VARIANT · Black Forest Labs / Flux 2

Flux 2 flux-2-flex-text-to-image API

Same API key, same model skill workflow — switch variants by changing one model ID.

Operational · image · Commercial OK

runapi.ai

curl -X POST https://runapi.ai/api/v1/flux_2/text_to_image \
  -H "Authorization: Bearer $RUNAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "flux-2-flex-text-to-image",
  "prompt": "Generate a photorealistic studio portrait of an astronaut holding a cat, dramatic rim lighting, 8K detail."
}'

import { Flux2Client } from "@runapi.ai/flux-2";

const client = new Flux2Client();
const result = await client.textToImage.run({
    model: "flux-2-flex-text-to-image",
    prompt: "Generate a photorealistic studio portrait of an astronaut holding a cat, dramatic rim lighting, 8K detail.",
});

require "runapi/flux_2"

client = RunApi::Flux2::Client.new
result = client.text_to_image.run(
    model: "flux-2-flex-text-to-image",
    prompt: "Generate a photorealistic studio portrait of an astronaut holding a cat, dramatic rim lighting, 8K detail."
)

npx skills add runapi-ai/flux-2 -g

# Claude Code
claude mcp add runapi -s user -- npx -y @runapi.ai/mcp

# Codex
codex plugin install runapi-mcp@agents

# Cursor / Windsurf / VS Code
npx @runapi.ai/mcp init cursor

@runapi.ai/flux-2 v1

Switch variant

flux-2-flex-remix-image flux-2-pro-remix-image flux-2-pro-text-to-image

OVERVIEW

flux-2-flex-text-to-image targets the sweet spot of quality and cost within the Flux 2 family.

Pay-per-call pricing in USD
Failed generations not charged
Streaming when supported by the model
Schema-validated tool calls

PRICING

Pricing

Failed generations are not charged

Text to image

$0.14-$0.24 / image

Output resolution: 1k $0.14

Output resolution: 2k $0.24

SPEC SHEET

Technical details

Model ID	flux-2-flex-text-to-image
Provider	Black Forest Labs
Modality	image
Task type	asynchronous
Billing unit	call
API endpoint	/api/v1/flux_2/text_to_image
Commercial license	Yes — included via API
Status	Operational

SKILLS

Model skill — flux-2-flex-text-to-image

Install the skill once, then use the variant ID from this page while building.

# Install the model skill for app development workflows
npx skills add runapi-ai/flux-2 -g

Installs docs, schemas, pricing context, and setup notes into your developer workspace.

Or use this setup request in your coding tool:

Install the Flux 2 skill for this app:

1. Add runapi-ai/flux-2 with the skills installer.
2. Load SKILL.md in this workspace.
3. Use its docs, schemas, pricing notes, and setup steps when adding model features.
4. Confirm the install path when done.

HOW IT WORKS