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Run: 2026-09-23-01M37Q9ZAVH9H0KDVEHFK709PH
Run Details
Model:
Claude Opus 5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
18.7s
Cost:
$0.038808
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
The storm arrived at Blackwood Manor just after midnight struck. Lightning split the sky above the old stone chapel roof. Inside, eight guests sat waiting in the dimly lit library. Their host, Lord Edmund Ashford, had not appeared for dinner. The butler, Graves, stood silently beside the crackling marble fireplace. Margaret Ashford checked her pearl watch for the third time. "Something is wrong," she whispered to no one in particular. Then a single scream echoed down from the east wing. Everyone froze, glasses halfway to their lips, eyes wide open. Graves was the first to reach the heavy oak staircase. The others followed, their footsteps thundering against the polished floorboards. At the study door, a young maid stood trembling violently. Her white apron was stained with something dark and wet. Beyond her, Lord Ashford lay slumped across his mahogany desk. A silver letter opener protruded from between his shoulder blades. The window was locked, and the only key was missing. Margaret turned slowly, studying each pale face in the corridor. One of them had killed him, and she knew it.
created_at
"2026-09-23T18:09:05.904Z"
9/23/2026, 6:09:05 PM
model
"anthropic/claude-opus-5.5-20260921"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4933
moderation_latency
(null)
generation_time
18597
tokens_prompt
46
tokens_completion
467
native_tokens_prompt
62
native_tokens_completion
1928
native_tokens_completion_images
(null)
native_tokens_reasoning
1556
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
0.038808
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.20.0; linux; x64))"
http_referer
(null)
request_id
"req-1790186945-dzlF4Ghm5lpSSos9Hxxs"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1790186945-EwCSbxb5zSxSApCBi62v"
upstream_id
"msg_011CfLpTkFAF8cERcD3nLwWe"
provider_responses
0
endpoint_id
"3a2388bc-3740-4e64-a1f5-4e301726b6b9"
id
"msg_011CfLpTkFAF8cERcD3nLwWe"
is_byok
false
latency
1160
model_permaslug
"anthropic/claude-opus-5.5-20260921"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.038808
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
18
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
13
10
14
10
15
10
16
10
17
10