Credits

A credit is one vCPU-second of SimulationCraft runtime. A job running on 32 vCPU for 1 second costs 32 credits. Longer or wider jobs cost more.

For example, a 5-second single-target sim costs 160 credits at 32 vCPU. A 5-minute profileset-heavy sim at the same vCPU costs 9,600 credits.

#How credits are calculated

credits = runtime_seconds × vcpu_count

All jobs run on 32 vCPU, so credit cost scales only with runtime. You can view the current vCPU per job allocation in GET /simc/usage under limits.vcpuPerJob.

The runtime_seconds is wall-clock SimC execution time, rounded up to the nearest second. Only time spent running SimulationCraft counts. The following are not included:

• Queue time
• Worker setup (e.g. fetching the SimC build, staging inputs)
• Multi-stage orchestration
• Artifact collection and upload
• Platform overhead

A job that ran SimC for 4.2 seconds is billed as 5 seconds total. That total is the same whether the job ran immediately or sat in queue for 30 seconds with another 3 seconds of worker setup, orchestration, and upload.

#What consumes credits

If SimC ran, its runtime consumes credits. This includes:

• Jobs cancelled mid-run (charged for SimC runtime up to cancellation)
• Jobs where SimC crashes mid-execution (charged for runtime up to the crash)

Jobs interrupted by platform issues (e.g. VM preemption) are automatically retried, and only the successful run's runtime_seconds counts.

#Reservation

Credits are reserved at submission against your balance, based on the job's maximum possible cost (maxRuntimeSeconds × vCPU). When the job completes, actual usage is deducted from the reservation and the unused portion is released back to your balance.

A job submitted with maxRuntimeSeconds: 1800 on 32 vCPU reserves 57,600 credits. If SimC runs for 5 minutes, the job is billed 9,600 credits and the remaining 48,000 are released back on completion. Most jobs need far less headroom than this, as a 10-second sim costs 320 credits.

Set maxRuntimeSeconds close to your job's actual expected runtime, with enough headroom to absorb variance. Setting it too low risks the job being cancelled mid-run, which consumes credits for what ran with no usable result.

#Included credits

Each new account starts with 50,000 starter credits. Verified accounts receive 200,000 included credits each month. Both are issued as grants and appear in your Credits activity.

#Spending order

Spending is prioritized toward grants first (soonest-expiring used first), then purchased credits. See your Credits activity for the full record of grants, purchases, and consumption.