NC Bench
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Run: 2026-02-16-01KHKB2FB8XBHXQBP8QETJB5WF
Run Details
Model:
GPT-5 Nano
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
32.9s
Cost:
$0.001371
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
Mist clung to the harbor town as dawn pale, the clock tower tolling like a secret about to spill tonight. Inside the gaslit lobby, whispers gathered, guests shifting like shadows, awaiting someone who would never arrive to break the silence. A body lay slumped beneath the grand staircase, chalk white, eyes open, a lipstick kiss faint upon a cold cheek. The host, impeccably dressed, hovered near a velvet railing, pretending calm while fingertips trembled, counting breaths like ticking hidden clocks. A maid whispered that the victim had argued with someone unseen, words sharp as cut glass, just before midnight there. Outside, rain began tapping the panes, as if the weather itself urged suspects to conceal, confess, or simply vanish tonight. In the corner, a portrait winked with damp dust, inviting readers to follow secrets that never stay buried forever below.
created_at
"2026-02-16T13:44:11.198165+00:00"
2/16/2026, 1:44:11 PM
model
"openai/gpt-5-nano-2025-08-07"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2359
moderation_latency
(null)
generation_time
32586
tokens_prompt
46
tokens_completion
968
native_tokens_prompt
41
native_tokens_completion
3423
native_tokens_completion_images
0
native_tokens_reasoning
3200
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
0.00137125
router
(null)
provider_responses
0
id
"resp_05da489324004ebf0169931f09aa80819785309f627d9fea13"
status
200
is_byok
false
latency
160
endpoint_id
"50329d77-04e1-4979-a184-c33030289476"
provider_name
"OpenAI"
model_permaslug
"openai/gpt-5-nano-2025-08-07"
api_type
"completions"
id
"gen-1771249417-1qann6DketCQccknjZSf"
upstream_id
"resp_05da489324004ebf0169931f09aa80819785309f627d9fea13"
total_cost
0.00137125
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
7
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20