eli5

The saved excerpt is a snapshot from when this skill was listed. The external source remains the complete and most current version.

---
name: eli5
description: "WHAT: Explains a codebase, a folder, a feature, a command or a pull request to someone who knows nothing about it, as a PR Lens canvas whose walkthrough builds the picture one part at a time. WHEN: /eli5 <thing>, or asked to explain code simply, for a beginner, a new hire, a non-engineer, or 'like I'm five'. KEYWORDS: eli5, explain like I'm five, explain simply, beginner, onboarding, walkthrough, diagram, PR Lens"
---

# eli5

Explain like I'm someone who knows nothing about this code: one sentence, then one part at a time, until the whole picture is on screen and the reader already knows every part of it.

A reader who knows nothing cannot take in a diagram. They can take in two boxes and an arrow. So the canvas starts with two boxes and grows. The whole picture is the last thing they see, not the first, and by then it holds nothing new.

You write one graph document. Its views are the growing pictures, its walkthrough plays them in order, and PR Lens draws them. The reader opens a link and presses play. There is no page, no list, no paragraph.

## What you need

The PR Lens manual and its reference pages. The PR Lens CLI prints both. Run `npx @coldtea/pr-lens-cli@latest skill`, then `npx @coldtea/pr-lens-cli@latest skill references`, and read both before your first document. The manual's rules hold here except where this page marks an **Override**.

## Operating manual

1. **Write the answer first.** Read the code until you can say what it does for a person, in under 48 characters, because the sentence is also a walkthrough heading and a heading stops at 48. Count them.
   - For a feature or a command: "When you ___, this code ___." Example: "When you hit send, it emails everyone."
   - For a whole codebase: what the product is for. Example: "BestRegards sends newsletters for you." The sentence is about the product, not one path through it.
   **Override, summary.** The sentence is also the document `summary`. The reference wants a paragraph about a change; eli5 wants this sentence.

2. **Cut to the path.** For a feature, trace the one path input takes to output. For a whole codebase, first list the 3 to 5 things a person does with the product, then trace the path of the main one: the thing the product is named after or sold on, or the one with the most code on it. The parts on that path are the diagram: 4 to 10 nodes, 2 to 5 lanes. Helpers, config, types and tests stay out. When two entry points converge on the same code, draw the point where they meet and name both in its body; do not drop one.

3. **Write `.pr-lens/graph.json`.** Follow `references/graph-document.md`, plus these rules:
   - **Override, provenance.** The schema requires it. Take the remote from `git remote get-url origin`. `https://github.com/acme/mail.git` and `[email protected]:acme/mail.git` both become `{ "owner": "acme", "name": "mail", "host": "github.com" }`. Put the current `HEAD` sha in both `base.sha` and `head.sha`. The parser rule about "a patch whose two commits are the same" is about `patch`, not `provenance`, so this validates.
   - Lanes are places the reader can picture, left to right in the order the path runs: "your browser", "the website", "the mail company", "your reader". Not the folder tree. Set `order`. A database or queue the path touches more than once is not a place on the path; put it in the lane of the code that owns it.
   - The first node is the reader, or the thing the reader touches: "You write the email". The reader must find themself on the first picture. Use `kind: "external"` for a person; the schema has no person kind.
   - Node `label` is what the part does, in three words or fewer. The real name goes in `subtitle`, the file in `files`.
   - **Override, deltas.** Every `delta` is `unchanged` unless the thing is a pull request.
   - No `stats`. There is no diff to count.
   - Exactly one edge with `emphasis: "hero"`: the hand-off the answer sentence is about, the one edge that, if removed, wou