage | /codex-test-review |
Core Principle
⚠️ ALL OPERATIONS MUST BE READ-ONLY ⚠️
Claude independent analysis → Codex third-perspective confirmation → Integrated verdict
Tool safety note:
allowed-toolsincludesBashfor curl/log queries. Read-only enforcement is behavioral — all commands MUST be reviewed againstreferences/safety-rules.mdbefore execution. Codex independently verifies compliance at P5.
Degradation Matrix
Auto-detect from references/environments.md configuration:
| Level | Available Resources | P3 API | P4 Observation | Confidence Cap |
|---|---|---|---|---|
| L4 | API + Log + Metrics | Full | Log + Metrics | High |
| L3 | API + Log | Full | Log only | High |
| L2-API | API only | Full | Response-only | Medium |
| L2-OBS | Log only (API unreachable) | Skip | Time-window scan | Medium |
| L1 | No runtime access | Skip P3/P4 | Code review only | Low |
Auto-detection logic (see references/environments.md § Degradation Detection):
| API Status | Log System | Metrics | Level |
|---|---|---|---|
| Reachable | Yes | Yes | L4 |
| Reachable | Yes | No | L3 |
| Reachable | No | — | L2-API |
| Unreachable | Yes | — | L2-OBS |
| Unreachable | No | — | L1 |
Fail-closed: If Endpoint Allowlist section is missing, skip P3 (cannot call unverified endpoints). At L1, skip P3 and P4. Provide code-review-based analysis only with Low confidence. At L2-OBS, skip P3 (API unreachable); execute P4 time-window scan and background service observation only.
What ships with it
4 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.
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.
- 1mo ago Changed · +8 lines 4395fa06ac70
- 1mo ago First seen · 289 lines · 75 tokens per session scan A 21d6be8696f7
feature-verify is a skill published in the GitHub repository sd0xdev/sd0x-harness (194 stars, last pushed 11d ago), licensed MIT. It adds 75 tokens to every session and 3,385 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
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Use when writing production code test-first: the RED-GREEN-REFACTOR cycle, false-RED detection, vertical slicing, scope escalation, test process discipline, and code generation patterns.
verify-qa
A conditional end-to-end quality-assurance workflow for changes to a user interface. End-to-end testing checks a feature through the whole user path, often in a real browser, and this workflow also includes performance and accessibility checks.
ui-validate
A collection of independent checks for validating web interfaces. It measures visual hierarchy and accessibility, checks motion rules, detects visual drift across screens, tests common viewport sizes, and captures evidence for specified test cases.
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ios-test
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swiftui-autotest-skill
AI-powered visual testing and accessibility setup for iOS/SwiftUI apps. Build, launch in Simulator, test with computer use, detect crashes, analyze memory leaks, and add accessibility identifiers — all from the terminal.