NC Bench
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Run: 2026-02-16-01KHKAGEPPH1GQ1DC8W61CFV2E
Run Details
Model:
GPT-5 Nano
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
35.8s
Cost:
$0.001344
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
The town awoke beneath pale dawn, and the old observatory loomed like a watchful sentinel above rumors tonight and fears. Detective Mara Lenz arrived with rain on her coat, following whispers that something crooked had fractured the morning before breakfast. Inside, the circular chamber hummed with quiet electricity, as if the telescope sighed after centuries of silence and starlight breath. On the console lay a chalkboard with numbers, and beneath it, a body draped in a velvet cloak and silence. The clock ticked irregularly, each echo a question, as if time itself hesitated before unveiling the killer's motive to justice. From the hallway, a librarian whispered about forged alibis and a vanished map rumored to reveal the thief that night. Outside, the wind hissed through broken panes, carrying a scent of sulfur and old coins from forgotten safes in basements. A note scrawled in chalk read that the truth hides where light cannot shine, and the room listened in silence. Mara stepped closer, tracing dust on the telescope mount, noting footprints leading toward the fogged glass and nothing else there.
created_at
"2026-02-16T13:34:23.60708+00:00"
2/16/2026, 1:34:23 PM
model
"openai/gpt-5-nano-2025-08-07"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3298
moderation_latency
(null)
generation_time
34928
tokens_prompt
46
tokens_completion
1100
native_tokens_prompt
41
native_tokens_completion
3355
native_tokens_completion_images
0
native_tokens_reasoning
3072
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
0.00134405
router
(null)
provider_responses
0
id
"resp_01d0be231d05ecdb0169931cbb3630819784a193ec1a3b78d4"
status
200
is_byok
false
latency
126
endpoint_id
"50329d77-04e1-4979-a184-c33030289476"
provider_name
"OpenAI"
model_permaslug
"openai/gpt-5-nano-2025-08-07"
api_type
"completions"
id
"gen-1771248827-oQcMDA0bkb6MZMgbJ6qA"
upstream_id
"resp_01d0be231d05ecdb0169931cbb3630819784a193ec1a3b78d4"
total_cost
0.00134405
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
9
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20
7
20
8
20