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Run: 2026-06-01-01KT1J6EBBZT9X6S9MK92EC2D9
Run Details
Model:
Claude Opus 4.8 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
28.8s
Cost:
$0.080575
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 cold rain hammered against the old mansion windows, drumming a relentless rhythm that nobody inside seemed willing to acknowledge. Inside the grand dining hall, seven nervous guests sat frozen around the table, staring at the body slumped across it. Lord Ashford had been alive just moments ago, laughing loudly while raising his crystal wine glass toward the flickering chandelier. Now his pale face lay pressed against the white tablecloth, a thin trickle of blood staining the embroidered linen crimson. Detective Mara Vance stepped forward slowly, removing her wet leather gloves while scanning each shocked face for hidden guilty secrets. Somebody sitting in this beautiful, candlelit room had committed murder, and she intended to discover exactly who before midnight arrived.
created_at
"2026-06-01T12:23:04.304Z"
6/1/2026, 12:23:04 PM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3750
moderation_latency
(null)
generation_time
28818
tokens_prompt
46
tokens_completion
417
native_tokens_prompt
60
native_tokens_completion
3211
native_tokens_completion_images
(null)
native_tokens_reasoning
220
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
0.080575
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_016UAH9cBERP6v861pFJa4KQ"
is_byok
false
latency
1154
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-1780316584-HQoRNz3bYq58x5FjpPip"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1780316584-uiqCGERNeYoiFZhcVUgF"
upstream_id
"msg_016UAH9cBERP6v861pFJa4KQ"
total_cost
0.080575
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