---
title: "What is Clef Flash: the low-cost text-and-image decision model for high-volume, cost-sensitive work | system-one.dev"
description: "Clef Flash is the cheapest of the three Clef models. It reads text and images and returns a choice, a score, or a yes/no probability. Use it for high-volume, cost-sensitive classification and routing. Sign in to try live."
canonical: "https://system-one.dev/en/models/clef-flash"
language: "en"
---

# Clef Flash

The cheapest of the three Clef models. Use it for high-volume, cost-sensitive classification and routing.

**What is Clef Flash?** Clef Flash is a decision model provided by system-one.dev for high-volume, cost-sensitive classification and routing. It reads text, JSON, and images. Ask a few questions (pick one, score, or yes/no) and it returns a choice, a score, or a yes/no probability without generating text. Among the three Clef models it is the cheapest, so start image tasks here; if the result is not good enough, compare [Clef](https://system-one.dev/en/models/clef). Call it with the TypeScript SDK or the API. Billing is in credits; the rate is in Model info on this page.

Sign in to try live: [Try live (sign in required)](https://system-one.dev/en/demo)


## Model info

- Provided by: system-one.dev
- 3 credits per question per 4KB
- Up to 32 questions · 13MB per request
- Inputs: text, JSON, and images (PNG, JPEG, WebP)
- Images: up to 4 · 4MB each · 8MB total
- Pick one: up to 255 options; Score: 2–10 levels
- Released 2026-10-01

## Uses

- **Ticket and screenshot routing**: On a large volume of requests with screenshots, pick a team or a tool. See [Agent tool routing](https://system-one.dev/en/blog/agent-tool-routing).
- **Model routing**: First judge how hard the request is, then send it to a small or large model. See [Model routing](https://system-one.dev/en/blog/model-routing).
- **Batch moderation**: Read text and an image, then allow, block, or hand off from a yes/no probability. See [Agent guardrails](https://system-one.dev/en/blog/agent-guardrails).
- **High-frequency checks in an agent loop**: When every step must decide whether to stop or continue, use the lower-priced model to control cost. See [When an agent should stop](https://system-one.dev/en/blog/agent-stop-condition).

## Frequently asked questions

### How is Clef different from Clef Flash?

Clef Flash, Clef, and Clef Omni share the same request format and all accept text and images. Clef Flash is the cheapest and fits high-volume, cost-sensitive work. Clef has the highest rate; when Jev or Clef Flash is not good enough, compare Clef on the same data. Compare the rates in each page’s Model info. See [What is Clef](https://system-one.dev/en/models/clef).

### What inputs does Clef Flash accept?

Text (including JSON) and images. Image formats, count, and request-size limits are in Model info on this page.

### Does Clef Flash support Chinese?

Test Chinese results with your own data first.

### Is there a free allowance?

Billing is in credits. See Model info on this page for the rate. Details: [Pricing](https://system-one.dev/en/pricing). New accounts get 100 free credits on sign-up.

## Official sources

- [On this site: decision primitives](https://docs.system-one.dev/en/docs/primitives)
- [GET /v1/models](https://system-one.dev/v1/models)
- [All models](https://system-one.dev/en/models)

Last updated 2026-10-12

- [Open GET /v1/models](https://system-one.dev/v1/models)

- [Developer docs](https://docs.system-one.dev/en/docs/api#developer-details)

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