Engineering Plan Review
garrytan/gstack
Reviews an execution plan or design doc before coding, covering architecture, data flow, edge cases, test coverage and performance, one issue at a time.
Guides the creation of technical design documents before writing code, producing architecture diagrams, data models, API interface definitions, implementation plans, and multi-option trade-off…
Install Design First
$ npx skills add rohitg00/skillkit --skill design-first -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install rohitg00/skillkit design-first --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/rohitg00/skillkit.git skills-src && mkdir -p .claude/skills && cp -r skills-src/packages/core/src/methodology/packs/planning/design-first .claude/skills/design-first && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "design-first" agent skill from https://github.com/rohitg00/skillkit/tree/main/packages/core/src/methodology/packs/planning/design-first into .claude/skills/design-first/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "design-first", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/rohitg00/skillkit/tree/main/packages/core/src/methodology/packs/planning/design-firstType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add rohitg00/skillkit --skill design-first -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install rohitg00/skillkit design-first --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/rohitg00/skillkit.git skills-src && mkdir -p .agents/skills && cp -r skills-src/packages/core/src/methodology/packs/planning/design-first .agents/skills/design-first && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "design-first" agent skill from https://github.com/rohitg00/skillkit/tree/main/packages/core/src/methodology/packs/planning/design-first into .agents/skills/design-first/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "design-first", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add rohitg00/skillkit --skill design-first -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install rohitg00/skillkit design-first --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/rohitg00/skillkit.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/packages/core/src/methodology/packs/planning/design-first .cursor/skills/design-first && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "design-first" agent skill from https://github.com/rohitg00/skillkit/tree/main/packages/core/src/methodology/packs/planning/design-first into .cursor/skills/design-first/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "design-first", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/rohitg00/skillkit.git --path packages/core/src/methodology/packs/planning/design-first--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add rohitg00/skillkit --skill design-first -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install rohitg00/skillkit design-first --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/rohitg00/skillkit.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/packages/core/src/methodology/packs/planning/design-first .gemini/skills/design-first && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "design-first" agent skill from https://github.com/rohitg00/skillkit/tree/main/packages/core/src/methodology/packs/planning/design-first into .gemini/skills/design-first/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "design-first", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install rohitg00/skillkit design-firstInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add rohitg00/skillkit --skill design-first -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/rohitg00/skillkit.git skills-src && mkdir -p .github/skills && cp -r skills-src/packages/core/src/methodology/packs/planning/design-first .github/skills/design-first && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "design-first" agent skill from https://github.com/rohitg00/skillkit/tree/main/packages/core/src/methodology/packs/planning/design-first into .github/skills/design-first/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "design-first", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add rohitg00/skillkit --skill design-first -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install rohitg00/skillkit design-first --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/rohitg00/skillkit.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/packages/core/src/methodology/packs/planning/design-first .opencode/skills/design-first && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "design-first" agent skill from https://github.com/rohitg00/skillkit/tree/main/packages/core/src/methodology/packs/planning/design-first into .opencode/skills/design-first/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "design-first", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
design-first- GitHub stars
- 1.5k
- Token cost
- ~1.5k tokens
- SKILL.md length
- 494 words
- Files
- 1
- Skills in repo
- 14
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
Guides the creation of technical design documents before writing code, producing architecture diagrams, data models, API interface definitions, implementation plans, and multi-option trade-off…
- Works in 4 steps: Understand the Problem → Explore Options → Design the Solution → …
- The user asks to plan a feature
- SKILL.md covers Core Principle, When to Use Design First, Design Process and Design Document Template, plus 4 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Design First is an agent skill from rohitg00/skillkit. Guides the creation of technical design documents before writing code, producing architecture diagrams, data models, API interface definitions, implementation plans, and multi-option trade-off analyses. Use when the user asks to plan a feature, architect a system, design an API, explore implementation approaches, or requests a technical design or spec before coding — especially for complex features involving multiple components, ambiguous requirements, or significant architectural changes.
Its SKILL.md is about 1.5k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Agent Workflows, covering Planning, Diagrams and Software architecture. The repository describes itself as: Supercharge AI coding agents with portable skills. Install, translate & share skills across Claude Code, Cursor, Codex, Copilot & 40 more. The licence is Apache-2.0.
