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 seb1n/awesome-ai-agent-skills --skill api-designgit clone --depth 1 https://github.com/seb1n/awesome-ai-agent-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/seb1n/awesome-ai-agent-skills/api-design)<a href="https://agentmods.dev/skills/seb1n/awesome-ai-agent-skills/api-design"><img src="https://agentmods.dev/badge/skills/seb1n/awesome-ai-agent-skills/api-design/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/seb1n/awesome-ai-agent-skills/api-design"><img src="https://agentmods.dev/badge/skills/seb1n/awesome-ai-agent-skills/api-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, 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 51 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.
- medium Data Exfiltration · line 209 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 | $0.00042 | $0.02137 |
| Opus 5.5 | $0.00017 | $0.00855 |
| Sonnet 5.5 | $0.00008 | $0.00427 |
| Haiku 4.5 | $0.00004 | $0.00214 |
Grade A, and why
api-design 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.
- **Testing:** Postman, Insomnia, REST Client (VS Code), curl Copies of this mod
1 near-identical copy found in the catalogue:
- api-design — 97% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 244 lines — stays where its author put it; the contents beside it link to each section on GitHub.
API Design
This skill enables an AI agent to design production-quality RESTful APIs. The agent models resources, defines endpoints with correct HTTP method semantics, selects appropriate status codes, implements pagination and versioning strategies, and produces OpenAPI documentation. The output follows REST constraints including statelessness, uniform interface, and resource-based URIs.
Workflow
-
Identify resources and relationships: Analyze the application domain to extract nouns as resources (e.g., users, tasks, comments). Map relationships between resources—one-to-many, many-to-many—and determine whether sub-resources or independent collections are appropriate. Avoid verb-based endpoints; resources should represent entities, not actions.
-
Define endpoints and HTTP methods: For each resource, define CRUD endpoints using the correct HTTP methods. Use GET for retrieval (safe, idempotent), POST for creation (not idempotent), PUT for full replacement (idempotent), PATCH for partial updates (idempotent), and DELETE for removal (idempotent). Nest sub-resources under their parent when the relationship is strong (e.g.,
/tasks/{id}/comments). -
Design request and response schemas: Define JSON request bodies, response payloads, and query parameters for each endpoint. Include field names in snake_case or camelCase consistently. Specify required vs. optional fields, data types, and validation constraints. Design a consistent error response envelope used across all endpoints.
-
Implement pagination, filtering, and sorting: For list endpoints, add cursor-based or offset pagination with
limitandoffset(orcursor) query parameters. Support filtering via query parameters (e.g.,?status=active) and sorting withsortandorderparameters. Return pagination metadata in the response body including total count, next/previous links. -
Define versioning and content negotiation: Choose a versioning strategy—URI path (
/v1/tasks), query parameter (?version=1), or Accept header (Accept: application/vnd.api.v1+json). URI path versioning is simplest and most common. Ensure backward compatibility within a version and document deprecation timelines.
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 First seen · 244 lines · 42 tokens per session scan A 931d48f3e6f5
api-design is a skill published in the GitHub repository seb1n/awesome-ai-agent-skills (229 stars, last pushed 2mo ago), licensed MIT. It adds 42 tokens to every session and 2,137 once invoked, about $0.0002 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.
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api-doc-generator
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api-contract
A guide for defining and reviewing an API contract: the agreed shape of requests, responses, authentication, errors, and compatibility rules between services. It can also guide OpenAPI checks and contract testing, which verifies that systems follow those agreements.
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telnyx-verify-curl
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