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Run: 2026-05-29-01KSSJZB1DC4NCNJX30R215MY1
Run Details
Model:
Claude Opus 4.8 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
41.2s
Cost:
$0.118100
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 heavy rain fell hard against the old mansion windows while Detective Sarah Collins slowly approached the front door. Inside the grand entrance hall, the lifeless body of wealthy patriarch George Whitmore lay sprawled across the cold marble floor. A single heavy silver candlestick rested beside him, its smooth base darkened with the unmistakable crimson stain of dried blood. Detective Collins knelt beside the cooling corpse, studying the deep wound while the heavy storm outside grew louder and angrier. Five frightened guests waited nervously inside the adjoining drawing room, each one harboring dark secrets that someone killed to protect. She rose slowly to her feet, turned toward the trembling crowd, and quietly knew one among them was the murderer.
created_at
"2026-05-29T10:02:44.664Z"
5/29/2026, 10:02:44 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3754
moderation_latency
(null)
generation_time
41164
tokens_prompt
46
tokens_completion
677
native_tokens_prompt
60
native_tokens_completion
4712
native_tokens_completion_images
(null)
native_tokens_reasoning
485
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
0.1181
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_018KytXJFQ2DA4Gk27nV8gqe"
is_byok
false
latency
1147
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-1780048964-ezXB2QNtA2gR0tOHTclv"
session_id
(null)
api_type
"completions"
id
"gen-1780048964-NzIRQUBp5qO5tUCCEogh"
upstream_id
"msg_018KytXJFQ2DA4Gk27nV8gqe"
total_cost
0.1181
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