--- description: FLUX.2 [flex] is Black Forest Labs' fine-grained control variant of FLUX.2 — exposes tunable inference steps, guidance, and prompt upsampling for typography-heavy and production workflows. title: FLUX.2 [flex] image: https://developers.cloudflare.com/og-docs.png --- [Skip to content](#main-content) > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/llms.txt > Use this file to discover all available pages before exploring further. ![Black Forest Labs logo](https://developers.cloudflare.com/_astro/blackforestlabs.Ccs-Y4-D.svg) # FLUX.2 \[flex\] Text-to-Image • Black Forest Labs Copy as Markdown|[View as Markdown](https://developers.cloudflare.com/ai/models/black-forest-labs/flux-2-flex/index.md)|[Agent setup](https://developers.cloudflare.com/agent-setup/) `black-forest-labs/flux-2-flex` * Third-party FLUX.2 \[flex\] is Black Forest Labs' fine-grained control variant of FLUX.2 — exposes tunable inference steps, guidance, and prompt upsampling for typography-heavy and production workflows. | Model Info | | | ----------------- | ------------------------------------------------------------------------------------------------------------------------------- | | Terms and License | [link ↗](https://blackforestlabs.ai/terms-of-service/) | | More information | [link ↗](https://blackforestlabs.ai/) | | Pricing | [View pricing in the Cloudflare dashboard ↗](https://dash.cloudflare.com/?to=/:account/ai/models/black-forest-labs/flux-2-flex) | ## Usage ```ts const response = await env.AI.run( 'black-forest-labs/flux-2-flex', { prompt: "Samsung Galaxy S25 Ultra product advertisement, 'Ultra-strong titanium' headline, close-up of phone edge showing titanium frame, dark gradient background, clean minimalist tech aesthetic", }, ) console.log(response) ``` ```bash curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "black-forest-labs/flux-2-flex", "input": { "prompt": "Samsung Galaxy S25 Ultra product advertisement, '\''Ultra-strong titanium'\'' headline, close-up of phone edge showing titanium frame, dark gradient background, clean minimalist tech aesthetic" } }' ``` ![Typography & Design](https://examples.aig.cloudflare.com/black-forest-labs/flux-2-flex/typography-design.jpeg) ```json { "state": "Completed", "result": { "image": "https://examples.aig.cloudflare.com/black-forest-labs/flux-2-flex/typography-design.jpeg" }, "gatewayMetadata": { "keySource": "Unified" } } ``` ## Examples **High Detail Generation** — Crank steps and guidance for maximum detail when latency is not the priority ```ts const response = await env.AI.run( 'black-forest-labs/flux-2-flex', { prompt: 'A detailed oil painting portrait of a Renaissance nobleman with intricate lace collar', guidance: 7.5, steps: 50, }, ) console.log(response) ``` ```bash curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "black-forest-labs/flux-2-flex", "input": { "prompt": "A detailed oil painting portrait of a Renaissance nobleman with intricate lace collar", "guidance": 7.5, "steps": 50 } }' ``` ![High Detail Generation](https://examples.aig.cloudflare.com/black-forest-labs/flux-2-flex/high-detail-generation.jpeg) ```json { "state": "Completed", "result": { "image": "https://examples.aig.cloudflare.com/black-forest-labs/flux-2-flex/high-detail-generation.jpeg" }, "gatewayMetadata": { "keySource": "Unified" } } ``` **Fast Draft** — Fast draft with prompt upsampling disabled — preserves the literal prompt ```ts const response = await env.AI.run( 'black-forest-labs/flux-2-flex', { prompt: 'A simple line sketch of a mountain landscape', prompt_upsampling: false, steps: 10 }, ) console.log(response) ``` ```bash curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \ --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "model": "black-forest-labs/flux-2-flex", "input": { "prompt": "A simple line sketch of a mountain landscape", "prompt_upsampling": false, "steps": 10 } }' ``` ![Fast Draft](https://examples.aig.cloudflare.com/black-forest-labs/flux-2-flex/fast-draft.jpeg) ```json { "state": "Completed", "result": { "image": "https://examples.aig.cloudflare.com/black-forest-labs/flux-2-flex/fast-draft.jpeg" }, "gatewayMetadata": { "keySource": "Unified" } } ``` ## Parameters prompt `string`requiredText prompt for image generation or editing. seed `integer`minimum: \-9007199254740991maximum: 9007199254740991Optional seed for reproducible generation. width `integer`minimum: 64maximum: 9007199254740991Width of the generated image in pixels (minimum 64). Omit to let BFL pick. height `integer`minimum: 64maximum: 9007199254740991Height of the generated image in pixels (minimum 64). Omit to let BFL pick. safety\_tolerance `integer`minimum: 0maximum: 5Tolerance for input/output moderation. 0 is the strictest, 5 the most permissive. Defaults to 2. output\_format `string`enum: jpeg, png, webpOutput image format. Defaults to jpeg. ▶input\_images\[\] `array`maxItems: 8Up to 8 reference images for editing or multi-image composition. Each entry is an HTTPS URL or a data:image/...;base64,... URI. prompt\_upsampling `boolean`Whether BFL should expand short prompts before generation. Defaults to true on flex. guidance `number`minimum: 1.5maximum: 10Classifier-free guidance scale (1.5–10). Higher values follow the prompt more strictly at the cost of realism. steps `integer`minimum: 1maximum: 50Number of denoising steps (1–50). Higher steps yield more detail at the cost of latency. image `string`format: uriURL to the generated image ## API Schemas (Raw) Input Output Was this helpful? 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Build, secure, and scale without managing infrastructure","url":"https://www.cloudflare.com/","sameAs":["https://github.com/cloudflare","https://www.linkedin.com/company/cloudflare","https://x.com/cloudflare"],"logo":{"@type":"ImageObject","url":"https://developers.cloudflare.com/logo.svg"},"address":{"@type":"PostalAddress","streetAddress":"101 Townsend St","addressLocality":"San Francisco","addressRegion":"CA","postalCode":"94107","addressCountry":"US"},"contactPoint":[{"@type":"ContactPoint","contactType":"Customer Support","url":"https://support.cloudflare.com/","availableLanguage":["English"]},{"@type":"ContactPoint","contactType":"Sales","url":"https://www.cloudflare.com/contact/","availableLanguage":["English"]}]},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"}} ```