using-sdd

using-sdd is a skill for Claude Code from tranhieutt/software_development_department. It costs 43 tokens per session (2,676 once invoked), scanned A, original, MIT.

A routing layer for a structured software-development process. It decides which workflow should govern a request before an agent asks questions, edits files, delegates work, or claims completion.

In plain words
What is it for?
Use it at the start of software work to select the relevant development workflow and keep the task aligned with the project's defined lifecycle.
Why use it?
It prevents development tasks from skipping the appropriate planning, building, verification, review, or shipping stage. It also directs requests to specialist procedures when needed.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: agent in frontmatter; mentions subagents; mentions Claude Code.

Good fit Use it at the start of software work to select the relevant development workflow and keep the task aligned with the project's defined lifecycle.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/tranhieutt/software_development_department/using-sdd
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.

Any agent
npx skills add tranhieutt/software_development_department --skill using-sdd
Clone the repo
git clone --depth 1 https://github.com/tranhieutt/software_development_department

Made for: Claude Code.

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.

agentmods badge for using-sdd

README.md
[![agentmods](https://agentmods.dev/badge/skills/tranhieutt/software_development_department/using-sdd/github.svg)](https://agentmods.dev/skills/tranhieutt/software_development_department/using-sdd)
Your own site
<a href="https://agentmods.dev/skills/tranhieutt/software_development_department/using-sdd"><img src="https://agentmods.dev/badge/skills/tranhieutt/software_development_department/using-sdd/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.

agentmods 80×15 button for using-sdd

Your own site · 80×15
<a href="https://agentmods.dev/skills/tranhieutt/software_development_department/using-sdd"><img src="https://agentmods.dev/badge/skills/tranhieutt/software_development_department/using-sdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,676 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00043 $0.02676
Opus 5 $0.00022 $0.01338
Sonnet 5 $0.00009 $0.00535
Haiku 4.5 $0.00004 $0.00268

Measured 8d ago against content hash b9a9d88efa38, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

using-sdd 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 8d 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.

.claude/skills/using-sdd/SKILL.md · 257 lines

How it starts

The opening of the file, as written. The whole thing — 257 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Using SDD

using-sdd is the router and discipline layer for the Software Development Department. It does not replace specialist skills. It decides which SDD workflow must govern the current request before the agent acts.

For phase orientation, use docs/technical/SDD_LIFECYCLE_MAP.md (DEFINE -> PLAN -> BUILD -> VERIFY -> REVIEW -> SHIP). For detailed runtime stage rules, use docs/technical/CONTROL_PLANE_MAP.md.

Core Rule

Before answering, asking clarifying questions, editing files, spawning agents, or claiming completion, check whether an SDD skill applies.

If a skill applies, use it. Do not rely on memory of the skill. Read the current skill and follow its gates.

Skill Routing

User intent or situation Required SDD workflow
Codex environment, Codex setup, AGENTS.md, .codex, Claude-to-Codex tool mapping, or SDD outside Claude Code codex-sdd then route through using-sdd
First session, unclear project state start
Vague product idea, ideation, product direction brainstorm
User wants structured requirements or says "ask me", "don't assume", "interview" deep-interview
New feature, behavior change, architectural change spec-driven-development
Existing spec needs readiness review before planning or implementation review-spec
Approved spec conflicts with code, tests, review findings, user feedback, or platform reality spec-evolution
Framework, library, external API, platform behavior, deprecation, migration, or "latest/official/best practice" correctness matters source-driven-development
Epic, multi-step work, large prompt, many files planning-and-task-breakdown
Implementation of one approved task test-driven-development
Execution of approved multi-task sequential plan with review gates subagent-driven-development
Bug, failing test, build failure, CI failure, performance regression, or unexpected behavior systematic-debugging
Complex, intermittent, unfamiliar, or repeatedly failed bug investigation diagnose
Simple obvious bug with clear cause test-driven-development with a regression test
Coordinated multi-agent work across domains orchestrate
Independent parallel workstreams fork-join
UI/frontend architecture or component design frontend-design or ui-spec
API contract or endpoint design api-design
Architecture decision with durable consequences architecture-decision-records
Code quality, PR review, merge readiness code-review or code-review-checklist
Prose quality for specs, ADRs, PR bodies, release notes, or technical docs style-review
Behavior-preserving cleanup, simplification, readability refactor, or complexity reduction after tests pass code-simplification
Review comments, PR feedback, CHANGES_REQUIRED verdict, or reviewer questions need response receiving-code-review
Phase transition or readiness review gate-check
Release or launch preparation release-checklist or launch-checklist
Completion claim, success claim, task done, fixed, passing, ready, clean, merge-ready verification-before-completion
Commit requested commit
Create, update, refine, or evaluate an SDD skill; repeated prompt should become a skill; agent failure suggests missing/broken skill learner
Save reusable lesson or preference learner or annotate
Context is too large or stale context-engineering or save-state

Read the full file on GitHub · 257 lines

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. 8d ago First seen · 257 lines · 43 tokens per session scan A b9a9d88efa38

Subscribe to this mod's changes

using-sdd is a skill published in the GitHub repository tranhieutt/software_development_department (72 stars, last pushed 4mo ago), licensed MIT. It adds 43 tokens to every session and 2,676 once invoked, about $0.0002 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 2026-09-03.

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