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Run: 2026-05-31-01KSYXRQGZJ8QJSQB3ZRX8V6A8
Run Details
Model:
Claude Opus 4.8 (Reasoning, High)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
12.3s
Cost:
$0.029025
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 10 words. Please make sure that each sentence has the same length. Only return the opening itself.
Model response
Messages
Meta
AI
The rain fell hard against the old mansion's tall windows. Detective Sarah Cole arrived just before the clock struck midnight. The butler opened the heavy door without saying a word. Inside, the guests stood frozen around the cold marble staircase. A body lay sprawled upon the floor, blood still warm. The wealthy host, Mister Albert Crane, was clearly quite dead. Sarah knelt down slowly, examining the wound with sharp eyes. Someone here tonight had committed this terrible, calculated, brutal murder. Every face revealed a secret hidden behind a nervous smile. The killer remained among them, watching, waiting, breathing very calmly.
created_at
"2026-05-31T11:47:34.573Z"
5/31/2026, 11:47:34 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3059
moderation_latency
(null)
generation_time
12196
tokens_prompt
46
tokens_completion
282
native_tokens_prompt
60
native_tokens_completion
1149
native_tokens_completion_images
(null)
native_tokens_reasoning
122
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
0.029025
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_01Vrq5A6RUYDveShadYHvGva"
is_byok
false
latency
1027
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-1780228054-y3cBmsORmmaUsljRiJTH"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1780228054-WOLX0BpQYY1jHlRRyiaG"
upstream_id
"msg_01Vrq5A6RUYDveShadYHvGva"
total_cost
0.029025
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
10
wordCounts
0
10
1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10