Understanding by Design Planner
THU-MAIC/OpenMAIC
Plans an OpenMAIC lesson or course series by backward design: enduring understandings and essential questions first, then performance evidence, then learning activities.
A skill your agent uses when planning or designing features and need to understand current codebase state, find existing patterns, or verify assumptions about what exists; when design makes…
No licenceAuto-check passed
Install Investigating A Codebase
$ npx skills add ed3dai/ed3d-plugins --skill investigating-a-codebase -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install ed3dai/ed3d-plugins investigating-a-codebase --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/ed3dai/ed3d-plugins.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/ed3d-research-agents/skills/investigating-a-codebase .claude/skills/investigating-a-codebase && 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 "investigating-a-codebase" agent skill from https://github.com/ed3dai/ed3d-plugins/tree/main/plugins/ed3d-research-agents/skills/investigating-a-codebase into .claude/skills/investigating-a-codebase/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "investigating-a-codebase", 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/ed3dai/ed3d-plugins/tree/main/plugins/ed3d-research-agents/skills/investigating-a-codebaseType 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 ed3dai/ed3d-plugins --skill investigating-a-codebase -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install ed3dai/ed3d-plugins investigating-a-codebase --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ed3dai/ed3d-plugins.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/ed3d-research-agents/skills/investigating-a-codebase .agents/skills/investigating-a-codebase && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "investigating-a-codebase" agent skill from https://github.com/ed3dai/ed3d-plugins/tree/main/plugins/ed3d-research-agents/skills/investigating-a-codebase into .agents/skills/investigating-a-codebase/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "investigating-a-codebase", 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 ed3dai/ed3d-plugins --skill investigating-a-codebase -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install ed3dai/ed3d-plugins investigating-a-codebase --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ed3dai/ed3d-plugins.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/ed3d-research-agents/skills/investigating-a-codebase .cursor/skills/investigating-a-codebase && 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 "investigating-a-codebase" agent skill from https://github.com/ed3dai/ed3d-plugins/tree/main/plugins/ed3d-research-agents/skills/investigating-a-codebase into .cursor/skills/investigating-a-codebase/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "investigating-a-codebase", 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/ed3dai/ed3d-plugins.git --path plugins/ed3d-research-agents/skills/investigating-a-codebase--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 ed3dai/ed3d-plugins --skill investigating-a-codebase -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install ed3dai/ed3d-plugins investigating-a-codebase --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ed3dai/ed3d-plugins.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/ed3d-research-agents/skills/investigating-a-codebase .gemini/skills/investigating-a-codebase && 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 "investigating-a-codebase" agent skill from https://github.com/ed3dai/ed3d-plugins/tree/main/plugins/ed3d-research-agents/skills/investigating-a-codebase into .gemini/skills/investigating-a-codebase/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "investigating-a-codebase", 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 ed3dai/ed3d-plugins investigating-a-codebaseInstalls 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 ed3dai/ed3d-plugins --skill investigating-a-codebase -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/ed3dai/ed3d-plugins.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/ed3d-research-agents/skills/investigating-a-codebase .github/skills/investigating-a-codebase && 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 "investigating-a-codebase" agent skill from https://github.com/ed3dai/ed3d-plugins/tree/main/plugins/ed3d-research-agents/skills/investigating-a-codebase into .github/skills/investigating-a-codebase/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "investigating-a-codebase", 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 ed3dai/ed3d-plugins --skill investigating-a-codebase -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install ed3dai/ed3d-plugins investigating-a-codebase --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ed3dai/ed3d-plugins.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/ed3d-research-agents/skills/investigating-a-codebase .opencode/skills/investigating-a-codebase && 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 "investigating-a-codebase" agent skill from https://github.com/ed3dai/ed3d-plugins/tree/main/plugins/ed3d-research-agents/skills/investigating-a-codebase into .opencode/skills/investigating-a-codebase/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "investigating-a-codebase", 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
investigating-a-codebase- GitHub stars
- 250
- Token cost
- ~1.3k tokens
- SKILL.md length
- 587 words
- Files
- 1
- Skills in repo
- 34
- Repo updated
- First seen
- Licence
- None found
At a glance
A skill your agent uses when planning or designing features and need to understand current codebase state, find existing patterns, or verify assumptions about what exists; when design makes…
- Works in 5 steps: Start with entry points - main files,… → Use multiple search strategies - Glob… → Follow traces - imports, references,… → …
- Designing features and need to understand current codebase state
- SKILL.md covers Overview, When to Use, Core Investigation Workflow and Verifying Design Assumptions, plus 4 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Investigating A Codebase is an agent skill from ed3dai/ed3d-plugins. Use when planning or designing features and need to understand current codebase state, find existing patterns, or verify assumptions about what exists; when design makes assumptions about file locations, structure, or existing code that need verification - prevents hallucination by grounding plans in reality
Its SKILL.md is about 1.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The repository describes itself as: Ed's repo of Claude Code plugins, centered around a research-plan-implement workflow. Only a tiny bit cursed. If you're lucky.
