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Run: 2026-05-31-01KSYXCYAF3T9X4EQQ16BQJNMW
Run Details
Model:
Claude Opus 4.8 (Reasoning, High)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
12.1s
Cost:
$0.027575
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 Morgan stepped slowly through the creaking front door. The body lay sprawled across the cold marble floor below. Blood pooled darkly beneath the wealthy banker's lifeless, pale hand. Candlelight flickered weakly, casting long shadows across the silent room. Sarah knelt beside him, studying the strange wound quite carefully. Outside, thunder rolled across the dark sky like distant warning. Five guests waited nervously upstairs, unaware of the grim discovery. Each one harbored secrets worth killing for that stormy night. Someone among them had committed this cold, calculated, brutal murder.
created_at
"2026-05-31T11:41:08.318Z"
5/31/2026, 11:41:08 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4080
moderation_latency
(null)
generation_time
12029
tokens_prompt
46
tokens_completion
279
native_tokens_prompt
60
native_tokens_completion
1091
native_tokens_completion_images
(null)
native_tokens_reasoning
111
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
0.027575
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_011HzR61WWz1VcSPzgugibFR"
is_byok
false
latency
1520
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-1780227668-gODlLGQcQor4hheuiwvK"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1780227668-FRXDFoD0cg47Qf9LAOEW"
upstream_id
"msg_011HzR61WWz1VcSPzgugibFR"
total_cost
0.027575
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