Gemini CLI is a terminal-based AI agent that lets developers interact with Google Gemini models and use tools for tasks such as file operations, shell commands, web fetching, and search. Developers use it from the command line, and the catalogue add-ons extend its workflows and integrations.
Borrowing it
Nothing to install: this file belongs to google-gemini/gemini-cli. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/google-gemini/gemini-cli/main/.gemini/skills/review-duplication/SKILL.mdgit clone --depth 1 https://github.com/google-gemini/gemini-cliWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/google-gemini/gemini-cli/review-duplication)<a href="https://agentmods.dev/skills/google-gemini/gemini-cli/review-duplication"><img src="https://agentmods.dev/badge/skills/google-gemini/gemini-cli/review-duplication/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/google-gemini/gemini-cli/review-duplication"><img src="https://agentmods.dev/badge/skills/google-gemini/gemini-cli/review-duplication.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk pass
- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00037 | $0.01165 |
| Opus 5.5 | $0.00015 | $0.00466 |
| Sonnet 5.5 | $0.00007 | $0.00233 |
| Haiku 4.5 | $0.00004 | $0.00117 |
Grade A, and why
review-duplication 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 1mo 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- review-duplication — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Review Duplication
Overview
This skill provides a structured workflow for investigating a codebase during a code review to identify duplicated logic, reinvented utilities, and missed opportunities to reuse established patterns. By executing this workflow, you ensure that new code integrates seamlessly with the existing project architecture.
Workflow: Investigating for Duplication
When reviewing code, perform the following steps before finalizing your review:
1. Extract Core Logic
Analyze the new code to identify the core algorithms, utility functions, generic data structures, or UI components being introduced. Look beyond the specific business logic to see the underlying mechanics.
2. Hypothesize Existing Locations & Trace Dependencies
Think about where this type of code would live if it already existed in the project. Provide absolute paths from the repo root to disambiguate.
- Utilities:
packages/core/src/utils/,packages/cli/src/utils/ - UI Components:
packages/cli/src/ui/components/,packages/cli/src/ui/ - Services:
packages/core/src/services/,packages/cli/src/services/ - Configuration:
packages/core/src/config/,packages/cli/src/config/ - Core Logic: Call out
packages/core/if functionality does not appear React UI specific.
Trace Third-Party Dependencies: If the PR introduces a new import for a utility library (e.g., lodash.merge, date-fns), trace how and where the project currently uses that library. There is likely an existing wrapper or shared utility.
Check Package Files: Before flagging a custom implementation of a complex algorithm, check package.json to see if a standard library (like lodash or uuid) is already installed that provides this functionality.
3. Investigate the Codebase (Sub-Agent Delegation)
Delegate the heavy lifting of codebase investigation to specialized sub-agents. They are optimized to perform deep searches and semantic mapping without bloating your session history.
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.
- 1mo ago First seen · 70 lines · 37 tokens per session scan A 79952fb123e4
review-duplication is a skill published in the GitHub repository google-gemini/gemini-cli (107,525 stars, last pushed today), licensed Apache-2.0. It adds 37 tokens to every session and 1,165 once invoked, about $0.0001 per session on Opus 5.5. 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.
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