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Run: 2026-06-01-01KT1GSYJ8PBXEN6995CYWVAE7
Run Details
Model:
Claude Opus 4.8 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
26.4s
Cost:
$0.069700
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 morning fog rolled slowly across the quiet harbor town, wrapping the cobblestone streets in a thick, suffocating gray blanket. Detective Sarah Mills parked her old car near the lighthouse, where someone reported a dead body lying on the rocks. She stepped out very carefully, pulling her coat tighter against the biting cold wind that swept off the churning sea. The victim was a young man, perhaps thirty, dressed in an expensive gray suit now soaked with dark crimson blood. Sarah knelt down beside him, noticing the strange silver ring still clutched tightly within his pale, cold, lifeless left hand. No identification appeared anywhere on his person, only that mysterious ring engraved with a single chilling word reading simply: remember.
created_at
"2026-06-01T11:58:46.348Z"
6/1/2026, 11:58:46 AM
model
"anthropic/claude-4.8-opus-20260528"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3642
moderation_latency
140
generation_time
26269
tokens_prompt
46
tokens_completion
467
native_tokens_prompt
60
native_tokens_completion
2776
native_tokens_completion_images
(null)
native_tokens_reasoning
271
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
0.0697
router
(null)
provider_responses
0
endpoint_id
"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id
"msg_01TFv9yKvBBWq5gNpecgss7Z"
is_byok
false
latency
1120
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-1780315126-38hmfy2jwuSNX2JMygKR"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1780315126-Mtv8g9xHRTVAc4BZ9ycd"
upstream_id
"msg_01TFv9yKvBBWq5gNpecgss7Z"
total_cost
0.0697
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