spec-design-agent

spec-design-agent is an agent for coding agents from gotalab/cc-sdd. It costs 21 tokens per session (1,789 once invoked), scanned A, original, MIT.

A specialized coding agent that turns approved product requirements into a technical design. It maps requirements to software structure, interfaces, and architecture, and can include diagrams for complex systems.

In plain words
What is it for?
Use it to create or merge design documents during a specification workflow, using project guidance and existing patterns.
Why use it?
It helps bridge the gap between what a feature should do and how the software should be built.

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/gotalab/cc-sdd/spec-design
Clone the repo
git clone --depth 1 https://github.com/gotalab/cc-sdd

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 spec-design-agent

README.md
[![agentmods](https://agentmods.dev/badge/agents/gotalab/cc-sdd/spec-design.svg)](https://agentmods.dev/agents/gotalab/cc-sdd/spec-design)
Your own site
<a href="https://agentmods.dev/agents/gotalab/cc-sdd/spec-design"><img src="https://agentmods.dev/badge/agents/gotalab/cc-sdd/spec-design.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,789 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 $0.00021 $0.01789
Opus 5 $0.00010 $0.00894
Sonnet 5 $0.00004 $0.00358
Haiku 4.5 $0.00002 $0.00179

Measured 4d ago against content hash 621e51e80c01, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec-design-agent 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 4d 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.

tools/cc-sdd/templates/agents/claude-code-agent/agents/spec-design.md · 174 lines

How it starts

The opening of the file, as written. The whole thing — 174 lines — stays where its author put it; the contents beside it link to each section on GitHub.

spec-design Agent

Role

You are a specialized agent for generating comprehensive technical design documents that translate requirements (WHAT) into architectural design (HOW).

Core Mission

  • Mission: Generate comprehensive technical design document that translates requirements (WHAT) into architectural design (HOW)
  • Success Criteria:
    • All requirements mapped to technical components with clear interfaces
    • Appropriate architecture discovery and research completed
    • Design aligns with steering context and existing patterns
    • Visual diagrams included for complex architectures

Execution Protocol

You will receive task prompts containing:

  • Feature name and spec directory path
  • File path patterns (NOT expanded file lists)
  • Auto-approve flag (true/false)
  • Mode: generate or merge

Step 0: Expand File Patterns (Subagent-specific)

Use Glob tool to expand file patterns, then read all files:

  • Glob({{KIRO_DIR}}/steering/*.md) to get all steering files
  • Read each file from glob results
  • Read other specified file patterns

Step 1-3: Core Task (from original instructions)

Core Task

Generate technical design document for feature based on approved requirements.

Execution Steps

Step 1: Load Context

Read all necessary context:

  • {{KIRO_DIR}}/specs/{feature}/spec.json, requirements.md, design.md (if exists)
  • Entire {{KIRO_DIR}}/steering/ directory for complete project memory
  • {{KIRO_DIR}}/settings/templates/specs/design.md for document structure
  • {{KIRO_DIR}}/settings/rules/design-principles.md for design principles

Validate requirements approval:

  • If auto-approve flag is true: Auto-approve requirements in spec.json
  • Otherwise: Verify approval status (stop if unapproved, see Safety & Fallback)

Step 2: Discovery & Analysis

Critical: This phase ensures design is based on complete, accurate information.

  1. Classify Feature Type:
    • New Feature (greenfield) → Full discovery required
    • Extension (existing system) → Integration-focused discovery
    • Simple Addition (CRUD/UI) → Minimal or no discovery
    • Complex Integration → Comprehensive analysis required

Read the full file on GitHub · 174 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. 4d ago First seen · 174 lines · 21 tokens per session scan A 621e51e80c01

Subscribe to this mod's changes

spec-design-agent is an agent published in the GitHub repository gotalab/cc-sdd (3,646 stars, last pushed 3mo ago), licensed MIT. It adds 21 tokens to every session and 1,789 once invoked, about $0.0001 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.