explain

A command for explaining Go source code, from an individual function or file to a whole package, with diagrams for complex flows.

In plain words
What is it for?
Use it to understand Go files, functions, or packages and to produce documentation-style explanations with Mermaid diagrams when useful.
Why use it?
It turns unfamiliar Go code into a structured explanation by describing its concepts, interfaces, dependencies, patterns, and execution flow.

Command

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/gopherguides/gopher-ai/explain
Clone the repo
git clone --depth 1 https://github.com/gopherguides/gopher-ai
Per session 9 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,703 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 $0.00009 $0.01703
Opus 5 $0.00005 $0.00851
Sonnet 5 $0.00002 $0.00341
Haiku 4.5 $0.00001 $0.00170

Measured 2d ago against content hash 02c8f9bc19f4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

explain 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 2d ago.

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.

plugins/go-dev/commands/explain.md · 246 lines

How it starts

The opening of the file, as written. The whole thing — 246 lines — stays where its author put it; the contents beside it link to each section on GitHub.

If $ARGUMENTS is empty or not provided:

Display usage information and ask for input:

Usage: /explain <target>

Examples:

  • /explain pkg/auth/login.go - Explain a file
  • /explain HandleAuthentication - Explain a function
  • /explain pkg/services/ - Explain a package

Workflow:

  1. Analyze the specified Go code target
  2. Extract key concepts, interfaces, dependencies
  3. Generate documentation-style explanation
  4. Create Mermaid diagrams for complex flows
  5. Identify idiomatic Go patterns used

Ask the user: "What file, function, or package would you like me to explain?"


If $ARGUMENTS is provided:

Generate a comprehensive explanation of the specified Go code. Creates documentation-style output with Mermaid diagrams for complex flows.

Configuration

  • Target: $ARGUMENTS (file path, function name, or package)

Context Management

Before loading file content:

  1. Check size first: Use Glob to find the file, note its size
  2. For files >300 lines:
    • Read first 50 lines (package, imports, type declarations)
    • Use Grep to find specific function/type definitions
    • Read only the relevant sections
    • Do NOT load entire file into context
  3. For packages with >20 files:
    • List files first with Glob
    • Read doc.go if present
    • Sample 2-3 representative files maximum

Steps

  1. Identify Target Scope

    • If file path: Check file size before reading
    • If function name: Search for the function across packages
    • If package: Analyze the package structure
  2. Analyze Go Code Structure

    For files, extract:

    • Package and purpose
    • Exported vs unexported identifiers
    • Types and interfaces defined
    • Key functions and methods
    • Dependencies (imports)

    For functions, extract:

    • Signature (receiver, params, returns)
    • Error handling patterns
    • Goroutine usage
    • Channel operations
    • Context handling

    For packages, extract:

    • Package purpose and API surface
    • Public interfaces
    • Internal organization
    • Dependencies on other packages

Read the full file on GitHub · 246 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. 2d ago First seen · 246 lines · 9 tokens per session scan A 02c8f9bc19f4

Subscribe to this mod's changes

explain is a command published in the GitHub repository gopherguides/gopher-ai (21 stars, last pushed 2d ago), licensed MIT. It adds 9 tokens to every session and 1,703 once invoked, about $0.0000 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 2026-08-30.