HeartFlow Cloud

One API.
Multiple open models.

Power your AI apps with one API key and fund your usage with $HFAI.

Connect wallet Read the docs

01 / HOW IT WORKS

How it works. Three steps.

One balance for every model.
No separate account or key per model.

01 / TOP UP $HFAI
Top up with $HFAI tokens via Solana Pay, from any Solana wallet.
02 / BALANCE Credits
A prepaid balance, credited at a USD peg and drawn down as you use it.
03 / BUILD AI models
Chat in the app, or call the API from your own apps and agents.

02 / THE OFFER

Why HFAI Cloud

A growing set of open models behind
one endpoint, one key and one balance.

Sign in with SolanaNO EMAIL · NO PASSWORD

No email, no password. Your keys stay on your device.

Pay with $HFAIPREPAID CREDITS

Prepaid credits at a USD peg. A one-time purchase, not a subscription.

Pass-through pricingNO MARKUP

No markup, no tiers, no discounts — you pay the model’s list price.

Frontier modelsONE ENDPOINT

One endpoint, one API key, one balance.

03 / ONE KEY, EVERY MODEL

One key, every model.

Existing OpenAI-compatible clients work
by changing the base URL, the key and the model name.

One wallet, one balance, one key — with every model in the catalogue behind it.

Connect a Solana wallet and sign in with a signature instead of an account, then fund the balance with $HFAI. Mint one hfai_live_… API key, point any OpenAI-compatible client at https://api.heartflowai.net/v1, and the models are yours to call.

Switching models is a single edit: change the model string in the request. There is no new account, no card, and no new integration per model — and no second balance to top up when you move on to the next one.

04 / MODELS AND PRICING

Models and pricing

Per 1M tokens, charged from prepaid credits.
The catalogue is published live at the API.

HFAI Cloud model catalogue: context window and price per 1M tokens in US dollars. The live catalogue is published at https://api.heartflowai.net/v1/models.
Model	Context	Input / 1M	Output / 1M
DeepSeek V4.1 Flash	128K	$0.30	$1.20
GPT-OSS 120B FREE	128K	$0.15	$0.60
GPT-OSS 20B	128K	$0.07	$0.30
Gemma 4	128K	$0.14	$0.40
GLM 5.3 Flash	128K	$0.15	$0.50
MiniMax M3	128K	$0.60	$2.40
DeepSeek V4 Pro	1M	$1.32	$3.96
Nemotron 3 Ultra	256K	$0.10	$3.00
Kimi K2.6	256K	$0.95	$4.00

Prices are per 1M tokens in US dollars, charged from prepaid credits at the model’s list price with no markup. The row marked FREE is open to anonymous and zero-credit callers. The live catalogue and prices are published at https://api.heartflowai.net/v1/models.

How credits and fees work →

05 / QUICKSTART

Quickstart

Mint a key in the app, then send one request.
Any OpenAI-compatible client works the same way.

curl https://api.heartflowai.net/v1/chat/completions \
  -H "Authorization: Bearer hfai_live_…" \
  -H "Content-Type: application/json" \
  -d '{"model":"deepseek-v4-pro","messages":[{"role":"user","content":"Hello HFAI"}]}'

POST /v1/chat/completions — streaming chat, OpenAI-compatible.
GET /v1/models — the live model catalogue and pricing.

Replace hfai_live_… with a key from the app, and set the base URL to https://api.heartflowai.net/v1. The full reference lives in the chat completions docs.

ONE BALANCE · ONE API

Connect a wallet.
Send your first request.

Connect wallet Read the chat completions docs

One API.Multiple open models.