When your agent uses it
- Designing features and need to understand current codebase state
- Find existing patterns
- Verify assumptions about what exists
- Design makes assumptions about file locations
Example prompts
- “/investigating-a-codebase”
Workflow steps
5 steps, taken from the first numbered list in SKILL.md.
- Start with entry points - main files, index, package.json, config
- Use multiple search strategies - Glob patterns, Grep keywords, Read files
- Follow traces - imports, references, component relationships
- Verify don't assume - confirm file locations and structure
- Report definitively - exact paths or "not found" with search strategy
What it can do on your machine
Read from SKILL.md and the folder at commit 0c90f4b. 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.
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
Investigating A Codebase loads about 1.3k tokens when it runs. Until then it costs about 84 tokens; SKILL.md has 587 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
Without a licence we can't republish the file, so here is its outline and opening line. It has 587 words (~1,295 tokens).
“Understand current codebase state to ground planning and design decisions in reality, not assumptions. Find existing patterns, verify design assumptions, and provide definitive answers about what exists and where.”
- name
- investigating-a-codebase
- user-invocable
- false
Files
Just SKILL.md in plugins/ed3d-research-agents/skills/investigating-a-codebase of ed3dai/ed3d-plugins.
Open the folder on GitHubat commit 0c90f4b
Compare with similar skills
Investigating A Codebase 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 |
|---|---|---|---|---|---|---|
| Investigating A Codebase this skilled3dai/ed3d-plugins | 250 | — | ~1.3k | Automated safety check: Pass | None | |
| Understanding by Design PlannerTHU-MAIC/OpenMAIC | 40k | — | ~548 | Automated safety check: Pass | MIT | |
| Design Systemaffaan-m/ECC | 274k | — | ~698 | Automated safety check: Pass | MIT | |
| Design Guidepaperclipai/paperclip | 98k | 1 repos | ~3.1k | Automated safety check: Pass | MIT | |
| Design Audit Against Rams' Principlesthedotmack/claude-mem | 97k | — | ~4.6k | Automated safety check: Pass | Apache-2.0 | |
| Figma Design to Codewarpdotdev/warp | 65k | 4 repos | ~2.9k | Automated safety check: Pass | AGPL-3.0 |
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Questions about Investigating A Codebase
What does Investigating A Codebase do?
A skill your agent uses when planning or designing features and need to understand current codebase state, find existing patterns, or verify assumptions about what exists; when design makes…. Investigating A Codebase is an agent skill from ed3dai/ed3d-plugins.
When should I use Investigating A Codebase?
Investigating A Codebase fits situations like: designing features and need to understand current codebase state; find existing patterns; verify assumptions about what exists; design makes assumptions about file locations.
How do I install Investigating A Codebase in Claude Code?
Run `npx skills add ed3dai/ed3d-plugins --skill investigating-a-codebase -a claude-code`. Or copy the skill folder (plugins/ed3d-research-agents/skills/investigating-a-codebase in ed3dai/ed3d-plugins) into .claude/skills/investigating-a-codebase in your project. Claude Code loads it when a task matches its description.
How do I install Investigating A Codebase in Codex?
Run `npx skills add ed3dai/ed3d-plugins --skill investigating-a-codebase -a codex`. Or copy the skill folder (plugins/ed3d-research-agents/skills/investigating-a-codebase in ed3dai/ed3d-plugins) into .agents/skills/investigating-a-codebase in your project. Codex loads it when a task matches its description.
Can I use Investigating A Codebase 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 ed3dai/ed3d-plugins --skill investigating-a-codebase -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/investigating-a-codebase, .gemini/skills/investigating-a-codebase, .github/skills/investigating-a-codebase and .opencode/skills/investigating-a-codebase in your project.
What does Investigating A Codebase need to run?
SKILL.md names no scripts, command-line tools or credentials: Investigating A Codebase is instructions for the agent only.
Does Investigating A Codebase 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 Investigating A Codebase 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 Investigating A Codebase use?
No licence was found for Investigating A Codebase or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.
How many tokens does Investigating A Codebase use?
About 1.3k tokens (SKILL.md is roughly 5.2k 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 Investigating A Codebase?
Skills that share tags, products or a category with Investigating A Codebase: Understanding by Design Planner (THU-MAIC/OpenMAIC, 40k stars), Design System (affaan-m/ECC, 274k stars), Design Guide (paperclipai/paperclip, 98k stars) and Design Audit Against Rams' Principles (thedotmack/claude-mem, 97k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Investigating A Codebase?
ed3dai (a GitHub organization) maintains it in ed3dai/ed3d-plugins, which has 250 GitHub stars. The repository holds 34 skills in this directory. The repository was last updated on September 6, 2026.
Source: ed3dai/ed3d-plugins on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.