Spot GPUs at the market price,
with a ceiling you set.

Python

job = fx.jobs.create(
    image="ghcr.io/acme/train:latest",
    gpu="H200:8",
    capacity=fantasti.Spot(max_price=3.10),   # your ceiling, USD per GPU-hour
)
print(job.status)                             # blocked | placing | running

follow = fantasti.Spot(max_price="follow")    # no ceiling, pay the spot price

REST

// the "capacity" field takes one of four forms, on every product
{ "capacity": { "mode": "spot", "max_price": "follow" } }

{ "capacity": { "mode": "spot", "max_price": "3.10",
                "currency": "USD", "unit": "gpu_hour" } }

{ "capacity": { "mode": "on_demand" } }

{ "capacity": { "mode": "reserved", "reservation": "rsv_7d2k…" } }

YAML

# policy.yaml · applies to every request from team "research"
team: research
placement:
  gpus: [H100, H200, B200]
  fabric: infiniband            # multi-node jobs stay on one fabric
  regions: ["us-*"]
capacity:
  allow: [on_demand, spot, reserved]
  spot:
    max_price: { H100: 2.40, H200: 3.10 }   # USD per GPU-hour, your ceilings
limits:
  gpus: { H200: 32 }
  sandboxes: { concurrent: 200, max_ttl: 60m }
  spend: { monthly_usd: 40000 }
cost_center: research-llm