When your agent uses it
- The user asks to plan a feature
- Architect a system
- Explore implementation approaches
- Requests a technical design
Example prompts
- “Use the design-first skill to guide the creation of technical design documents before writing code, producing architecture diagrams, data models…”
- “/design-first”
Workflow steps
4 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit d2e5c34. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are typescript and markdown).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Design First loads about 1.5k tokens when it runs. Until then it costs about 127 tokens; SKILL.md has 494 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from rohitg00/skillkit at commit d2e5c34, republished under its Apache-2.0 licence (© rohitg00). 494 words, ~1,459 tokens.
Download SKILL.mdSave it as
.claude/skills/design-first/SKILL.md (or your agent's skills folder).- name
- design-first
- description
- Guides the creation of technical design documents before writing code, producing architecture diagrams, data models, API interface definitions, implementation plans, and multi-option trade-off analyses. Use when the user asks to plan a feature, architect a system, design an API, explore implementation approaches, or requests a technical design or spec before coding — especially for complex features involving multiple components, ambiguous requirements, or significant architectural changes.
- version
- 1.0.0
- triggers
- design first, plan before code, architecture, how should I implement, design document
- tags
- planning, design, architecture, thinking
- difficulty
- intermediate
- estimatedTime
- 20
- relatedSkills
- planning/task-decomposition, planning/verification-gates
Design First Methodology
You are following a design-first approach. Before writing any code, design the solution.
Core Principle
Think first, code second.
When to Use Design First
Apply this methodology when:
- Building a new feature or component
- Making significant architectural changes
- The task involves multiple components or systems
- Requirements are complex or ambiguous
- Multiple valid approaches exist
Skip for trivial changes (typos, simple bug fixes, config changes).
Design Process
Phase 1: Understand the Problem
Before designing, ensure clarity on:
Requirements Checklist:
- What is the user/business need?
- What are the inputs and outputs?
- What are the constraints (performance, security, compatibility)?
- What are the edge cases?
- What are the non-requirements (out of scope)?
Questions to Ask:
- What exactly should this do?
- What should it NOT do?
- How will users interact with it?
- How will it integrate with existing systems?
- What happens when things go wrong?
Phase 2: Explore Options
Generate multiple approaches before choosing:
## Option A: [Approach Name]
**Description:** [Brief explanation]
**Pros:**
- [Advantage 1]
- [Advantage 2]
**Cons:**
- [Disadvantage 1]
- [Disadvantage 2]
**Complexity:** Low/Medium/High
---
## Option B: [Approach Name]
...Evaluate options against:
- Requirements fit
- Implementation complexity
- Maintenance burden
- Performance characteristics
- Team familiarity
Phase 3: Design the Solution
Create a design document covering:
System Overview
┌─────────────┐ ┌─────────────┐ ┌─────────────┐
│ Client │───▶│ Service │───▶│ Database │
└─────────────┘ └─────────────┘ └─────────────┘Data Model
interface Order {
id: string;
customerId: string;
items: OrderItem[];
status: OrderStatus;
createdAt: Date;
total: Money;
}API/Interface Design
// Public interface
interface OrderService {
createOrder(customerId: string, items: OrderItem[]): Promise<Order>;
getOrder(orderId: string): Promise<Order | null>;
cancelOrder(orderId: string): Promise<void>;
}Key Algorithms/Logic
Order Total Calculation:
1. Sum item prices (price × quantity)
2. Apply discounts (percentage-based first, then fixed)
3. Calculate tax (rate based on customer location)
4. Add shipping (free over threshold, otherwise flat rate)Error Handling
- What errors can occur?
- How should they be handled?
- What should users see?
Phase 4: Validate the Design
Before implementing, validate:
Self-Review:
- Does it meet all requirements?
- Are there simpler alternatives?
- What could go wrong?
- Is it testable?
External Validation:
- Rubber duck explanation (explain to yourself/others)
- Quick review with teammate
- Check against similar patterns in codebase
Design Document Template
Use DESIGN_TEMPLATE.md as the standard artifact for each feature. It covers:
- Overview — one-paragraph summary of what is being built and why
- Requirements — functional and non-functional (performance, security)
- Architecture — component diagram and explanation
- Data Model — entity definitions and relationships
- API Design — interface definitions
- Key Decisions — decision table with options considered, choice made, and rationale
- Implementation Plan — ordered steps
- Testing Strategy — unit and integration test scope
- Open Questions — unresolved items
Create this file at the start of each design session and keep it updated as the design evolves.
