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Hosted Training updates every parameter of the model. Your run gets its own trainer, inference, and orchestrator pods, sized by the [deployment] block in your config. Runs dispatch on-demand — no reserved cluster required — and are billed per GPU-hour for as long as the pods are running.

Before you start

Models listed by prime train models are cached and start warm. On-demand runs can also download uncached Hugging Face models at startup, which adds billable time. Runs on a reserved cluster need the base model cached there, unless they load it from a volume. Both RL and Hosted SFT support /volume/... model paths with --volume; see Volume-hosted models.
This lists the models you can dispatch, plus an On-Demand Capacity table of purchasable GPU types with their current $/GPU-hour. If the model you want is missing, reach out to get it added. To see every GPU type you can dispatch on:
Dispatch is admitted against your wallet, so you also need on-demand enabled, a spendable balance, and a run that fits your per-run GPU cap — see Billing. Two platform limits apply by default: Reach out if your campaign needs more than that.

Config

Hosted Training runs use the native prime-rl config schema unchanged — no platform-specific fields. Size the run with a [deployment] block (see Launching a run). Minimal single-node example (1 trainer GPU + 1 inference GPU):
Multi-node example (2 train nodes + 2 inference nodes, each a full 8-GPU node):
Training and eval environments are arrays of source tables, each carrying a nested env block (env.taskset, env.agent.harness, env.agent.runtime). The older flat [[orchestrator.train.env]] shape with an id field was removed from prime-rl and is rejected at dispatch — see Environments for the current shape.
Multi-node runs broadcast weights over NCCL by default and auto-discover the cluster’s RDMA devices — no extra config needed.
See the prime-rl docs and config examples for the full schema.

Launching a run

Every RL config dispatches as a Hosted Training run — no flag needed. A [deployment] block sizes the run; without one, prime-rl’s own defaults apply, same as a local run:
On dispatch you get a run ID and a dashboard link:
Pass credentials with -e / --env-var or --env-file:
-e KEY reads the value from your shell, -e KEY=VALUE sets it inline, and --env-file path/to/.env loads a whole file. Every key you pass is written to a per-run secret and projected onto the trainer, inference, orchestrator, and env-server pods, so an environment that needs a third-party API key can read it straight from the process environment. WANDB_API_KEY and HF_TOKEN are recognized and routed to their own fields. A few constraints on the secret map:
WANDB_API_KEY is required for the [wandb] block to take effect — without it the block is stripped and the run trains without W&B logging.
Two dispatch-level knobs control the dispatch. Both accept a CLI flag or a top-level TOML key, and the flag wins: Checkpointing is off by default. To keep model weights, add a [ckpt] block, create a volume, and pass its name with --volume. Checkpoints live at runs/<runId>/checkpoints/. The run directory is saved to cloud storage when the run ends; keep_interval and keep_last are optional retention settings. See Checkpoint settings.

Run lifecycle

A dispatched run moves through:
  • QUEUED — no cluster has GPU headroom yet. The run is admitted and promoted automatically as capacity frees; you don’t need to resubmit.
  • PULLING_IMAGE — pods are scheduled and pulling the prime-rl image. This is multiple GB and can take many minutes on a cold node. It’s expected, not a stall.
Config errors (bad schema, uncached model, oversized deployment) are caught synchronously and fail the dispatch immediately with a reason, before any GPU is reserved. Stop a run early to release the cluster:
When a run reaches a terminal state, its cluster resources are torn down automatically. Orchestrator logs are captured to the run record first, but trainer, inference, and env-server pod logs go away with the pods — pull anything you need while the run is live. Metrics, samples, distributions, and progress are persisted and stay available in the dashboard. Trace uploads have separate pricing and workspace controls; see Managing traces for viewing, downloading, and deleting them. Older legacy samples are subject to the November 6 storage retirement.

Monitoring

A Hosted Training run has several distinct components. Pick which one to read with -c / --component:
List the orchestrator and env-server components for a run:
Follow and filter with -f, --search, --regex, --level, and --since. See Monitoring for details. The dashboard shows reward curves, rubric scores, and individual rollouts at https://app.primeintellect.ai/dashboard/training/<run-id>.

End-to-End Run

Step-by-step walkthrough of a complete run, from baseline eval to results.

prime-rl Configuration

Full reference for the underlying training framework config schema.