Google has released as open source a plugin for coding agents that it developed internally, the Korean outlet AI Times reported on 9 November. Thousands of Google engineers use it in product development, AI Times said.

The plugin is called Elephant-Goldfish Model (EGM) and is licensed under Apache 2.0. A description and installation instructions are in Google’s GitHub repository, which states that EGM is not an officially supported Google product.

The elephant plans, the goldfish review

The Elephant is a session that knows the project, its requirements and earlier decisions. It works through the problem with the user and writes a plan: a software specification document. The Elephant does not write code, AI Times reported.

The Goldfish are subagents that receive the plan and the source material it references, but not the earlier conversation. The repository says this helps expose blind spots and unstated assumptions. AI Times gave the rationale: when the same AI both plans and reviews, it can accept its own flawed initial assumptions.

The review has five stages. The reviewers assess the plan’s design decisions, clarity, fit with existing code and implementation plan, among other things, the repository says. The user decides which findings to fix. After approving the plan, the user asks the coding agent to implement it.

The plugin also has dedicated functions for brainstorming, working through review findings and documenting existing code. Users can compare documents stored in the repository with the current source code using the Drift report function.

No published measurements of the benefit

No benchmarks have been published showing that EGM improves accuracy, AI Times reported. The repository says the review does not replace tests or human judgement. The ready-made workflow is designed for software specifications. To review other documents, users choose the reviewers and standards themselves.

Runs inside an existing agent

EGM is not a model but a plugin for a harness: the program that steers an agent, gives the model its tools and runs its steps. EGM uses the user’s existing large language model and counts against the user’s usage limit, AI Times reported.

The Goldfish review requires a harness that can create new subagents without prior context. Without one, EGM stops the review. The repository includes installation instructions for Claude Code, Codex CLI, Antigravity and the ChatGPT and Codex desktop apps, among others.