Anthropic SDK (raw)

The Anthropic SDK doesn’t have lifecycle hooks, so Benchspan wraps your Claude call with a decorator (Python) or wrapCall helper (TypeScript). Every user and tool message is scanned before the request goes out.

Python

Install

pip install benchspan anthropic

Decorate the call

claude.py

from benchspan import BenchGuard, InjectionDetectedError
from anthropic import Anthropic

guard = BenchGuard(api_key="ag_live_...", agent="claude-app")
client = Anthropic()

@guard.wrap
def ask_claude(messages):
    return client.messages.create(
        model="claude-sonnet-4-6",
        max_tokens=1024,
        messages=messages,
    )

try:
    response = ask_claude(messages)
except InjectionDetectedError as e:
    print(f"Blocked: {e.result.verdict}, score={e.result.score:.4f}")

Use @guard.wrap_async for an async def function.

TypeScript

Install

npm install @benchspan/sdk @anthropic-ai/sdk

Wrap the call

claude.ts

import { BenchGuard, InjectionDetectedError } from "@benchspan/sdk";
import Anthropic from "@anthropic-ai/sdk";

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

try {
  const response = await guard.wrapCall(messages, () =>
    client.messages.create({
      model: "claude-sonnet-4-6",
      max_tokens: 1024,
      messages,
    }),
  );
} catch (e) {
  if (e instanceof InjectionDetectedError) {
    console.log(`Blocked: score=${e.result.score.toFixed(4)}`);
  }
}

Tool use

Claude’s tool-use loop means tool outputs flow back into the messages array as tool_result blocks. Pass those through as role: "tool" messages so Benchspan scans them:

# After the first Claude call with tools
for block in response.content:
    if block.type == "tool_use":
        tool_output = run_tool(block.name, block.input)
        messages.append({
            "role": "user",
            "content": [{
                "type": "tool_result",
                "tool_use_id": block.id,
                "content": tool_output,
            }],
        })

# Next ask_claude() call will scan the tool_output before sending
response = ask_claude(messages)

For scanning tool-result blocks specifically, the simplest pattern is an explicit scan right after the tool runs:

tool_output = run_tool(block.name, block.input)
guard.scan(tool_output, role="tool", source=block.name)  # raises on injection
messages.append({...tool_result block...})

Getting Started

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Anthropic SDK (raw)

Python

TypeScript

Tool use

​Python

​TypeScript

​Tool use

Python

TypeScript

Tool use