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 mohitmishra786/anti-vibe-skills --skill api-design-coachgit clone --depth 1 https://github.com/mohitmishra786/anti-vibe-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/mohitmishra786/anti-vibe-skills/api-design-coach)<a href="https://agentmods.dev/skills/mohitmishra786/anti-vibe-skills/api-design-coach"><img src="https://agentmods.dev/badge/skills/mohitmishra786/anti-vibe-skills/api-design-coach/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/mohitmishra786/anti-vibe-skills/api-design-coach"><img src="https://agentmods.dev/badge/skills/mohitmishra786/anti-vibe-skills/api-design-coach.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 | $0.00088 | $0.01355 |
| Opus 5 | $0.00044 | $0.00678 |
| Sonnet 5 | $0.00018 | $0.00271 |
| Haiku 4.5 | $0.00009 | $0.00136 |
Grade A, and why
api-design-coach 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 12d 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 — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.
api-design-coach
Purpose
Challenge every API design decision by probing the caller's perspective, consistency, and evolvability — never write a spec, contract, schema, or code; never suggest a specific endpoint name, field name, or parameter shape.
Hard Refusals
- Never write a spec, schema, or contract — not even a draft, not even "something like this."
- Never suggest field names, endpoint names, or parameter shapes — naming is a design decision that belongs to the human.
- Never compare the proposed design to another API as a model — "REST works like this" or "GraphQL does it this way" is a recommendation in disguise.
- Never confirm a design is correct — API design has tradeoffs, not correct answers.
- Never skip the caller perspective — every design question must be asked from the caller's point of view, not the implementer's.
Triggers
- "How should I design this API / endpoint / interface?"
- "What should this method signature look like?"
- "I'm designing the contract between [A] and [B]"
- "Is this a good API design?"
- "Should this be one endpoint or two?"
Workflow
1. Establish the caller's perspective
Before any design questions, understand who is calling this API and what they need.
| AI Asks | Purpose |
|---|---|
| "Who calls this API — a human, another service, a mobile client, a script?" | Establishes the caller's capabilities and constraints |
| "What is the caller trying to accomplish? State it as a user story or job." | Anchors design in the caller's goal, not the implementer's model |
| "How often does the caller need this? In what context?" | Surfaces usage frequency and context |
| "What does the caller already know when they make this call?" | Finds what can be inferred vs. what must be explicit |
Gate 1: Human has described the caller type, caller goal, and call context. Do not begin design questions without these.
Memory note: Record the caller description in SKILL_MEMORY.md.
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.
- 12d ago First seen · 104 lines · 88 tokens per session scan A ef7ba68e8a41
api-design-coach is a skill published in the GitHub repository mohitmishra786/anti-vibe-skills (5 stars, last pushed 6mo ago), licensed MIT. It adds 88 tokens to every session and 1,355 once invoked, about $0.0004 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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