Run: 2026-05-29-01KSSJRZ0BHWNBQ152AXAXY3W5

Run Details

Model:
Claude Opus 4.8 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 5 words each
Duration:
11.1s
Cost:
$0.022575
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 5 words. Please make sure that each sentence has the same length. Only return the opening itself.

Model response

AI
Rain hammered the old windows. Detective Morgan arrived at midnight. The mansion stood eerily silent. A body lay sprawled inside. Blood pooled across the floor. Nobody had heard the gunshot. Five guests remained completely silent. Lightning flashed through the room. Everyone exchanged nervous, guilty glances. Morgan studied each suspicious face. Someone here was a murderer. The truth waited somewhere inside. Morgan removed her wet coat. The hunt would begin now.
created_at"2026-05-29T09:59:15.733Z" 5/29/2026, 9:59:15 AM
model"anthropic/claude-4.8-opus-20260528"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency4188
moderation_latency(null)
generation_time10991
tokens_prompt46
tokens_completion291
native_tokens_prompt60
native_tokens_completion891
native_tokens_completion_images(null)
native_tokens_reasoning174
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"
usage0.022575
router(null)
provider_responses
0
endpoint_id"b0d3beaa-5ff7-4666-a749-b1bb2b14c916"
id"msg_01V19yfTp5uVSWTw2voSf78C"
is_byokfalse
latency1499
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-1780048755-aHBFIK7LiHuA5Q6EF3Ea"
session_id(null)
api_type"completions"
id"gen-1780048755-Umk3Z35ujuKYCRDSExYe"
upstream_id"msg_01V19yfTp5uVSWTw2voSf78C"
total_cost0.022575
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
sentences14
wordCounts
05
15
25
35
45
55
65
75
85
95
105
115
125
135