noma-langchain-integration 0.1.1

Noma guardrail middleware integration for LangChain

noma-langchain-integration

Noma guardrail middleware for LangChain agents. Scans user and assistant messages to detect and handle unsafe content before and after agent execution.

Installation

pip install noma-langchain-integration

Quick start

from langchain.agents import create_agent
from langchain_noma.middleware import NomaGuardrailMiddleware

middleware = NomaGuardrailMiddleware(
    api_key="noma-...",  # or set NOMA_API_KEY env var
)

agent = create_agent(
    model="openai:gpt-4.1",
    tools=[...],
    middleware=[middleware],
)

The middleware runs two hooks automatically:

• before_agent — scans user messages before the agent processes them.
• after_agent — scans assistant messages after the agent responds.

Both sync and async hooks are supported (abefore_agent, aafter_agent).

Configuration

All parameters are optional and keyword-only:

Parameter	Type	Default	Description
api_key	str | None	NOMA_API_KEY env	API key for the Noma service. Required when using the Noma SaaS endpoint.
application_id	str | None	NOMA_APPLICATION_ID env or "langchain"	Application identifier sent with each scan request.
block_failures	bool	True	When True (fail-closed), block requests if the AIDR API is unreachable. When False (fail-open), allow requests through on scan failure.

Environment variables

Variable	Required	Description
NOMA_API_KEY	Yes (SaaS)	API key. Can also be passed via the api_key constructor parameter.
NOMA_APPLICATION_ID	No	Override the application identifier (defaults to "langchain").