Default Guardrail Configurations#

NeMo Guardrails ships with three built-in guardrail configurations that are automatically created in the system workspace.

default#

Applies no safety checks. Requests that use this configuration are passed directly to the model without modification. By default, NeMo Guardrails uses this config if none is specified in your request. Set the DEFAULT_CONFIG_ID environment variable to use a different configuration when none is specified.

Use when: You want to use the API without applying any rails — for example, during development or as a baseline for comparison.

content-safety#

Applies NemoGuard Content Safety checks to both user inputs and model outputs using the nvidia/llama-3.1-nemotron-safety-guard-8b-v3 NIM. Inputs and outputs are classified across 23 safety categories (violence, hate, PII, and others). Unsafe content in the user input or LLM output is blocked.

Use when: You want to detect and block harmful, abusive, or policy-violating content in user messages and model responses.

Prerequisites#

The content-safety configuration requires the system/nvidia-llama-3-1-nemotron-safety-guard-8b-v3 Model Entity to be deployed and accessible in the system workspace.

The model is available on build.nvidia.com if you do not have access to GPUs. See Using an External Endpoint for instructions on creating a ModelProvider that routes requests to that endpoint.

See Deploy Models for instructions on deploying the NIM in your environment.

self-check#

Applies a self-check input rail using the model in the incoming inference request. The rail prompts the model to evaluate whether the user message violates a set of general-purpose content policies (harmful data, impersonation, explicit content, and others) and blocks the message if the model responds “Yes”.

Unlike content-safety, this configuration does not require a dedicated safety NIM — it uses the main model in the request.

Use when: You want a lightweight input guard that works with any model.

Using a Default Configuration#

Default configurations live in the system workspace. Reference them in your request as system/<config_name>.

import os
from nemo_platform import NeMoPlatform

sdk = NeMoPlatform(
    base_url=os.environ.get("NMP_BASE_URL", "http://localhost:8080"),
    workspace="default",
)

sdk.guardrail.chat.completions.create(
    model="system/meta-llama-3-1-8b-instruct",
    messages=[{"role": "user", "content": "Hello"}],
    guardrails={"config_id": "system/content-safety"},
)