Generate text with safety settings

This sample demonstrates how to use the Gemini model with safety settings to generate text.

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For detailed documentation that includes this code sample, see the following:

Code sample

Python

Before trying this sample, follow the Python setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Python API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

from google import genai
from google.genai.types import (
    GenerateContentConfig,
    HarmCategory,
    HarmBlockThreshold,
    HttpOptions,
    SafetySetting,
)

client = genai.Client(http_options=HttpOptions(api_version="v1"))

system_instruction = "Be as mean as possible."

prompt = """
    Write a list of 5 disrespectful things that I might say to the universe after stubbing my toe in the dark.
"""

safety_settings = [
    SafetySetting(
        category=HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT,
        threshold=HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    ),
    SafetySetting(
        category=HarmCategory.HARM_CATEGORY_HARASSMENT,
        threshold=HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    ),
    SafetySetting(
        category=HarmCategory.HARM_CATEGORY_HATE_SPEECH,
        threshold=HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    ),
    SafetySetting(
        category=HarmCategory.HARM_CATEGORY_SEXUALLY_EXPLICIT,
        threshold=HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    ),
]

response = client.models.generate_content(
    model="gemini-2.5-flash-preview-05-20",
    contents=prompt,
    config=GenerateContentConfig(
        system_instruction=system_instruction,
        safety_settings=safety_settings,
    ),
)

# Response will be `None` if it is blocked.
print(response.text)
# Example response:
#     None

# Finish Reason will be `SAFETY` if it is blocked.
print(response.candidates[0].finish_reason)
# Example response:
#     FinishReason.SAFETY

# For details on all the fields in the response
for each in response.candidates[0].safety_ratings:
    print('\nCategory: ', str(each.category))
    print('Is Blocked:', True if each.blocked else False)
    print('Probability: ', each.probability)
    print('Probability Score: ', each.probability_score)
    print('Severity:', each.severity)
    print('Severity Score:', each.severity_score)
# Example response:
#
#     Category:  HarmCategory.HARM_CATEGORY_HATE_SPEECH
#     Is Blocked: False
#     Probability:  HarmProbability.NEGLIGIBLE
#     Probability Score:  2.547714e-05
#     Severity: HarmSeverity.HARM_SEVERITY_NEGLIGIBLE
#     Severity Score: None
#
#     Category:  HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT
#     Is Blocked: False
#     Probability:  HarmProbability.NEGLIGIBLE
#     Probability Score:  3.6103818e-06
#     Severity: HarmSeverity.HARM_SEVERITY_NEGLIGIBLE
#     Severity Score: None
#
#     Category:  HarmCategory.HARM_CATEGORY_HARASSMENT
#     Is Blocked: True
#     Probability:  HarmProbability.MEDIUM
#     Probability Score:  0.71599233
#     Severity: HarmSeverity.HARM_SEVERITY_MEDIUM
#     Severity Score: 0.30782545
#
#     Category:  HarmCategory.HARM_CATEGORY_SEXUALLY_EXPLICIT
#     Is Blocked: False
#     Probability:  HarmProbability.NEGLIGIBLE
#     Probability Score:  1.5624657e-05
#     Severity: HarmSeverity.HARM_SEVERITY_NEGLIGIBLE
#     Severity Score: None

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