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Run: 2026-06-01-01KT1GVTVTJG5WTTBSZPJ267A3
Run Details
Model:
Claude Opus 4.8 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
42.2s
Cost:
$0.120900
Provider:
Anthropic
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 fell steadily against the tall windows of Blackwood Manor as Detective Sarah Chen approached the heavy oak door. Inside the dimly lit study, the lifeless body of wealthy businessman Edward Hartwell lay sprawled across his elegant Persian rug. A single bullet wound had marred his broad chest, and his cold eyes stared blankly toward the crackling fireplace nearby. Sarah pulled on her leather gloves slowly, carefully scanning the entire room while three nervous guests watched from the hallway. The grieving widow, the business partner, and the estranged son each claimed they had never left the crowded dinner party. But someone hidden inside this isolated manor was clearly lying, and Sarah intended to uncover the deadly truth before midnight.
created_at
"2026-06-01T11:59:48.102Z"
6/1/2026, 11:59:48 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3355
moderation_latency
(null)
generation_time
42219
tokens_prompt
46
tokens_completion
546
native_tokens_prompt
60
native_tokens_completion
4824
native_tokens_completion_images
(null)
native_tokens_reasoning
348
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
0.1209
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_01DXENBJnoGas8T5BkAc3qtq"
is_byok
false
latency
1211
model_permaslug
"anthropic/claude-4.8-opus-20260528"
provider_name
"Anthropic"
status
200
user_agent
"langchainjs-openai/1.0.0 ((node/v24.16.0; linux; x64))"
http_referer
(null)
request_id
"req-1780315188-dsVHqGALE0ntRA09EVoe"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1780315188-4cY90WYh8rVHLrb9rBxy"
upstream_id
"msg_01DXENBJnoGas8T5BkAc3qtq"
total_cost
0.1209
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
response_cache_source_id
(null)
Evaluation details
Result
Evaluator
Details
Meta Data
100.00%
Matches word count
n/a
neededClean
false
sentences
6
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20