Enable JSON mode
How to use JSON mode with W&B Inference.
less than a minute
Enabling JSON mode instructs the model to return the response in a valid JSON format. However, the reponse’s schema may not be consistent or adhere to a particular structure. For consistent structured JSON responses, we recommend using structured output when possible.
To enable JSON mode, specify it as the “response_format” in the request:
import json
import openai
client = openai.OpenAI(
base_url='https://api.inference.wandb.ai/v1',
api_key="<your-api-key>", # Available from https://wandb.ai/authorize
)
response = client.chat.completions.create(
model="openai/gpt-oss-20b",
messages=[
{"role": "system", "content": "You are a helpful assistant that outputs JSON."},
{"role": "user", "content": "Give me a list of three fruits with their colors."},
],
response_format={"type": "json_object"} # This enables JSON mode
)
content = response.choices[0].message.content
parsed = json.loads(content)
print(parsed)
curl https://api.inference.wandb.ai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer <your-api-key>" \
-d '{
"model": "openai/gpt-oss-20b",
"messages": [
{"role": "system", "content": "You are a helpful assistant that outputs JSON."},
{"role": "user", "content": "Give me a list of three fruits with their colors."},
],
"response_format": {"type": "json_object"}
}'
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