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Google’s Gemini models work in Swarms through the same Agent interface as every other provider. Gemini’s massive context windows (up to 2M tokens) and strong multimodal support make it a natural fit for long-document analysis, video understanding, and image-heavy workflows.

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Installation

pip install -U swarms

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Environment Setup

export GEMINI_API_KEY="..."
Or in a .env file: 
GEMINI_API_KEY="..."
WORKSPACE_DIR="agent_workspace"
Get your API key at aistudio.google.com. The free tier is generous and great for prototyping.

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Quick Start

The minimum needed to run a Gemini agent: 
from swarms import Agent

agent = Agent(
    agent_name="Gemini-Agent",
    model_name="gemini/gemini-2.5-pro",
    max_loops=1,
)

print(agent.run("Summarize the difference between RAG and fine-tuning in three paragraphs."))

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Model Names

Gemini models are prefixed with gemini/ for LiteLLM routing:
Modelmodel_nameBest for
Gemini 2.5 Pro"gemini/gemini-2.5-pro"Frontier reasoning, long-document analysis, 2M context
Gemini 2.5 Flash"gemini/gemini-2.5-flash"Balanced speed + quality, default for production
Gemini 2.5 Flash-Lite"gemini/gemini-2.5-flash-lite"High-volume triage, lowest cost
Gemini 2.0 Flash"gemini/gemini-2.0-flash"Legacy production workloads

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Gemini 2.5 Pro — Frontier Reasoning

The right pick for hard reasoning tasks, long-document analysis, or anything where you need the full 2M-token context window. 
from swarms import Agent

agent = Agent(
    agent_name="Gemini-Pro-Researcher",
    model_name="gemini/gemini-2.5-pro",
    system_prompt="You are a senior research analyst. Cite evidence and reason carefully.",
    context_length=1_000_000,
    max_loops=1,
)

print(agent.run("Walk me through the architectural choices behind Gemini 2.5's mixture-of-experts design."))

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Gemini 2.5 Flash — The Workhorse

Flash is the right default for most production agents. Strong quality, fast, and cheap. 
from swarms import Agent

def get_weather(city: str) -> str:
    """Return the current weather for a city."""
    return f"{city}: 21°C, partly cloudy"

agent = Agent(
    agent_name="Gemini-Flash-Assistant",
    model_name="gemini/gemini-2.5-flash",
    tools=[get_weather],
    temperature=0.5,
    max_loops=3,
)

print(agent.run("What's the weather in Tokyo right now?"))

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Gemini 2.5 Flash-Lite — Triage & High-Volume

For classification, routing, and high-volume workloads where cost matters most. 
from swarms import Agent

agent = Agent(
    agent_name="Gemini-Triage",
    model_name="gemini/gemini-2.5-flash-lite",
    system_prompt="Classify each input as one of: support, sales, billing, other. Reply with the label only.",
    max_loops=1,
)

print(agent.run("My subscription renewed but I was charged twice."))

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Vision

Gemini’s vision capabilities are excellent. Pass an image path, URL, or base64 string: 
from swarms import Agent

agent = Agent(
    agent_name="Gemini-Vision",
    model_name="gemini/gemini-2.5-pro",
    max_loops=1,
)

result = agent.run(
    task="Describe what's in this image and identify any text you see.",
    img="path/to/screenshot.png",
)
print(result)

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Long-Context Document Analysis

Gemini 2.5 Pro’s massive context window lets you drop entire books, codebases, or document sets into a single prompt: 
from swarms import Agent

# Load a large document
with open("annual_report.pdf.txt") as f:
    document = f.read()

agent = Agent(
    agent_name="Document-Analyst",
    model_name="gemini/gemini-2.5-pro",
    context_length=2_000_000,
    max_loops=1,
)

print(agent.run(
    f"Here is our annual report. Identify the top three financial risks and quote the relevant sections.\n\n{document}"
))

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Streaming

Stream tokens straight to stdout: 
from swarms import Agent

agent = Agent(
    agent_name="Streaming-Gemini",
    model_name="gemini/gemini-2.5-flash",
    streaming_on=True,
    max_loops=1,
)

agent.run("Write a 200-word explanation of how attention works in transformers.")
Or pipe tokens through your own callback: 
def on_token(token: str) -> None:
    print(token, end="", flush=True)

agent = Agent(
    agent_name="Callback-Gemini",
    model_name="gemini/gemini-2.5-flash",
    streaming_callback=on_token,
    max_loops=1,
)

agent.run("Explain WebAssembly to a backend engineer.")

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Tool Use

Gemini handles tool calls fluently. Define plain Python functions with docstrings: 
import yfinance as yf
from swarms import Agent

def get_stock_price(ticker: str) -> str:
    """Fetch the current stock price for a given ticker symbol."""
    data = yf.Ticker(ticker)
    return f"{ticker}: ${data.fast_info['last_price']:.2f}"

def get_market_cap(ticker: str) -> str:
    """Fetch the market capitalization for a given ticker."""
    data = yf.Ticker(ticker)
    cap = data.fast_info.get("market_cap")
    return f"{ticker} cap: ${cap:,.0f}" if cap else f"{ticker}: unavailable"

agent = Agent(
    agent_name="Equity-Researcher",
    model_name="gemini/gemini-2.5-flash",
    tools=[get_stock_price, get_market_cap],
    max_loops=3,
)

print(agent.run("Compare NVDA, AMD, and INTC on price and market cap."))

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Mixing Models in a Workflow

Different Gemini models for different jobs in the same workflow: 
from swarms import Agent, SequentialWorkflow

triage = Agent(
    agent_name="Triage",
    model_name="gemini/gemini-2.5-flash-lite",     # cheap & fast
    system_prompt="Classify and route the user request.",
    max_loops=1,
)

researcher = Agent(
    agent_name="Researcher",
    model_name="gemini/gemini-2.5-flash",          # balanced
    system_prompt="Gather all relevant context and data.",
    max_loops=2,
)

analyst = Agent(
    agent_name="Analyst",
    model_name="gemini/gemini-2.5-pro",            # frontier
    system_prompt="Reason carefully and produce the final analysis.",
    context_length=1_000_000,
    max_loops=1,
)

pipeline = SequentialWorkflow(agents=[triage, researcher, analyst], max_loops=1)
print(pipeline.run("Evaluate whether we should self-host Llama 3.3 or stay on managed APIs."))

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Production Defaults

For Gemini agents in production: 
from swarms import Agent

agent = Agent(
    agent_name="Production-Gemini",
    model_name="gemini/gemini-2.5-flash",
    max_loops=1,
    persistent_memory=True,        # survive process restarts
    context_compression=True,      # auto-summarize at 90% of context
    context_length=1_000_000,
    autosave=True,
    retry_attempts=3,
    print_on=False,
)

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Next Steps