Leap API
FLUX.3 APIBlack Forest Labs' model, through Leap
Black Forest Labs' newest image model, released on 2026-10-01, at 1K. One Leap key and one balance run it and every other model, priced per call in dollars.
First $5 top-up, no card fee.
- One key for every model
- Every call quoted first
- A failed call costs nothing
curl https://api.tryleap.ai/v1/generations \ -H "x-api-key: $LEAP_API_KEY" \ -H "content-type: application/json" \ -H "prefer: wait=60" \ -d '{ "model": "black-forest-labs/flux-3", "input": { "prompt": "A silk scarf in the wind on a ferry deck" } }' # Video often outlasts the wait and answers "queued" or "running".# Put its "id" in GENERATION_ID and read it again until it is done:# curl https://api.tryleap.ai/v1/generations/$GENERATION_ID -H "x-api-key: $LEAP_API_KEY"Set LEAP_API_KEY and send it. With prefer: wait=60 the answer holds the result when the call finishes within a minute; a longer one is read again by its ID.
- Model ID
- black-forest-labs/flux-3
- Price per call
- $0.065
- This call
- An image costs $0.065.
- First top-up
- A first top-up of $5, with no fee, covers 76 calls like it.
What it makes
Made with FLUX.3
Real FLUX.3 runs on Leap. Each one passed Leap's media quality check before it was shown.

“Theatrical key-art poster for an invented Nordic thriller titled SALT LINE. A lone woman in her fifties, Faroese, weathered face with windburned cheeks and pale eyes, grey-blond hair whipped by the wind, in a bright yellow oilskin fishing jacket, stands on a black basalt sea wall in the Faroe Islands as a storm wave explodes white behind her; she is small against the sea, and the turf-roofed houses of a cliff village sit high behind her. Desaturated slate blue and black, with the yellow jacket as the only colour. Typography: the title SALT LINE huge in a tall, condensed, bold sans serif in white across the upper third, tightly set; at the bottom the tagline "The sea keeps what it takes." and below it, small, "IN CINEMAS THIS NOVEMBER". Film grain, offset print texture, a real one-sheet composition with generous negative space. No other text.”

“Car commercial frame, aerial drone shot, early morning. The switchback road of the Passo Giau in the Italian Dolomites: grey limestone walls, larch trees turned gold, a sea of low cloud filling the valley below, first sun striking the peaks pink. A compact 1970s-inspired wedge-shaped two-door coupe in deep mustard yellow, with no badges and no logos, black steel wheels and pop-up headlights, exits a hairpin bend, its long morning shadow stretching across the asphalt. Shot from a drone thirty metres up and slightly behind, telephoto compression, the car small in the lower third of the frame. Palette: mustard yellow, limestone grey, larch gold, cold blue shadow. Kodak Portra 400 colour, fine grain. No readable text, no number plate.”
Inputs
What FLUX.3 takes
Only prompt is needed; everything else has a default. The same schema is public, with no key, at api.tryleap.ai/v1/public/models/black-forest-labs/flux-3.
MCP
Or let your agent call it.
Leap's MCP server lets Claude Code, Claude, VS Code and other MCP clients run FLUX.3, read its inputs and fetch the result, on your balance. Signing in happens in the browser, so there is no key to paste.
claude mcp add --transport http leap https://app.tryleap.ai/api/mcpClaude Code signs you in through the browser the first time it calls Leap.
curl -fsSL https://www.tryleap.ai/install.sh | shInstalls the Leap skill for every coding agent it finds: which endpoint to call, how to read a model's inputs, when to wait and when to poll.
Questions
FLUX.3 API questions
- How much does the FLUX.3 API cost?
- An image costs $0.065. That is the provider's list price plus our margin, the same as in the studio. POST /v1/quotes prices any input for free before you run it.
- Can I try the FLUX.3 API for free?
- No. API keys run on paid credit, so a key's first call needs a top-up, and quotes are free. An image costs $0.065. A first top-up of $5, with no fee, covers 76 default calls.
- Do I pay for calls that fail?
- No. The price is held when a call starts and charged only if it succeeds. A call that fails, or that the model's safety filter refuses, comes back with status "failed" and a failure_cause, and the hold is released.
- Is this Black Forest Labs' own API?
- No. Leap is a separate service: it sends your call to Black Forest Labs' model and gives you what it makes, so you need no Black Forest Labs account. One Leap key runs FLUX.3 and every other model in the catalog, from one balance.
- What are the rate limits?
- 600 requests a minute per API key and 300 a minute per IP address. A batch starts up to 50 calls in one request. A 429 says how long to wait in its Retry-After header.
- Can an AI agent call it?
- Yes. Leap's MCP server lets Claude Code, Claude, VS Code and other MCP clients find FLUX.3, read its inputs, run it and fetch the result on your balance. The client signs you in through the browser, so there is no key to paste.
Build with FLUX.3.
Keys run on paid credit, and the first top-up has no fee. The same key runs every model on Leap.
Get an API key