Google Gemini Integration¶

One pip install shekel[gemini] and one with budget(): — shekel intercepts every Gemini call, enforces hard spend limits, and shows you exactly what was spent. All the same budget controls (hard caps, fallback models, nested budgets, BudgetExceededError) work identically to OpenAI and Anthropic.

Installation¶

pip install shekel[gemini]

Why a dedicated adapter?¶

Unlike OpenAI and Anthropic, Gemini uses its own SDK (google-genai) that makes direct API calls — it does not route through the OpenAI SDK. Without a dedicated adapter, budget() would be completely blind to Gemini spend.

Shekel's GeminiAdapter patches two methods at runtime:

google.genai.models.Models.generate_content — non-streaming calls
google.genai.models.Models.generate_content_stream — streaming calls

All other Shekel features (nested budgets, fallback models, BudgetExceededError) work identically.

Basic Integration¶

import google.genai as genai
from shekel import budget

client = genai.Client(api_key="your-gemini-key")

with budget(max_usd=1.00) as b:
    response = client.models.generate_content(
        model="gemini-2.0-flash-lite",
        contents="Explain quantum computing in one sentence.",
    )
    print(response.candidates[0].content.parts[0].text)
    print(f"Cost: ${b.spent:.6f}")

Streaming¶

Gemini streaming uses a separate method (generate_content_stream) rather than a stream=True kwarg — Shekel patches both:

with budget(max_usd=1.00) as b:
    for chunk in client.models.generate_content_stream(
        model="gemini-2.0-flash-lite",
        contents="List three benefits of Python.",
    ):
        if chunk.candidates:
            print(chunk.candidates[0].content.parts[0].text, end="", flush=True)
    print()
    print(f"Cost: ${b.spent:.6f}")

Nested Budgets¶

Track costs across multi-step Gemini workflows:

with budget(max_usd=5.00, name="pipeline") as total:
    with budget(max_usd=1.00, name="research") as research:
        client.models.generate_content(
            model="gemini-2.0-flash-lite",
            contents="Summarise recent AI trends.",
        )

    with budget(max_usd=2.00, name="analysis") as analysis:
        client.models.generate_content(
            model="gemini-2.0-flash",
            contents="Analyse the implications of those trends.",
        )

print(f"Research: ${research.spent:.6f}")
print(f"Analysis: ${analysis.spent:.6f}")
print(f"Total:    ${total.spent:.6f}")
print(total.tree())

Fallback Models¶

Switch to a cheaper Gemini model when spend reaches a threshold:

with budget(
    max_usd=0.50,
    fallback={"at_pct": 0.8, "model": "gemini-2.0-flash-lite"},
) as b:
    # Starts with gemini-2.0-flash; auto-switches at 80% ($0.40)
    response = client.models.generate_content(
        model="gemini-2.0-flash",
        contents="Write a detailed market analysis.",
    )

if b.model_switched:
    print(f"Switched to fallback at ${b.switched_at_usd:.4f}")

Same-provider fallback only

Fallback must be another Gemini model. Cross-provider fallback (e.g. Gemini → GPT-4o) is not supported.

Budget Enforcement¶

Stop a runaway Gemini loop automatically:

from shekel import BudgetExceededError

try:
    with budget(max_usd=2.00) as b:
        for _ in range(100):  # Shekel stops this when budget runs out
            client.models.generate_content(
                model="gemini-2.0-flash-lite",
                contents="Analyse this document.",
            )
except BudgetExceededError as e:
    print(f"Stopped at ${e.spent:.4f} — saved the rest of the budget.")

Supported Models and Pricing¶

Model	Input (per 1k tokens)	Output (per 1k tokens)
`gemini-2.5-pro`	$0.00125	$0.01000
`gemini-2.5-flash`	$0.000075	$0.00030
`gemini-2.0-flash`	$0.000075	$0.00030
`gemini-2.0-flash-lite`	$0.000075	$0.00030
`gemini-1.5-pro`	$0.00125	$0.00500
`gemini-1.5-flash`	$0.000075	$0.00030

Shekel uses prefix matching, so gemini-2.0-flash-001 and similar versioned names resolve automatically.

Custom Pricing¶

For models not in the pricing table, pass price_per_1k_tokens:

with budget(
    max_usd=1.00,
    price_per_1k_tokens={"input": 0.0001, "output": 0.0003},
) as b:
    client.models.generate_content(
        model="gemini-3-flash-preview",
        contents="Hello.",
    )

Tips for Gemini + Shekel¶

Use generate_content_stream for long responses — streaming lets you stop mid-generation if the budget is hit
Wrap at the workflow level, not per-call, for accurate total cost tracking
Set warn_at=0.8 to log a warning before the budget cap triggers
Gemini free tier has per-minute limits — use exponential backoff for production workloads