Show full SKILL.md (164 more words)Show less
Design Levels
High-Level Design (Architecture)
- System components and their interactions
- Data flow between systems
- Technology choices
- Deployment architecture
Mid-Level Design (Module/Component)
- Class/module structure
- Interfaces and contracts
- State management
- Error handling strategy
Low-Level Design (Implementation)
- Algorithm details
- Data structures
- Method signatures
- Edge case handling
Anti-Patterns to Avoid
| Anti-Pattern | Mitigation |
|---|---|
| Big Design Up Front (BDUF) | Design enough to start; refine as you learn |
| Analysis Paralysis | Time-box the design phase; decide at 70% confidence |
| Design in Isolation | Align with existing codebase patterns and team conventions |
Integration with Implementation
After design is approved:
- Review the design one more time before coding
- Break into tasks using task-decomposition skill
- Implement incrementally - verify design assumptions as you code
- Update design if you discover issues during implementation
The design document is living — update it as you learn.
Signals You Need More Design
- "I'm not sure where to start"
- "This is getting complicated"
- "I keep refactoring"
- "The requirements are unclear"
- "Multiple approaches seem valid"
Stop and design before proceeding.
© rohitg00, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in packages/core/src/methodology/packs/planning/design-first of rohitg00/skillkit.
Open the folder on GitHubat commit d2e5c34
Compare with similar skills
Design First next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Design First this skillrohitg00/skillkit | 1.5k | — | ~1.5k | Automated safety check: Pass | Apache-2.0 | |
| Engineering Plan Reviewgarrytan/gstack | 136k | — | ~13k | Automated safety check: Notes | MIT | |
| Plan Previewu-ichi/reviewable-html-workbench | 298 | 1 repos | ~1.8k | Automated safety check: Pass | MIT | |
| Solution ArchitectIBM/ibm-watsonx-orchestrate-adk | 178 | — | ~8.4k | Automated safety check: Pass | MIT | |
| Cl Executeclosedloop-ai/claude-plugins | 122 | — | ~6.4k | Automated safety check: Pass | Apache-2.0 | |
| Plannotator Visual Explainerbacknotprop/plannotator | 9.2k | — | ~1.7k | Automated safety check: Pass | Apache-2.0 |
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Related
Categories
Questions about Design First
What does Design First do?
Guides the creation of technical design documents before writing code, producing architecture diagrams, data models, API interface definitions, implementation plans, and multi-option trade-off…. Design First is an agent skill from rohitg00/skillkit. Guides the creation of technical design documents before writing code, producing architecture diagrams, data models, API interface definitions, implementation plans, and multi-option trade-off analyses.
When should I use Design First?
Design First fits situations like: the user asks to plan a feature; architect a system; explore implementation approaches; requests a technical design.
How do I install Design First in Claude Code?
Run `npx skills add rohitg00/skillkit --skill design-first -a claude-code`. Or copy the skill folder (packages/core/src/methodology/packs/planning/design-first in rohitg00/skillkit) into .claude/skills/design-first in your project. Claude Code loads it when a task matches its description.
How do I install Design First in Codex?
Run `npx skills add rohitg00/skillkit --skill design-first -a codex`. Or copy the skill folder (packages/core/src/methodology/packs/planning/design-first in rohitg00/skillkit) into .agents/skills/design-first in your project. Codex loads it when a task matches its description.
Can I use Design First in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add rohitg00/skillkit --skill design-first -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/design-first, .gemini/skills/design-first, .github/skills/design-first and .opencode/skills/design-first in your project.
What does Design First need to run?
SKILL.md names no scripts, command-line tools or credentials: Design First is instructions for the agent only.
Does Design First access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Design First safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Design First use?
Design First is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Design First use?
About 1.5k tokens (SKILL.md is roughly 5.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Design First?
Skills that share tags, products or a category with Design First: Engineering Plan Review (garrytan/gstack, 136k stars), Plan Preview (u-ichi/reviewable-html-workbench, 298 stars), Solution Architect (IBM/ibm-watsonx-orchestrate-adk, 178 stars) and Cl Execute (closedloop-ai/claude-plugins, 122 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Design First?
rohitg00 (a GitHub user) maintains it in rohitg00/skillkit, which has 1,546 GitHub stars. The repository holds 14 skills in this directory. The repository was last updated on June 2, 2026.
Source: rohitg00/skillkit on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.