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Run: 2026-05-29-01KSSK6V4YV5JN661HZJHHVMR0
Run Details
Model:
Claude Opus 4.8 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
21.2s
Cost:
$0.050500
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 hammered against the windows of old Blackwood manor. Detective Hartley arrived just before midnight, cold, soaked, and tired. The heavy front door stood wide open in the storm. Inside, a lifeless body lay sprawled across the cold floor. Lord Blackwood's lifeless eyes stared blankly toward the high ceiling. Blood pooled darkly beneath him, staining the expensive antique rug. Hartley knelt down slowly, examining the man's cold, pale face. Somewhere upstairs, a single floorboard creaked beneath a careful step. He froze, listening intently, hand reaching slowly toward his holster. The killer, he realized, had not yet left the house.
created_at
"2026-05-29T10:06:50.538Z"
5/29/2026, 10:06:50 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3973
moderation_latency
(null)
generation_time
21205
tokens_prompt
46
tokens_completion
360
native_tokens_prompt
60
native_tokens_completion
2008
native_tokens_completion_images
(null)
native_tokens_reasoning
183
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
0.0505
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_01LjLmcybAXXCRR6S4Ka2cB4"
is_byok
false
latency
1275
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-1780049210-G4CXnk6dha3sVJ0YBP7d"
session_id
(null)
api_type
"completions"
id
"gen-1780049210-FC0XLx4e355ecGezHV2i"
upstream_id
"msg_01LjLmcybAXXCRR6S4Ka2cB4"
total_cost
0.0505
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