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Run: 2026-09-23-01M37P1CHJRZH6A8MX5A5DKB2G
Run Details
Model:
Claude Opus 5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
15.8s
Cost:
$0.030128
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 10 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 all night long. Inside, the grandfather clock struck midnight with a hollow groan. Eleanor Hart descended the staircase, clutching a flickering silver candle. She had heard a scream, sharp and sudden, then silence. The study door stood ajar, spilling pale light into darkness. Her uncle Reginald lay slumped across his mahogany writing desk. A thin ribbon of blood trickled down his pale temple. His fountain pen still rested between his cold, stiff fingers. Eleanor noticed the window was firmly locked from the inside. Yet the fireplace poker lay gleaming wetly upon the rug. Behind her, footsteps creaked softly across the old oak floorboards. She turned slowly, and the candle flame suddenly went out. "Nobody leaves this house tonight," whispered a voice she recognized.
created_at
"2026-09-23T17:46:55.939Z"
9/23/2026, 5:46:55 PM
model
"anthropic/claude-opus-5.5-20260921"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4631
moderation_latency
(null)
generation_time
15791
tokens_prompt
46
tokens_completion
415
native_tokens_prompt
62
native_tokens_completion
1494
native_tokens_completion_images
(null)
native_tokens_reasoning
1198
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
0.030128
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.20.0; linux; x64))"
http_referer
(null)
request_id
"req-1790185615-PksskbATJNXQGgSUG2pI"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1790185615-WtB8sDh9EzblmJjovLWr"
upstream_id
"msg_011CfLnmiC9ZjX9mk4VigGuo"
provider_responses
0
endpoint_id
"3a2388bc-3740-4e64-a1f5-4e301726b6b9"
id
"msg_011CfLnmiC9ZjX9mk4VigGuo"
is_byok
false
latency
1343
model_permaslug
"anthropic/claude-opus-5.5-20260921"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.030128
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
13
wordCounts
0
10
1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
10
10
11
10
12
10