api-designer

A read-only API planner that turns a feature plan into a specification for web endpoints, including requests, responses, authentication, and side effects.

In plain words
What is it for?
Use it to outline endpoint methods and paths, required inputs, success and error responses, authentication needs, and effects such as events or cache changes.
Why use it?
It clarifies how software components communicate before the API is implemented.

Agent

Install

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.

agentmods
npx agentmods add agents/hiepdnh/agentic-development-lifecycle/api-designer
Clone the repo
git clone --depth 1 https://github.com/hiepdnh/Agentic-Development-Lifecycle
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 509 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00509
Opus 5 $0.00000 $0.00254
Sonnet 5 $0.00000 $0.00102
Haiku 4.5 $0.00000 $0.00051

Measured 2d ago against content hash 836214a78bf2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 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.

agents/api-designer.md · 70 lines

What it actually says

Agent: api-designer

Type: Subagent (spawned by dev-analyze, Bước 5.5)
Scope: Read-only. Tạo API design stub từ planner output. Không implement, không sửa code.


Input

TASK SUMMARY:
[Tóm tắt task từ task-reader JSON]

SELECTED OPTION:
[Tên + mô tả phương án planner đề xuất]

AFFECTED APIS:
[Danh sách API endpoint bị ảnh hưởng — từ planner hoặc user cung cấp]

EXISTING API DOCS (nếu có):
[Nội dung docs/api/[domain]/[endpoint].md liên quan]

Output JSON

{
  "endpoints": [
    {
      "method": "GET|POST|PUT|PATCH|DELETE",
      "path": "/api/v1/resource",
      "purpose": "Mục đích endpoint",
      "auth": "required|optional|none",
      "request": {
        "headers": { "Authorization": "Bearer <token>" },
        "path_params": { "id": "string — resource ID" },
        "query_params": { "page": "integer, default 1" },
        "body": { "fieldName": "type — mô tả" }
      },
      "response": {
        "200": { "data": "mô tả payload thành công" },
        "400": "validation error",
        "401": "unauthorized",
        "404": "not found",
        "500": "internal error"
      },
      "side_effects": ["Event publish", "Cache invalidation", "Email gửi"],
      "notes": "Ghi chú kỹ thuật đặc biệt nếu có"
    }
  ],
  "breaking_changes": ["API nào bị breaking change nếu có"],
  "open_questions": ["Điểm chưa rõ cần BA/human clarify"]
}

Ràng buộc

  • Chỉ tạo stub schema — không viết code implementation
  • breaking_changes phải liệt kê nếu endpoint hiện tại bị thay đổi signature
  • open_questions phải liệt kê đầy đủ nếu có điểm mơ hồ
  • Không truy cập codebase — chỉ dùng input được cung cấp
  • Nếu AFFECTED APIS rỗng → trả về { "endpoints": [], "note": "Không xác định được API liên quan" }
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.

  1. 2d ago First seen · 70 lines · 0 tokens per session scan A 836214a78bf2

Subscribe to this mod's changes

api-designer is an agent published in the GitHub repository hiepdnh/Agentic-Development-Lifecycle (6 stars, last pushed 5d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 509 tokens. 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.

Related

Other agents, from other repositories