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 jonathan-vella/apex-accelerator --skill apex-vendor-promptinggit clone --depth 1 https://github.com/jonathan-vella/apex-acceleratorWrote 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/jonathan-vella/apex-accelerator/apex-vendor-prompting)<a href="https://agentmods.dev/skills/jonathan-vella/apex-accelerator/apex-vendor-prompting"><img src="https://agentmods.dev/badge/skills/jonathan-vella/apex-accelerator/apex-vendor-prompting/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/jonathan-vella/apex-accelerator/apex-vendor-prompting"><img src="https://agentmods.dev/badge/skills/jonathan-vella/apex-accelerator/apex-vendor-prompting.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00095 | $0.02596 |
| Opus 5.5 | $0.00038 | $0.01038 |
| Sonnet 5.5 | $0.00019 | $0.00519 |
| Haiku 4.5 | $0.00010 | $0.00260 |
Grade A, and why
apex-vendor-prompting 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 16d 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 — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Vendor Prompting Best Practices
Manual-only: use /apex-vendor-prompting explicitly for this audit workflow.
Do not load this skill automatically or read its body to bypass the invocation flag.
The thin authoring instructions and required vendor validators remain mandatory without this skill.
Audit-grade reference for the prompting patterns published by Anthropic
(Claude Opus 5.5, Sonnet 5.5) and OpenAI (GPT-6, GPT-5.6), plus explicitly identified APEX conventions. Used to author and audit
.agent.md and .prompt.md files in this repository.
The machine-readable source of truth is
rules.json — every rule has an ID, source citation,
severity, applies-to, and validator-check binding. The skill prose, the
thin enforcement instruction
vendor-prompting.instructions.md,
and validate-agents.mjs all reference rule IDs from that file.
When to Use This Skill
- Authoring a new
.agent.mdor.prompt.mdand wanting the right vendor patterns up front. - Auditing an existing agent against vendor best practices (the audit procedure is in audit-procedure.md).
- Investigating a finding from
npm run lint:vendor-prompting— every finding includes aruleIdthat maps to a rule in rules.json and back to a reference here. - Choosing the right model family for a new agent (decision rules in family-support.md).
Do NOT load this skill for routine edits where the format is
already known. The thin instruction
vendor-prompting.instructions.md
auto-loads on *.agent.md / *.prompt.md edits and carries the
hard-rule shortlist.
Decision Tree
I am editing or reviewing a *.agent.md / *.prompt.md ...
├── Which model is in the frontmatter?
│ ├── Claude Opus / Sonnet 5.5 → load references/claude-best-practices.md
│ ├── GPT-6 Sol / Luna (copilot) → load references/openai-prompting.md
│ ├── GPT-5.6 Terra (copilot) → load references/openai-prompting.md
│ ├── MAI-Code-1.1-Flash → reviewer-only; structural checks still run
│ └── Missing on prompt → resolve custom-agent or picker inheritance
│
├── Is this a .prompt.md (single string model:) or .agent.md (array)?
│ ├── prompt → load references/checklists.md "prompt" column
│ └── agent → load references/checklists.md "agent" column
│
└── Want the full audit procedure (5-15 min, produces written report)?
→ load references/audit-procedure.md and assets/audit-template.md
What ships with it
8 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.
- 16d ago Changed · +2 lines · +7 tokens per session 8517f8b52c04
- 20d ago Changed · +5 lines · +10 tokens per session 0b185b615d6a
- 22d ago Changed · +2 lines c7674de1e456
- 23d ago First seen · 174 lines · 78 tokens per session scan A 92ac99747083
apex-vendor-prompting is a skill published in the GitHub repository jonathan-vella/apex-accelerator (50 stars, last pushed yesterday), licensed MIT. It adds 95 tokens to every session and 2,596 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-09-23.
Other skills, from other repositories
gsap-scrolltrigger
Official GSAP skill for ScrollTrigger — scroll-linked animations, pinning, scrub, triggers. Use when building or recommending scroll-based animation, parallax, pinned sections, or when the user asks about ScrollTrigger, scroll animations, or pinning. Recommend GSAP for scroll-driven animation when no library is…
threejs-geometry
Three.js geometry creation - built-in shapes, BufferGeometry, custom geometry, instancing. Use when creating 3D shapes, working with vertices, building custom meshes, or optimizing with instanced rendering.
seedance-2-5
Generate 4-30 second cinematic video with ByteDance Seedance 2.5 through fal.ai, Volcengine Ark, Runway, or ComfyUI Partner Nodes. Use for long single generations, synchronized audio, and large multimodal reference sets (up to 30 images, 10 videos, and 10 audio clips). Also covers the 2.5 prompt contract: section…
comfyui
Use when working with ComfyUI workflows in OpenMontage, including comfyuiimage/comfyuivideo/comfyuimusic, custom workflowjson/workflowpath inputs, outputnode selection, missing model setup, LoRAs, low-VRAM workflow choices, and community workflow imports.
lyria
Generate and validate music with Google Lyria 3 through the Gemini Interactions API. Use before calling OpenMontage googlemusic, designing Lyria 3 Clip or Pro prompts, using image-to-music or custom lyrics, choosing between Lyria 3 and Lyria RealTime, diagnosing Google music-generation failures, or preparing…
dashscope
DashScope (Alibaba Cloud Bailian / 阿里云百炼) integration — image generation (qwen-image-2.0-pro), text-to-speech (qwen3-tts-flash), and ASR with word-level timestamps (qwen3-asr-flash-filetrans). Use when generating images via Qwen-Image, narrating via Qwen-TTS, or transcribing with word-level timestamps via Qwen-ASR.