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 roedyrustam/vibes-plug --skill api-design-expertgit clone --depth 1 https://github.com/roedyrustam/vibes-plugWrote 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/roedyrustam/vibes-plug/api-design-expert)<a href="https://agentmods.dev/skills/roedyrustam/vibes-plug/api-design-expert"><img src="https://agentmods.dev/badge/skills/roedyrustam/vibes-plug/api-design-expert/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/roedyrustam/vibes-plug/api-design-expert"><img src="https://agentmods.dev/badge/skills/roedyrustam/vibes-plug/api-design-expert.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 86 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 | $0.00082 | $0.03710 |
| Opus 5.5 | $0.00033 | $0.01484 |
| Sonnet 5.5 | $0.00016 | $0.00742 |
| Haiku 4.5 | $0.00008 | $0.00371 |
Grade A, and why
api-design-expert 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 2d 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 — 419 lines — stays where its author put it; the contents beside it link to each section on GitHub.
API Design Expert
English
Orchestration & Integration
- Upstream Ideation & Specs:
brainstorming,prd-architect,spec-driven-development-expert - Downstream Implementations:
js-backend-expert,python-programming-expert,go-programming-expert,rust-programming-expert - Contract & Gateway Tooling:
openapi-swagger-codegen-expert,api-gateway-proxy-expert,autonomous-api-drift-healer,graphql-apollo-expert - Security & Quality:
rate-limit-abuse-prevention,autonomous-red-teamer,e2e-testing-expert,anti-slop - Lifecycle & Governance:
zero-to-prod-orchestrator,session-memory-manager
Description
Expert guide for designing, documenting, and evolving production-grade APIs. Covers REST resource modeling and HTTP semantics, GraphQL schema design, gRPC with protobuf, and tRPC for end-to-end type-safe APIs in TypeScript monorepos. Includes OpenAPI 3.1 documentation, API versioning strategies, rate limiting, idempotency, and contract-first development workflows.
Trigger Conditions
- Designing a new API from scratch (REST, GraphQL, gRPC, or tRPC).
- Evolving an existing API without breaking clients.
- Documenting APIs with OpenAPI/Swagger.
- Implementing rate limiting, throttling, or idempotency.
- Choosing between REST, GraphQL, gRPC, and tRPC.
- Designing webhook systems.
- Implementing API authentication (API keys, JWT, OAuth2).
API Protocol Selection Guide
| Criteria | REST | GraphQL | gRPC | tRPC |
|---|---|---|---|---|
| Type Safety | Manual (OpenAPI) | Schema-enforced | Protobuf | End-to-end TS |
| Performance | Good | Good | Excellent (HTTP/2) | Good |
| Browser Support | Native | Native | Needs proxy | TS/JS only |
| Streaming | SSE / WebSocket | Subscriptions | Native bi-directional | SSE |
| Best For | Public APIs, mobile | Complex data graphs | Microservice-to-service | Next.js full-stack |
| Tooling | Universal | Rich ecosystem | Strong (Go, Java) | Next.js / Expo |
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.
- 2d ago Changed · +11 lines e51c92717567
- 3d ago Changed · +1 lines 7a1f2dbc9957
- 6d ago Changed · +89 lines b77d9b3c92c3
- 15d ago Changed 764631c8ddd6
- 20d ago Changed f9abc368360c
- 21d ago Changed 1faee8f87801
- 23d ago Changed · -6 lines · +71 tokens per session e4118c36d15f
- 25d ago Changed · +6 lines · -71 tokens per session da67afceb26b
- 1mo ago Changed 1bdb0688cb09
- 1mo ago First seen · 318 lines · 82 tokens per session scan A b63297c76bf9
api-design-expert is a skill published in the GitHub repository roedyrustam/vibes-plug (113 stars, last pushed today), licensed MIT. It adds 82 tokens to every session and 3,710 once invoked, about $0.0003 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 2026-08-30.
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