FLUX Dev image generation
The popular 12B open-weight FLUX model: strong quality at a low price, with optional image-to-image.
POST /api/v1/nodes/flux-dev
Two ways to use FLUX Dev image generation
Way 1 · Pay per call (x402)
For AI agents, no sign-up
Your agent sends the request, gets a 402 with the exact price ($0.035), signs a USDC payment on Base and retries. Nothing is collected unless the call succeeds.
add TollNode to Claude Code, Cursor or Codex (once)
npx agentcash add https://tollnode.comor call it directly
npx agentcash@latest fetch https://tollnode.com/api/v1/nodes/flux-dev -m POST -b '{"prompt":"a retro-futuristic toll gate made of neon tubes, synthwave"}'Way 2 · Account + API key
For apps and teams
Create a free account, load a balance with USDC on Base, create an API key and call any node. Same prices; each successful call is deducted from your balance.
curl
curl -X POST https://tollnode.com/api/v1/nodes/flux-dev \
-H "Authorization: Bearer $TOLLNODE_API_KEY" \
-H "content-type: application/json" \
-d '{"prompt":"a retro-futuristic toll gate made of neon tubes, synthwave"}'Step-by-step, with code in JavaScript and Python: full guide for FLUX Dev image generation.
Input
| Field | Type | Notes |
|---|---|---|
| seed | integer | |
| image | string | Optional source image for image-to-image |
| prompt* | string | What to create or change |
| guidance | number | |
| aspect_ratio | enum | Aspect ratio, default 1:1 (1:1, 16:9, 21:9, 3:2, 2:3, 4:5, 5:4, 3:4, 4:3, 9:16, 9:21) |
| output_format | enum | (webp, jpg, png) |
| prompt_strength | number | How far to move from the source image |
Example response
{
"images": [
"https://tollnode.com/api/v1/files/00000000-0000-0000-0000-000000000000/0"
]
}FAQ
- What does the FLUX Dev image generation node return?
- The popular 12B open-weight FLUX model: strong quality at a low price, with optional image-to-image.
- How much does one call cost?
- $0.035 in USDC on Base, per successful call. No sign-up, subscription or API key.
- What happens if the call fails?
- You are not charged. TollNode checks your signed payment first, runs the node, and only collects the payment if the result is usable. A failed, empty or timed-out call is never settled, so there is nothing to refund.
- How does an AI agent pay?
- With x402. The first request returns HTTP 402 and the exact price. Any x402 wallet signs the USDC payment and retries automatically. In Claude Code or Cursor, run npx agentcash add https://tollnode.com once.
- Can I use an API key instead?
- Yes. Create a free account, add funds in USDC on Base, create an API key and send it as Authorization: Bearer. Each successful call is deducted from your balance at the same price; failed calls cost nothing.