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Run: 2026-10-08-01M4DAJMC8YN6PQ8YXCEWRMG76
Run Details
Model:
Claude Haiku 5.5 (Reasoning, Medium)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
9.2s
Cost:
$0.001019
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 fallen across Blackwood Manor since midnight, washing the gravel paths clean of every single footprint before dawn. Detective Inspector Harriet Vane arrived at the estate just after seven, her coat soaked and her temper already frayed badly. Lord Edmund Ashcombe lay face down in his library, a silver letter opener protruding from between his narrow shoulder blades. The constable at the scene, a nervous young man named Pike, insisted that nobody had entered or left since nine. Harriet knelt beside the body, noticing a faint smear of ink on the victim's right cuff that nobody had mentioned. Somewhere in the house, a clock chimed eleven times, and every guest in the drawing room fell silent at once. Harriet looked up slowly, and she knew with absolute certainty that one of them was lying to her face tonight.
created_at
"2026-10-08T08:37:46.512Z"
10/8/2026, 8:37:46 AM
model
"anthropic/claude-haiku-5.5-20261007"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2893
moderation_latency
(null)
generation_time
9154
tokens_prompt
46
tokens_completion
383
native_tokens_prompt
62
native_tokens_completion
2026
native_tokens_completion_images
(null)
native_tokens_reasoning
1745
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
0.0010192
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1791448666-lKMfngMIRmlpk4NbnHaQ"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1791448666-Q8oIm0HCikmPadtO0lvL"
upstream_id
"msg_011CfpU2cH1Y42ZGByaohfd2"
provider_responses
0
endpoint_id
"b6cdf493-3a61-441f-a134-e7944fddb980"
id
"msg_011CfpU2cH1Y42ZGByaohfd2"
is_byok
false
latency
763
model_permaslug
"anthropic/claude-haiku-5.5-20261007"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.0010192
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
7
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20