Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/nguyenthienthanh/aura-frognpx agentmods add skills/nguyenthienthanh/aura-frog/api-designerWrote 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/nguyenthienthanh/aura-frog/api-designer)<a href="https://agentmods.dev/skills/nguyenthienthanh/aura-frog/api-designer"><img src="https://agentmods.dev/badge/skills/nguyenthienthanh/aura-frog/api-designer.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 5.1 | $0.00068 | $0.00817 |
| Opus 5 | $0.00034 | $0.00409 |
| Sonnet 5 | $0.00014 | $0.00163 |
| Haiku 4.5 | $0.00007 | $0.00082 |
Grade A, and why
api-designer 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 6d 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 — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AI-consumed reference. Optimized for Claude to read during execution. Human-readable explanation: see docs/architecture/HIERARCHICAL_PLANNING.md or docs/getting-started/ depending on topic.
Skill: API Designer
Design consistent, RESTful APIs with versioning, documentation, and error handling.
RESTful Conventions
| Method | Endpoint | Purpose | Response |
|---|---|---|---|
| GET | /users | List | 200 + array |
| GET | /users/:id | Get one | 200 / 404 |
| POST | /users | Create | 201 + created |
| PUT | /users/:id | Replace | 200 / 404 |
| PATCH | /users/:id | Update | 200 / 404 |
| DELETE | /users/:id | Delete | 204 / 404 |
Nested: GET /users/:userId/orders
Naming
- Resources: plural nouns (
/users,/orders) - Query params: snake_case (
page_size) - Request/Response bodies: camelCase
Versioning: URL path /api/v1/... (recommended).
Response Format
Success: { "data": {...}, "meta": {...} }
List: Add meta: { page, pageSize, total, totalPages }
Error: { "error": { "code": "VALIDATION_ERROR", "message": "...", "fields": {...} } }
Status Codes
| Code | When |
|---|---|
| 200 | Successful GET/PUT/PATCH |
| 201 | Successful POST |
| 204 | Successful DELETE |
| 400/422 | Invalid input / validation |
| 401/403 | No auth / no permission |
| 404/409 | Not found / conflict |
| 429 | Rate limited |
| 500 | Unexpected error |
Pagination
Offset: ?page=2&page_size=20 (simple, slow on large sets)
Cursor: ?cursor=abc&limit=20 (consistent, fast, no page jump)
Filtering & Sorting
GET /users?status=active&sort=created_at:desc&q=john&page=1&page_size=20
Design Workflow
- Define resources and relationships → 2. Choose versioning strategy → 3. Define endpoints with RESTful naming → 4. Specify response/error schemas → 5. Add pagination, filtering, sorting → 6. Document with OpenAPI → 7. Add rate limiting headers
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.
- 6d ago First seen · 105 lines · 68 tokens per session scan A b973b278e786
api-designer is a skill published in the GitHub repository nguyenthienthanh/aura-frog (24 stars, last pushed 2d ago), licensed MIT. It adds 68 tokens to every session and 817 once invoked, about $0.0003 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 2026-08-30.
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