Gemini Sub-Agent

Use Google Gemini as a free sub-agent via a Google One / Gemini Advanced subscription (no API key or API credits needed). Use when: (1) delegating tasks that would normally cost Sonnet/Haiku credits, (2) processing large documents or long-context tasks (1M token window), (3) running agentic coding tasks autonomously, (4) any text analysis, summarization, or Q&A task. Replaces paid cloud models for medium-complexity tasks. NOT for: tasks needing OpenClaw-native tools (web_search, sessions_spawn, Telegram), real-time data, or tasks requiring OpenClaw context.

Use Google Gemini (via subscription, $0 API cost) as a sub-agent inside OpenClaw workflows.

Setup

Run once on a fresh machine:

bash

bash skills/gemini-sub-agent/scripts/setup.sh

Then authenticate (headless VPS flow):

1. On VPS: gcloud auth application-default login --no-browser → copy the --remote-bootstrap URL
2. On laptop: gcloud auth application-default login --remote-bootstrap="<URL>" → copy the localhost:8085 output
3. Paste localhost:8085 output back into VPS prompt
4. Complete Gemini CLI OAuth: GOOGLE_GENAI_USE_GCA=true gemini -p "hello" → paste auth code

Credentials are cached indefinitely and auto-refresh.

Available Models

Model	Use for
gemini-3.1-pro-preview	Default — latest flagship, best reasoning
gemini-2.5-pro	Stable coding tasks, multi-file edits
gemini-3-flash-preview	Fast summaries, quick Q&A
gemini-3-pro-preview	Previous gen Pro, reliable fallback
gemini-2.5-flash	Lightweight fallback

Usage Patterns

1. Simple text task (exec)

bash

ask-gemini "your prompt here"
ask-gemini -m gemini-2.5-pro "your prompt"

2. Pipe large content (long-context)

bash

cat large_file.txt | ask-gemini "summarize this in 5 bullets"
cat report.md | ask-gemini "extract all action items"

3. Agentic coding (replaces Swift/Sonnet for 30-200 line tasks)

bash

cd /path/to/project
GOOGLE_GENAI_USE_GCA=true gemini -m gemini-2.5-pro -y -p "write a script that..."

-y = yolo mode (auto-approves all file writes and shell commands). Gemini reads/writes files autonomously.

4. Pipe files directly into agentic session

bash

cat existing_script.py | GOOGLE_GENAI_USE_GCA=true gemini -m gemini-2.5-pro -y -p "refactor this to add error handling"

Routing Rules (when to use Gemini vs others)

Task	Use
Text, analysis, summarization	ask-gemini
Medium coding (30–200 lines)	Gemini agentic (-y) instead of Swift/Sonnet
Large file / long-context	ask-gemini (1M token window)
Web search / research	Research agent (Grok) — Gemini has no web access
Multi-agent orchestration	OpenClaw native (sessions_spawn)
Complex architecture / debugging	Codex (Opus) — escalate if Gemini fails twice

Escalation

If Gemini returns wrong output twice on the same task → escalate to Swift (Sonnet) or Codex (Opus). Log the failure in failures/hot_antipatterns.md with the task type.

Scripts

• scripts/setup.sh — Full install: gemini-cli + gcloud + ask-gemini wrapper
• scripts/ask-gemini — The wrapper script itself (copy to /usr/local/bin/)