Skip to main content

Documentation Index

Fetch the complete documentation index at: https://docs.benchspan.com/llms.txt

Use this file to discover all available pages before exploring further.

The Google Agent Development Kit (ADK) exposes a before_model_callback / beforeModelCallback hook that fires before every LLM call. Benchspan ships a factory that scans each content part before the Gemini call goes out.

​
Python

1

Install

pip install benchspan google-adk
2

Register the callback

agent.py
from benchspan import BenchGuard
from google.adk import LlmAgent

guard = BenchGuard(api_key="ag_live_...", agent="gemini-app")

agent = LlmAgent(
    name="assistant",
    model="gemini-2.5-pro",
    before_model_callback=guard.as_adk_callback(),
)

​
TypeScript

1

Install

npm install @benchspan/sdk @google/adk
2

Register the callback

agent.ts
import { BenchGuard } from "@benchspan/sdk";
import { LlmAgent } from "@google/adk";

const guard = new BenchGuard({ apiKey: "ag_live_...", agent: "gemini-app" });

const agent = new LlmAgent({
  name: "assistant",
  model: "gemini-2.5-pro",
  beforeModelCallback: guard.asAdkCallback(),
});

​
What gets scanned

Every text part in llmRequest.contents. The role of each content determines how it’s classified:
ADK roleScanned as
useruser
model (tool response round-trips)tool
System instructions and pure model completions are skipped; they’re inside your trust boundary.

​
Handling blocks

In block mode, the callback raises InjectionDetectedError which propagates out of the ADK invocation. Wrap your agent call in a try / except (Python) or try / catch (TypeScript): 
from benchspan import InjectionDetectedError

try:
    response = await agent.run_async(user_input)
except InjectionDetectedError as e:
    # Log, alert, return safe error to user
    print(f"Blocked: score={e.result.score:.4f}")