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Community: Synth 2.5 Flash Preview

synth-2.5-flash

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Synth 2.5 Flash Preview costs $0.039 per million input tokens and $0.130 per million output tokens, supports 30K context, and is available through the OpenAI-compatible API.

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

Modalities

Text → Text

Input / output price

$0.039 / $0.130 per 1M

Context

30K

Capabilities

Roleplay

Pricing

Billed per token actually used and deducted from your credits.

ItemUSD per 1M tokens
Input$0.039
Output$0.130
Cached input$0.0195

Calculator

Drag the sliders to estimate what this model will cost.

Per request
$0.00022
Per day
$0.1105
Per month (30 days)
$3.31

Synth 2.5 Flash Preview: input $0.039/M · output $0.13/M · cached input $0.0195/M

Request with these settings
curl https://api.geniusrelaygpt.com/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "synth-2.5-flash", "max_tokens": 800,
       "messages": [{"role": "user", "content": "…"}]}'

Code samples

OpenAI-compatible. Set the base URL to https://api.geniusrelaygpt.com/v1 and the model to synth-2.5-flash.

curl https://api.geniusrelaygpt.com/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "synth-2.5-flash",
    "stream": true,
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Use it in a client: Cursor · Cline · SillyTavern · Codex

Parameters

Common OpenAI parameters can be passed as-is.

temperaturetop_pmax_tokensstreamstoppresence_penaltyfrequency_penaltyseed

FAQ

How is Synth 2.5 Flash Preview billed?
Input is $0.039 and output is $0.130 per million tokens; cached input is $0.0195. The charge for every request is listed in Usage Logs in the console.
How long is the context window?
30K tokens. In a long conversation every turn is billed for the full input, so keep the history under control.
Does it support streaming?
Yes. Add "stream": true to the request to receive server-sent events in the OpenAI format.
Synth 2.5 Flash Preview API pricing · GeniusRelay