Run: 2026-05-31-01KSYXQE9M5GB5VQ2VP6XZ93JS

Run Details

Model:
Claude Opus 4.8 (Reasoning, High)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
13.3s
Cost:
$0.032850
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

AI
The rain hammered hard against the windows of Blackwood Manor. Detective Sarah Cole arrived just before the storm grew worse. Inside, the wealthy host lay dead upon the marble floor. His five guests gathered nervously around the cold, lifeless body. Nobody admitted hearing the gunshot that ended his troubled life. Sarah studied each suspicious face, searching quietly for hidden guilt. Someone standing in this elegant room was clearly a murderer. The truth, she knew, would surface before the dawn arrived.
created_at"2026-05-31T11:46:52.354Z" 5/31/2026, 11:46:52 AM
model"anthropic/claude-4.8-opus-20260528"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency3545
moderation_latency(null)
generation_time13203
tokens_prompt46
tokens_completion215
native_tokens_prompt60
native_tokens_completion1302
native_tokens_completion_images(null)
native_tokens_reasoning87
native_tokens_cached0
num_media_prompt(null)
num_input_audio_prompt(null)
num_media_completion0
num_search_results(null)
num_fetches(null)
web_search_engine(null)
origin"https://ncbench.com/"
is_byokfalse
finish_reason"stop"
native_finish_reason"end_turn"
service_tier"default"
usage0.03285
router(null)
provider_responses
0
endpoint_id"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id"msg_01YTaJNUgSMYXHTsC4BMshJZ"
is_byokfalse
latency1022
model_permaslug"anthropic/claude-4.8-opus-20260528"
provider_name"Anthropic"
status200
user_agent"langchainjs-openai/1.0.0 ((node/v24.16.0; linux; x64))"
http_referer(null)
request_id"req-1780228012-IBrz5QtoQgZcRyn5bFBx"
session_id(null)
preset_id(null)
api_type"completions"
id"gen-1780228012-wgHF8p54Wz7811skpc7g"
upstream_id"msg_01YTaJNUgSMYXHTsC4BMshJZ"
total_cost0.03285
cache_discount(null)
upstream_inference_cost0
provider_name"Anthropic"
response_cache_source_id(null)

Evaluation details

Result Evaluator Details Meta Data
100.00% Matches word count n/a
neededCleanfalse
sentences8
wordCounts
010
110
210
310
410
510
610
710