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Run: 2026-05-31-01KSYXJM31B2108RZ309Q18GS6
Run Details
Model:
Claude Opus 4.8 (Reasoning, High)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
45.4s
Cost:
$0.117450
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 manor windows as Detective Sarah Cole stepped slowly across the creaking wooden floor. A single lifeless body lay sprawled beneath the grand staircase, blood pooling darkly across the priceless antique Persian carpet below. The wealthy old victim, Lord Edmund Harrington, had hosted twelve dinner guests tonight, and each one was a prime suspect. Sarah crouched down low beside the corpse and noticed something glinting faintly within the dead man's tightly clenched right hand. She carefully pried the cold stiff fingers apart and discovered a small silver locket engraved with two unfamiliar golden initials. Outside, thunder cracked violently overhead as the manor's heavy front door suddenly burst open, revealing a soaked, trembling young figure. Sarah rose slowly to her feet, her hand instinctively reaching toward her holster, knowing this terrible night had just begun.
created_at
"2026-05-31T11:44:14.444Z"
5/31/2026, 11:44:14 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3933
moderation_latency
(null)
generation_time
45334
tokens_prompt
46
tokens_completion
648
native_tokens_prompt
60
native_tokens_completion
4686
native_tokens_completion_images
(null)
native_tokens_reasoning
408
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
0.11745
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_019diXyXkjLPdYooGoTCxLTk"
is_byok
false
latency
1238
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-1780227854-DF2byAhpqFHAKC23ZrKx"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1780227854-Mrm408hleYW1UsjWT8jF"
upstream_id
"msg_019diXyXkjLPdYooGoTCxLTk"
total_cost
0.11745
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
7
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20