Learn Codebase

What it does

When your agent uses it

• Asks to learn this codebase
• Give me a codebase overview
• Onboard me to this project
• Explain the architecture

Example prompts

• “learn this codebase”
• “give me a codebase overview”
• “onboard me to this project”
• “/learn-codebase”

Requirements

• Compatibility (from SKILL.md): Requires grepika MCP server.
• Pre-approved tools (allowed-tools): mcp__grepika__search, mcp__grepika__toc, mcp__grepika__stats, mcp__grepika__outline, mcp__grepika__get, mcp__grepika__graph, mcp__grepika__structural_search, mcp__grepika__add_workspace

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

1. 1Get codebase statistics
2. 2Show directory structure
3. 3Find key files for the area
4. 4Extract structure of main files
5. 5Read key sections

What it can do on your machine

Read from SKILL.md and the folder at commit f035a18. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • mcp__grepika__search
  • mcp__grepika__toc
  • mcp__grepika__stats
  • mcp__grepika__outline
  • mcp__grepika__get
  • mcp__grepika__graph
  • mcp__grepika__structural_search
  • mcp__grepika__add_workspace

  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.

• Compatibility

  Requires grepika MCP server.

  From compatibility in the SKILL.md frontmatter.

Context cost

Learn Codebase loads about 922 tokens when it runs, and up to ~2.2k if it reads all its reference files. Until then it costs about 64 tokens; SKILL.md has 219 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~64

When it runs · the whole SKILL.md, loaded when a task matches

~922

With references · SKILL.md plus every file in references/, read only if the agent opens them

~2.2k

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

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 adamthewilliam/grepika at commit f035a18, republished under its MIT licence (© adamthewilliam). 219 words, ~922 tokens.

name

learn-codebase

description

This skill should be used when the user asks to "learn this codebase", "give me a codebase overview", "onboard me to this project", "explain the architecture", or mentions keywords related to understanding codebase structure and architecture.

allowed-tools

mcp__grepika__search, mcp__grepika__toc, mcp__grepika__stats, mcp__grepika__outline, mcp__grepika__get, mcp__grepika__graph, mcp__grepika__structural_search, mcp__grepika__add_workspace

compatibility

Requires grepika MCP server.

version

1.1.0

disable-model-invocation

true

context

fork

agent

Explore

model

haiku

## Codebase Overview

### Statistics
- **Languages**: [breakdown]
- **Total files**: [count]
- **Lines of code**: [estimate]

### Directory Structure
[tree view with annotations]

### Architecture Summary
[2-3 paragraphs explaining the high-level design]

### Key Modules
| Module | Location | Purpose |
|--------|----------|---------|
| [name] | [path] | [what it does] |

### Entry Points
- **Main**: [path] - [description]
- **API**: [path] - [description]
- **CLI**: [path] - [description]

### Configuration
- [list config files and their purposes]

### Recommended Reading Order
1. [file] - Start here to understand [concept]
2. [file] - Then learn about [concept]
3. [file] - Finally explore [concept]

## Understanding: [area]

### Overview
[what this area does and why it exists]

### Key Files
| File | Purpose | Key Exports |
|------|---------|-------------|
| [path] | [purpose] | [exports] |

### Data Flow
[how data moves through this area]

### Dependencies
- **Uses**: [what this area depends on]
- **Used by**: [what depends on this area]

### Key Concepts
- **[concept 1]**: [explanation]
- **[concept 2]**: [explanation]

### Code Patterns
[common patterns used in this area]

### Getting Started
[how to make your first change in this area]

© adamthewilliam, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (references) in plugins/grepika/skills/learn-codebase of adamthewilliam/grepika.

• SKILL.md
• references/onboarding-strategies.md

Open the folder on GitHubat commit f035a18