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lucidity · Efficient

Synth 2.5 Flash Preview

Added Sep 5, 2026

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Use in the app

Synth 2.5 Flash Preview is a low-cost text model designed for role-play, character dialogue, and collaborative storytelling.

Input
Text
Output
Text
Discovery tier
Efficient

Pricing

USD per 1M tokens
Input
$0.03
Output
$0.10

Reference prices as published by the model provider. API example

Specifications

Context window
30K
Max output
—

Side by side

Synth 2.5 Flash Preview compared

Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.

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Synth 2.5 Flash PreviewlucidityThis modelSynth 2.5 Pro PreviewlucidityRemove
Providerluciditylucidity
Discovery tierEfficientEfficient
AddedSep 5, 2026Sep 5, 2026
Limits
Context window30K30K
Pricing, USD per 1M tokens
Input$0.03Best$0.10
Output$0.10Best$0.20
Performance
Request success (24h)—0.0%
Capabilities
Reasoning effort——

Public evaluations

Benchmarks

There are no public benchmark results for these models yet.

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "synth-2.5-flash",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'
import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="synth-2.5-flash",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

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