explain-code

A command that explains an unfamiliar file, function, class, or module, including what it does, how it works, and why it is structured that way.

In plain words
What is it for?
Use it when onboarding to a codebase, studying an algorithm, tracing a symbol, or preparing to modify code you have not read before.
Why use it?
It shortens the time needed to understand existing code before changing it. It also checks related imports, callers, comments, and recent history for context.

Command for Claude Code

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 commands/khaledsaeed18/dotclaude/explain-code
Clone the repo
git clone --depth 1 https://github.com/KhaledSaeed18/dotclaude

Made for: Claude Code.

Per session 86 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 657 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 $0.00086 $0.00657
Opus 5 $0.00043 $0.00329
Sonnet 5 $0.00017 $0.00131
Haiku 4.5 $0.00009 $0.00066

Measured yesterday against content hash f6d82c2fddb2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

explain-code 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 yesterday.

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.

.claude-plugin/plugins/engineering/commands/explain-code.md · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Context

Target: $ARGUMENTS

Task

Explain the code at $ARGUMENTS clearly enough that a developer who has never seen it can understand what it does, how it works, and what to know before touching it.

If no argument was given, ask for a file path or symbol name and stop.

Step 1: Locate the target

If $ARGUMENTS is a file path, read it directly. If it names a function, class, or type:

grep -rn "$ARGUMENTS" --include="*.ts" --include="*.tsx" --include="*.js" --include="*.jsx" --include="*.py" --include="*.go" --include="*.rs" . | grep -v node_modules | head -20

Read the definition first, then any imports it pulls in, then its primary callers (at most two or three) to understand how it is used in practice.

Step 2: Understand the context

Check what changed recently and why:

git log --oneline -10 -- "$ARGUMENTS" 2>/dev/null

If there is meaningful history, note whether the code has evolved significantly or is stable. Look for any comments explaining non-obvious decisions.

Step 3: Explain

Structure the explanation as follows:

What it does: One or two sentences. The observable purpose from the caller's perspective, not the implementation.

How it works: Walk through the key logic step by step. Use concrete examples where the code operates on data (show what goes in, what comes out). For complex control flow, trace the main path first, then branches. Skip boilerplate that does not add to understanding.

Key design decisions: Point out anything that is non-obvious or that a reader might initially get wrong. Explain any patterns, abstractions, or constraints that shaped the implementation. If the code works around a bug or a framework quirk, say so.

Dependencies and callers: What does this code depend on, and what depends on it? Name the two or three most important relationships.

What to know before modifying it: Gotchas, invariants, or side effects a developer must not break. What tests cover it? What is likely to break if the signature or behavior changes?

Read the full file on GitHub · 56 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. yesterday First seen · 56 lines · 86 tokens per session scan A f6d82c2fddb2

Subscribe to this mod's changes

explain-code is a command published in the GitHub repository KhaledSaeed18/dotclaude (4 stars, last pushed 7d ago), licensed MIT. It adds 86 tokens to every session and 657 once invoked, about $0.0004 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 2026-08-31.