Gemini CLI Extensions

What's in this pack

This pack mirrors the ten official extensions Google publishes for Gemini CLI on the google-gemini/gemini-cli GitHub repo. Every entry is a first-party Google release — no community forks, no half-maintained mirrors. If Google deprecates one upstream, we follow within a release cycle.

Why Gemini CLI extensions matter

Gemini CLI's killer feature is its 1M-token context — but raw context is useless without typed surfaces to call. Extensions are how Gemini CLI gets typed: each one declares tools, schemas, and credential paths so the agent isn't guessing how to call your warehouse or your Figma file. They are Google's answer to the Claude Code subagent layer and the MCP server layer at once: tighter than MCP because they ship with Gemini-specific UX, lighter than subagents because they don't need a separate prompt.

The five anchors most teams actually use day-to-day:

• Stitch is the most-demoed of the lot. Drop a Figma URL or a screenshot, and Gemini emits production-ready React/Vue/Tailwind. The output is a real PR, not a Storybook prop.
• Workspace lets you generate a doc, fill a sheet, or edit slides from terminal. Useful for status reports and meeting prep.
• Code Review runs a structured review pass against a diff or a branch — comments grouped by severity, with file/line anchors.
• Postgres opens a connection pool, runs read-only queries by default, and lets the agent introspect schema before composing SQL.
• Vertex AI matters when you cannot send code or data to the public Gemini endpoint. Routing through Vertex keeps everything inside your GCP project, your IAM, your audit logs.

Install in one command

# Install the entire pack
tokrepo install pack/gemini-cli-extensions

# Or pick a single extension
tokrepo install gemini-stitch
tokrepo install gemini-vertex-ai

The TokRepo CLI writes the right entries into ~/.gemini/extensions.json and registers each extension's manifest. No editing JSON by hand, no chasing the install order from blog posts. Run tokrepo uninstall <slug> to remove cleanly.

Common pitfalls

• Auth scope drift. Workspace and Vertex AI need different OAuth scopes. Install them in the same shell session with gcloud auth login --update-adc already current; otherwise the second install will silently fall back to the first's scopes and fail at first call.
• Stitch Figma rate limits. Free Figma tier limits API calls per minute. Batch large pages or you'll see partial component sets and have to retry.
• Postgres extension is read-only by default. Mutations require explicit --allow-write. This is a feature: it stops accidental DROP TABLE prompts. Enable per-session, never globally.
• Vertex AI billing surprise. Routing through Vertex turns every Gemini call into a billed API request on your GCP project, even if you previously had quota on the public endpoint. Set a budget alert before installing.
• Search Grounding is region-locked. A few extensions return empty grounding chunks in EU regions due to consent flags. Check the per-extension support matrix on the upstream repo before relying on grounding for compliance flows.

Relationship to other packs

This pack is the Gemini CLI side of a three-pack story: Gemini CLI extensions here, Claude Code subagents in claude-code-subagents, and cross-tool MCP servers in mcp-server-stack. If you live in Gemini CLI, install this. If you switch tools weekly, install MCP servers instead — they survive the transition. Teams that ship across Gemini CLI and Claude Code in the same week typically install all three packs and let each agent pick the surface it understands best.