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Run: 2026-09-29-01M3P2APXAKQ1H07WDVB7Q5D3E
Run Details
Model:
Claude Sonnet 5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
17.2s
Cost:
$0.022774
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
Rain hammered the windows of Blackwood Manor the night Lord Alistair Finch was found dead in his own locked study. Inspector Mara Quinn arrived after midnight, her boots soaked, her patience thinner than the fog curling across the gravel drive. The butler, a stooped man named Hobbs, met her at the door and whispered that nobody had touched anything, ma'am. Inside the study, Finch slumped over his mahogany desk, one hand outstretched toward a porcelain teacup that had not spilled. The heavy oak door had been bolted from the inside, and the only tall window was painted shut decades ago. Quinn knelt beside the body and noticed a faint, bitter smell of almonds still clinging to the dead man's collar. Behind her, the family gathered in the doorway: a pale widow, a nephew, a physician, and a silent young secretary. Every one of them claimed to have heard nothing, yet somebody had wound the old clock on the mantel backward. Quinn straightened slowly, studied each face in turn, and felt certain that the killer was still standing within arm's reach.
created_at
"2026-09-29T07:51:06.419Z"
9/29/2026, 7:51:06 AM
model
"anthropic/claude-sonnet-5.5-20260928"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3897
moderation_latency
(null)
generation_time
17150
tokens_prompt
46
tokens_completion
538
native_tokens_prompt
62
native_tokens_completion
2265
native_tokens_completion_images
(null)
native_tokens_reasoning
1902
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
0.022774
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1790668266-eX3tbpBaihVjhjm2tnPg"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1790668266-T8CmRoXSEq8CQpgQakwz"
upstream_id
"msg_011CfXNBx2tqaUBQajrqK2Lo"
provider_responses
0
endpoint_id
"99aaad94-923b-4fc1-b763-271ed5486f7a"
id
"msg_011CfXNBx2tqaUBQajrqK2Lo"
is_byok
false
latency
695
model_permaslug
"anthropic/claude-sonnet-5.5-20260928"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.022774
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