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Run: 2026-09-23-01M37PQ1NREFXMPAJP3X9JY5J7
Run Details
Model:
Claude Opus 5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
18.8s
Cost:
$0.037128
Provider:
Claude Platform on AWS
Evaluation summary
Score
Evaluator
Details Link
100.00%
Matches word count
(details)
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 rain had not stopped for three days when Inspector Clara Voss arrived at the iron gates of Harrowgate Manor. A young constable waited beneath a black umbrella, his face pale, his hands trembling as he opened her car door. "The body is in the library, ma'am," he whispered, as though the dead man might somehow still overhear them talking. Clara stepped inside, shaking water from her coat, and noticed immediately that every clock in the hallway had been stopped. Each one showed the same time, a quarter past midnight, their brass hands frozen like silent witnesses refusing to speak. In the library, Lord Edmund Harrow sat slumped in his leather armchair, a glass of brandy still in his hand. His eyes were open, fixed upon the portrait of his late wife that hung above the cold grey stone fireplace. Four members of the household had gathered by the window, and Clara sensed that at least one was already lying. "Nobody touched him," the butler said stiffly, but Clara saw the faint red smear of lipstick on the brandy glass.
created_at
"2026-09-23T17:58:45.706Z"
9/23/2026, 5:58:45 PM
model
"anthropic/claude-opus-5.5-20260921"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4918
moderation_latency
(null)
generation_time
18738
tokens_prompt
46
tokens_completion
564
native_tokens_prompt
62
native_tokens_completion
1844
native_tokens_completion_images
(null)
native_tokens_reasoning
1498
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
num_fetches
(null)
web_search_engine
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"end_turn"
service_tier
"default"
usage
0.037128
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.20.0; linux; x64))"
http_referer
(null)
request_id
"req-1790186325-ptsUxqlyUgAyACQmkzlF"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1790186325-uVFYwx4lnNUawfyDVNtb"
upstream_id
"msg_011CfLog3KY23GMyEiLZXdz9"
provider_responses
0
endpoint_id
"3a2388bc-3740-4e64-a1f5-4e301726b6b9"
id
"msg_011CfLog3KY23GMyEiLZXdz9"
is_byok
false
latency
1566
model_permaslug
"anthropic/claude-opus-5.5-20260921"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.037128
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Claude Platform on AWS"
response_cache_source_id
(null)
data_region
"global"
workspace_id
"97e315e5-d303-487d-83c1-83180e8a13d4"
Evaluation details
Result
Evaluator
Details
Meta Data
100.00%
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