The Training API is currently in private preview. Request access before running this guide.
What you can run
SFT, DPO, and ORPO
Use cookbook recipes with LoRA or full-parameter configurations supported by the selected training shape.
RL and RFT
Run synchronous or asynchronous rollouts with custom rewards, losses, environments, and deployment sampling.
Distillation
Provision student and teacher resources for sampled reverse KL, top-k forward KL, and related workflows.
Custom loops
Use the Tinker-compatible training client directly when a maintained recipe does not express the required behavior.
Dedicated training steps
Step 1: Install the SDK and cookbook
Step 2: Choose the closest recipe
Fork the recipe and change only the task-specific data, loss, reward, rollout, evaluation, or configuration.
For a complete bounded SFT smoke using the bundled text-to-SQL dataset:
<shape>, then review the
model, shape, parameters, cost ceiling, and cleanup flags before running it.
Step 3: Choose the model and training shape
Use the live Training Shapes catalog. Pass the full shared shape ID and let the SDK resolve its validated version and linked deployment shape. Do not copy accelerator type, GPU count, image tag, or deployment-shape details into the config when the training shape owns them.Step 4: Configure stable run outputs
Record:- cookbook commit and installed SDK version;
- account, base model, recipe, and dataset;
- complete configuration, including defaults;
- training shape and linked deployment shape;
- stable trainer, output-model, and deployment IDs where the API exposes them;
- checkpoint cadence and resume policy;
- cost ceiling, success metric, and teardown policy.
Step 5: Provision the SDK-managed service
Cookbook recipes provision through the SDK-managed service. If you are writing a direct loop, follow the exactFiretitanServiceClient.from_firetitan_config(...) quickstart.
Provisioning happens on the first client creation. Capture service.trainer_job_id and every rollout or evaluation deployment ID immediately.
Step 6: Train and monitor
Run the forked recipe. Monitor:- trainer state and real optimizer-step progress;
- recipe metrics and W&B when configured;
- rollout success, reward distribution, and sampler latency for RL;
- checkpoints and deployment weight-sync state;
- quota, billing, and capacity separately.
Step 7: Save, sample, and evaluate
Save weights for the sampler, create or refresh the SDK-managed sampler, and evaluate the base and tuned policy on the same held-out set. For checkpoint and sampler details, see Saving and Loading and Training and Sampling.Step 8: Promote the selected checkpoint
List checkpoints from the control plane, choose a row marked promotable, validate the output model ID, and promote the full checkpoint resource name. Do not choose a winner from training loss alone. Use the agreed held-out metric or evaluator.Step 9: Deploy and prove serving
Create the final on-demand deployment, wait forREADY, then send a real request. READY without a successful response is not serving proof.
Fine-tuned LoRA adapters are served through an on-demand deployment, not the shared serverless inference catalog.
Step 10: Tear down
Set the recipe’s cleanup flags explicitly. Close the SDK-managed service intry/finally, then verify every trainer and deployment reached the requested final state. Resources are not deleted or scaled down unless the configuration requests it. Use the complete Cleanup and Teardown contract.
Checkpoint storage and promoted models can remain after compute teardown. Report them separately from billable trainer and deployment resources.