Elephant-Goldfish Model from Google

Elephant-Goldfish Model is an open-source framework and methodology for Spec-Driven Development (SDD) with autonomous AI coding agents.

It anchors development in context-rich system descriptions and adversarial multi-agent reviews, making complex codebases easier for both humans and AI to navigate, verify, and evolve.

EGM uses two animal metaphors to describe how to prompt, constrain, and structure AI agents at different stages of the software development lifecycle:

For the foundational essay introducing this methodology, see Dave Rensin's article: Elephants, Goldfish, and the New Golden Age of Software Engineering.

├── agents/ # Stateless reviewer and orchestrator persona prompts ├── docs/ # Documentation, guides, and FAQ │ └── designs/ # Living technical design specifications ├── resources/ │ └── document_standards/ # Quality evaluation rubrics and standards ├── skills/ # Modular agent skills (Brainstorm, Draft, Review, etc.) └── tests/ └── evals/ # Automated YAML evaluation benchmarks

Skills

Skill Command Description

Brainstorm /egm-brainstorm Zero-doc ideation tool using a multi-lens Goldfish shootdown swarm to stress-test early concepts.

Draft /egm-draft Iterative, section-by-section markdown design specification compiler.

Review /egm-review Multi-stage verification pipeline orchestrator (Zoom Out → Comprehension → Critic → Readiness).

Review Loop /egm-review-loop Concurrent review subagent dispatch engine supporting direct and hierarchical dispatch.

Review Resolve /egm-resolve Interactive triage and automated patch application engine for review findings.

Drift Report /egm-drift-report Sequential AST scanner detecting divergence between checked-in specs and live code.

Bootstrap /egm-bootstrap Recursive bottom-up codebase documentation generator and sentinel-block upserting engine.

Quickstart

Ideate & Stress-Test: Run /egm-brainstorm to explore problem boundaries and subject raw concepts to a multi-lens Goldfish shootdown swarm.

Draft: Run /egm-draft to convert the egm-brainstorm output (a concept brief) into a living design document under docs/designs/<feature>.md (or user designated directory).

Review & Resolve: Run /egm-review docs/designs/<feature>.md to launch the multi-stage Goldfish reviewer swarm on the design document produced by egm-draft (interactive resolution via /egm-resolve is integrated directly into the review loop).

Submit & Implement: Submit the verified design doc via Pull Request, and implement code against the approved specification.

For detailed setup, supported harnesses (Antigravity and Gemini CLI), and walkthroughs, see Getting Started, Harnesses, and the Framework Architecture.

We welcome community contributions! Please review Harnesses and our Contribution Guidelines before submitting pull requests.

This project is licensed under the Apache 2.0 License - see the LICENSE file for details.

This is not an officially supported Google product.