Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents
by Google
An Apache 2.0 plugin and guide for drafting a design doc with a context-rich agent, then having zero-context subagents attack it before any code is written.
Overview
The Elephant-Goldfish Model (EGM) is an Apache 2.0 repository from Google, created on September 13, 2026, with 10,782 GitHub stars and a push on November 3, 2026 when checked that day. Its README calls it not an officially supported Google product and says thousands of Google engineers use it. The ideas come from Dave Rensin's essay "Elephants, Goldfish and the New Golden Age of Software Engineering." The elephant is an agent with project context that drafts the specification. Goldfish are reviewers that get the document and its sources without the earlier conversation. The material ships seven skills: brainstorm, draft, resolve, bootstrap, review, review loop and drift report. Brainstorm runs a six-lens goldfish swarm and writes concepts_brief.md. Draft produces a design document one section at a time. Review runs a zoom-out pass, a comprehension test, a critic review, a second zoom-out and an implementation-readiness test. The docs cover install for Antigravity, Claude Code and Codex, with setup guides for Claude Cowork and ChatGPT Work. Claude reviewers are limited to Read, Grep and Glob, and Claude Code 2.1.271 or later is required for verified isolation, which the docs describe as context and tool isolation, with no filesystem sandbox. The project writes no code itself and recommends your normal workflow for small, clear bug fixes.
At a Glance
- Topic
- Skills
- Level
- Intermediate
- Format
- Documentation
- Cost
- Free
- Duration
- Self-paced; no published time estimate, so plan on one real feature design from brainstorm to review
- Provider
- Hands-on
- Yes — code/exercises
- Certificate
- None
What You’ll Learn
- ✓Run a brainstorm that stress-tests a feature idea through six independent goldfish review lenses
- ✓Turn a concept brief into a design document, reviewing each section before the next is drafted
- ✓Run staged zoom-out, comprehension, critic and implementation-readiness reviews against a design draft in fresh contexts
- ✓Work through review findings and decide which ones actually change the design before implementation
- ✓Bootstrap READMEs for an existing codebase from leaf directories up to the root, with human review
- ✓Use a drift report to compare checked-in design documents against the current source code
- ✓Configure read permissions for headless Claude Code runs without disabling permission checks or granting every plugin access
Highlights
- •The architecture doc documents the personas, stage standards and fan-out synthesizer, so you can copy the pattern without adopting the whole plugin
- •The Claude setup guide states where isolation stops: reviewers can read any file they have permission to access, and plugin subagents ignore hooks and permissionMode
- •A University of Maryland course teaches the underlying model in a full lecture chapter (CMSC 389A, Fall 2026)
- •The review stops if the host agent cannot create isolated subagents, so a same-session run cannot pass as a goldfish review
- •MindStudio's October 30, 2026 write-up warns that five or six fresh subagents cost noticeably more tokens than direct implementation, and that reviews produce more feedback than you will act on
Who It’s For
Best For
- ✓Engineers using Claude Code, Codex or Antigravity on features large enough to need a written design
- ✓Tech leads who want agent-written design documents reviewed before human review and implementation
- ✓Agent developers studying how to structure isolated, role-based reviewer subagents and their output files
Prerequisites
- •Working experience with a coding agent host such as Claude Code, Codex or Antigravity CLI
- •A host that can create fresh subagents; Claude Code needs version 2.1.271 or later for verified isolation
- •Enough software design experience to judge which review findings to accept and which to discard
FAQ
What is Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents?
The Elephant-Goldfish Model is an open-source skills plugin and documentation set for engineers who design features with AI coding agents. After working through it, you can take an idea through brainstorm, design draft and isolated multi-stage review, then detect drift between the approved design and the code.
Is Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents free?
Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents is free to access.
What level is Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents for?
Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents is aimed at a intermediate audience. Recommended background: Working experience with a coding agent host such as Claude Code, Codex or Antigravity CLI, A host that can create fresh subagents; Claude Code needs version 2.1.271 or later for verified isolation, Enough software design experience to judge which review findings to accept and which to discard.
How long does Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents take?
Expect roughly Self-paced; no published time estimate, so plan on one real feature design from brainstorm to review. Most learners work through it at their own pace.
What will I learn from Elephant-Goldfish Model (EGM): Design and Review Skills for AI Coding Agents?
You'll learn: Run a brainstorm that stress-tests a feature idea through six independent goldfish review lenses; Turn a concept brief into a design document, reviewing each section before the next is drafted; Run staged zoom-out, comprehension, critic and implementation-readiness reviews against a design draft in fresh contexts; Work through review findings and decide which ones actually change the design before implementation; Bootstrap READMEs for an existing codebase from leaf directories up to the root, with human review; Use a drift report to compare checked-in design documents against the current source code; Configure read permissions for headless Claude Code runs without disabling permission checks or granting every plugin access.
Topics
Sources
This page was written from 7 sources, 6 on domains other than egm.dev.