NC Bench
Overview
About
Tests
Categories
Models
Vendors
Compare
Run: 2026-10-08-01M4D9W8MGE90ZXZQ408GB43FV
Run Details
Model:
Claude Haiku 5.5 (Reasoning, Medium)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
19.6s
Cost:
$0.002156
Provider:
Claude Platform on AWS
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 rain had fallen all night on Harrow Lane, washing the old streetlamps into smeared pools of trembling amber light. Detective Inspector Mara Quill stood beside the wet iron gate, her breath clouding in the bitter November air above it. Behind her, uniformed officers stretched yellow tape across the hedges, muttering quietly among themselves about the unusually early hour today. Inside the shadowed conservatory, the body of Lord Edmund Ashcombe lay slumped across a wicker chair beside an overturned teacup. Nobody had touched the teacup, which still held a dark residue that smelled faintly of bitter almonds and something sweeter. Mara crouched beside the body, noting the stiff fingers, the torn lace cuff, and the muddy footprint near the door. Her partner, Sergeant Tom Hale, lingered in the doorway, scribbling notes with a stubby pencil he kept nervously chewing on. Mara stood, brushed grit from her knees, and studied the room with quiet patience that had earned her a reputation. Nothing in the room had been disturbed, so the killer had either been invited in or known this house intimately. Mara turned toward the window, where a strange faint reflection caught her eye, and whispered quietly this was no accident.
created_at
"2026-10-08T08:25:33.804Z"
10/8/2026, 8:25:33 AM
model
"anthropic/claude-haiku-5.5-20261007"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2362
moderation_latency
(null)
generation_time
19349
tokens_prompt
46
tokens_completion
826
native_tokens_prompt
62
native_tokens_completion
4299
native_tokens_completion_images
(null)
native_tokens_reasoning
3878
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
0.0021557
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1791447933-YqgCwpwaljnazeKJGyxm"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1791447933-vyWSJk0ZXIyqhF9l7S07"
upstream_id
"msg_011CfpT6bCX7aizLT4SFdRG7"
provider_responses
0
endpoint_id
"b6cdf493-3a61-441f-a134-e7944fddb980"
id
"msg_011CfpT6bCX7aizLT4SFdRG7"
is_byok
false
latency
808
model_permaslug
"anthropic/claude-haiku-5.5-20261007"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.0021557
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Claude Platform on AWS"
response_cache_source_id
(null)
data_region
"global"
workspace_id
"97e315e5-d303-487d-83c1-83180e8a13d4"
Evaluation details
Result
Evaluator
Details
Meta Data
100.00%
Matches word count
n/a
neededClean
false
sentences
10
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20
7
20
8
20
9
20