NC Bench
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Run: 2026-02-16-01KHK9WS09Z1VRPRJ98WX3NJFJ
Run Details
Model:
GPT-5 Nano
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
47.4s
Cost:
$0.001460
Provider:
OpenAI
Model input
User/Human
Please write the opening scene of a murder mystery where each sentence has exactly 20 words. Please make sure that each sentence has the same length. Only return the opening itself.
Model response
Messages
Meta
AI
Rain smeared the city windows as dawn approached, and Detective Mara Voss surveyed the quiet rain washed street below silently. A body lay beneath a flickering streetlamp, velvet cloak pooled crimson, and witnesses whispered murder beside trembling pigeons inconsolably tonight. The victim wore an antiquated brooch shaped like a moth, pinprick revealing something darker beneath glittering surface masking secrets hidden. A velvet rope remained around the crime scene, but someone had slipped a note beneath it, ink still damp tonight. The note, folded twice, bore only initials and a date scrawled in hurried, anxious script that did not belong here. Dawn brightened, but the city felt heavier, as if every passerby concealed a motive, every alley listening to whispers everywhere.
created_at
"2026-02-16T13:23:50.099078+00:00"
2/16/2026, 1:23:50 PM
model
"openai/gpt-5-nano-2025-08-07"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3254
moderation_latency
(null)
generation_time
46727
tokens_prompt
46
tokens_completion
873
native_tokens_prompt
41
native_tokens_completion
3645
native_tokens_completion_images
0
native_tokens_reasoning
3456
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"completed"
usage
0.00146005
router
(null)
provider_responses
0
id
"resp_0d5fc9996791121b0169931a366288819695c8bec287fd0820"
status
200
is_byok
false
latency
137
endpoint_id
"50329d77-04e1-4979-a184-c33030289476"
provider_name
"OpenAI"
model_permaslug
"openai/gpt-5-nano-2025-08-07"
api_type
"completions"
id
"gen-1771248182-yvtcOUc1RJrkZDO57Hzr"
upstream_id
"resp_0d5fc9996791121b0169931a366288819695c8bec287fd0820"
total_cost
0.00146005
cache_discount
(null)
upstream_inference_cost
0
provider_name
"OpenAI"
Evaluation details
Result
Evaluator
Details
Meta Data
100.0000%
Matches word count
n/a
neededClean
false
sentences
6
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20