A guide for designing REST APIs, which are web interfaces that let software exchange data through standard URLs and requests. It covers URL structure, query parameters, API documentation, and response formats.

Use it when adding or reviewing REST endpoints, including their paths, filters, pagination, sorting, OpenAPI descriptions, and response wrappers.

It helps prevent inconsistent endpoint names, parameter handling, documentation, and success or error responses.

How themoment-team/datagsm-server configures Claude Code and Codex

Reuse

Borrowing it

Nothing to install: this file belongs to themoment-team/datagsm-server. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/themoment-team/datagsm-server/master/.agents/skills/api-design/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/themoment-team/datagsm-server

Made for: Claude Code, Codex.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/themoment-team/datagsm-server/api-design/github.svg)](https://agentmods.dev/skills/themoment-team/datagsm-server/api-design)

Your own site

<a href="https://agentmods.dev/skills/themoment-team/datagsm-server/api-design"><img src="https://agentmods.dev/badge/skills/themoment-team/datagsm-server/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/themoment-team/datagsm-server/api-design"><img src="https://agentmods.dev/badge/skills/themoment-team/datagsm-server/api-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 38 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 217 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

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	$0.00038	$0.00217
Opus 5.5	$0.00015	$0.00087
Sonnet 5.5	$0.00008	$0.00043
Haiku 4.5	$0.00004	$0.00022

Measured 29d ago against content hash 17b1e8bd0d91, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

api-design 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 29d 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.

.agents/skills/api-design/SKILL.md · 33 lines

What it actually says

REST API Design Guide

URL Design

RESTful principles: /v1/auth/api-keys
Use plural: /students, /clubs
Hierarchy: /students/{id}/projects

Query Parameters

Filtering: ?status=active
Pagination: ?page=0&size=20
Sorting: ?sort=createdAt,desc

OpenAPI Documentation

@Operation(summary = "Create API key", description = "...")
@ApiResponse(responseCode = "200", description = "Success")
@PostMapping("/api-keys")
fun create(@Valid @RequestBody reqDto: CreateApiKeyReqDto): ApiKeyResDto

Response Format

Success: CommonApiResponse(data = ...)
Error: ExpectedException → Global Handler

Changes

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.

29d ago First seen · 33 lines · 38 tokens per session scan A 17b1e8bd0d91

Subscribe to this mod's changes

api-design is a skill published in the GitHub repository themoment-team/datagsm-server (29 stars, last pushed yesterday), licensed MIT. It adds 38 tokens to every session and 217 once invoked, about $0.0002 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 2026-10-08.

Backend and APIs kotlin multi-module mysql redis spring-boot spring-data

api-design next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
api-designthemoment-team/datagsm-server	Skill	29	yesterday	MIT	A	38	Claude Code, Codex
spring-ecosystem-docspledgeandgrow/pledge-skills	Skill	10	3mo ago	MIT	A	43	Claude Code, Codex
zhihu-searchitwanger/toBeBetterJavaer	Skill	18k	2d ago	none	A	103	Claude Code, Codex
spring-mcp-contractsexplyt/spring-plugin	Skill	167	yesterday	Apache-2.0	A	102	Claude Code, Codex
spring-boot-developmentmanutej/luxor-claude-marketplace	Skill	63	4mo ago	none	A	31	Claude Code
java-cacheducpm2303/claude-java-plugins	Skill	17	7mo ago	none	A	46	Claude Code
apollo-routerclidey/whodb	Skill	5.0k	yesterday	Apache-2.0	A	140	Claude Code

datagsm-server: Skill for Claude Code