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Run: 2026-05-29-01KSSJEFWZKSD1KDGNRDBC3WP5
Run Details
Model:
Claude Opus 4.8 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
19.2s
Cost:
$0.048825
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 rain hammered against the old mansion windows as Detective Sarah Cole stepped carefully across the cold marble entrance hall. A single lifeless body lay sprawled beneath the grand staircase, surrounded by shattered glass and a spreading pool of blood. The victim, the wealthy banker Edmund Harlow, had clearly fallen from the upper landing during last night's lavish dinner party. Sarah crouched low, studying the angle of his broken neck and the strange bruises marking both of his pale wrists. Someone in this house had pushed him deliberately, and that someone was still hiding among the frightened, whispering overnight guests. Six guests waited nervously in the drawing room, each clutching secrets they desperately hoped the detective would never quite uncover. Sarah rose slowly, brushed off her coat, and turned toward them with a calm, knowing smile that promised relentless justice.
created_at
"2026-05-29T09:53:32.801Z"
5/29/2026, 9:53:32 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3361
moderation_latency
(null)
generation_time
18674
tokens_prompt
46
tokens_completion
385
native_tokens_prompt
60
native_tokens_completion
1941
native_tokens_completion_images
(null)
native_tokens_reasoning
161
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
0.048825
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
is_byok
false
latency
231
model_permaslug
"anthropic/claude-4.8-opus-20260528"
provider_name
"Anthropic"
status
429
1
endpoint_id
"dfc0e5bd-d703-4fe2-a7bb-655eb95d5441"
id
"msg_01Dck7QqgYJKr6aaUWY5hn29"
is_byok
false
latency
979
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-1780048412-Mf3QsheYBitdzWTOgt53"
session_id
(null)
api_type
"completions"
id
"gen-1780048412-IsZ0dWLYCCaO9XGNCtll"
upstream_id
"msg_01Dck7QqgYJKr6aaUWY5hn29"
total_cost
0.048825
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