Run: 2026-05-31-01KSYXJA152HC95XGZPZTV8HA3

Run Details

Duration:
28.8s
Cost:
$0.073475
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

AI
The cold rain hammered against the old mansion windows as Detective Sarah Cole stepped carefully across the muddy gravel driveway. Inside the grand foyer, a single body lay sprawled beneath the crystal chandelier, blood pooling slowly across cold marble tiles. Five frightened guests gathered nervously inside the candlelit parlor, each one wearing a mask of shock concealing their terrible secrets. Sarah knelt beside the victim, recognizing the famous millionaire whose vast fortune had attracted enemies from every corner of society. A single jeweled letter opener protruded from his chest, glinting beneath the lights like an accusation no one could ignore. Outside, thunder rolled across the darkened evening sky while Sarah slowly realized the killer was still somewhere inside this house.
created_at"2026-05-31T11:44:04.146Z" 5/31/2026, 11:44:04 AM
model"anthropic/claude-4.8-opus-20260528"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency4890
moderation_latency(null)
generation_time28713
tokens_prompt46
tokens_completion564
native_tokens_prompt60
native_tokens_completion2927
native_tokens_completion_images(null)
native_tokens_reasoning365
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"
usage0.073475
router(null)
provider_responses
0
endpoint_id"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id"msg_01UB7MfUCHTaSf8SShyaLBUR"
is_byokfalse
latency2377
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-1780227844-WfPzXGLPVafrq63YXO8Q"
session_id(null)
preset_id(null)
api_type"completions"
id"gen-1780227844-JdjNQsNXN6fRJ5jb4Q6n"
upstream_id"msg_01UB7MfUCHTaSf8SShyaLBUR"
total_cost0.073475
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
sentences6
wordCounts
020
120
220
320
420
520