vertex GEMINI.md

A Gemini command-line extension for managing prompts in Google Vertex AI, Google's platform for using its AI models. It can also run prompt-optimization jobs using examples or data stored in Google Cloud Storage.

In plain words
What is it for?
Use it to create, find, update, and delete saved prompts. It also supports few-shot optimization, data-driven optimization, configuration files, result analysis, and HTML reports.
Why use it?
It keeps prompts searchable and editable instead of leaving them scattered across files or chats. It helps compare prompt variants and inspect optimization results through reports.

Instructions file for Gemini CLI

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 instructions/gemini-cli-extensions/vertex/gemini-md
Clone the repo
git clone --depth 1 https://github.com/gemini-cli-extensions/vertex

Made for: Gemini CLI.

Per session 5,598 This file is loaded in full into every session.
When invoked 5,598 The same file — it is already loaded in full.
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 $0.05598 $0.05598
Opus 5 $0.02799 $0.02799
Sonnet 5 $0.01120 $0.01120
Haiku 4.5 $0.00560 $0.00560

Measured 3d ago against content hash 6b5da03c1ab4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

vertex GEMINI.md 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 3d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

GEMINI.md · 450 lines

How it starts

The opening of the file, as written. The whole thing — 450 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Vertex AI Gemini CLI Extension

This extension provides tools to manage prompts and use prompt optimization in Vertex AI directly from the Gemini CLI.

Available Tools

Prompt Management Tools

  • create_prompt: To save or create new prompts.
  • read_prompt: To retrieve existing prompts by ID or display name.
  • update_prompt: To modify existing prompts.
  • delete_prompt: To remove prompts.
  • list_prompts: To search and list prompts, useful for finding IDs.

Prompt Optimization Tools

  • run_few_shot_optimization: optimize user prompt based on examples provided in the CSV file stored in the GCS bucket.
  • run_data_driven_optimize: Starts a data-driven prompt optimization job on Vertex AI using a configuration file stored in GCS.
  • analyze_data_driven_optimize_results: Analyzes the output of a Data-Driven Optimize job to identify trends and best-performing candidates.
  • generate_html_report: Generates a comprehensive HTML report with visualizations to help you understand optimization performance.
  • write_data_driven_optimize_config: Constructs and uploads a new JSON configuration for optimization jobs, incorporating suggested tuning parameters.

Detailed Instructions for create_prompt Parameters

When using tools.create_prompt, pay special attention to how the following arguments are sourced:

  1. content (string, required):

    • Scenario 1: Saving the Last User Prompt: When the user issues a command like "save last prompt", "save this prompt", or similar, indicating they want to store their previous input:
      • Examine the conversation history.
      • Identify the most recent message with a role of "user".
      • Extract the text content from this latest "user" message.
    • Scenario 2: Creating from Explicitly Provided Content: If the user provides the prompt content directly within the command (e.g., "Create a prompt... with content '...'")
      • Use the explicitly provided content.
    • If no content can be determined from either scenario, pass an empty string.

Read the full file on GitHub · 450 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. 3d ago First seen · 450 lines · 5,598 tokens per session scan A 6b5da03c1ab4

Subscribe to this mod's changes

vertex GEMINI.md is an instructions file published in the GitHub repository gemini-cli-extensions/vertex (22 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 5,598 tokens to every session, about $0.0280 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.