Configurations

Configurations#

This page provides a comprehensive reference for all configuration parameters available in AReaL’s command-line interface. These parameters are defined using dataclasses and can be specified in YAML configuration files or overridden via command line arguments.

Usage#

Configuration files are specified using the --config parameter:

python -m areal.launcher --config path/to/config.yaml

You can override specific parameters from the command line:

python -m areal.launcher --config path/to/config.yaml actor.lr=1e-4 seed=42

For detailed examples, see the experiment configurations in the examples/ directory.

Table of Contents#

Core Experiment Configurations#

Training Configurations#

Inference Configurations#

Dataset#

System and Cluster Configurations#

Logging and Monitoring#

Others#

BaseExperiment Configuration#

Base configuration class for all experiment types with common settings.

Parameter	Type	Default	Description
`experiment_name`	string	Required	Name of the experiment (no ‘_’ or ‘/’). Required.
`trial_name`	string	Required	Name of the trial (no ‘-’ or ‘/’). Required.
`cluster`	`ClusterSpecConfig`	Required	Cluster specification. Mainly used by slurm.
`allocation_mode`	string	`""`	Pattern-based GPU parallel strategy allocation mode.
`seed`	integer	`1`	Random seed for reproducibility.
`enable_offload`	boolean	`False`	Whether to enable training offload using torch_memory_saver. This requires setting up the environment for TMS (e.g., via LD_PRELOAD).
`total_train_epochs`	integer	`1`	Total number of epochs to train the model.
`total_train_steps`	integer \| None	`None`	Terminate training after this number of steps. For benchmarking purposes only. None indicates normal training.
`total_train_n_seqs`	integer \| None	`None`	Terminate training after consuming this number of samples. For benchmarking purposes only. None indicates normal training.
`tokenizer_path`	string	`""`	Path to the tokenizer.
`train_dataset`	`TrainDatasetConfig`	Required	-
`valid_dataset`	`ValidDatasetConfig` \| None	`None`	-
`saver`	`SaverConfig`	Required	-
`evaluator`	`EvaluatorConfig`	Required	-
`stats_logger`	`StatsLoggerConfig`	Required	-
`perf_tracer`	`PerfTracerConfig` \| None	`None`	Performance tracer configuration. None means disabled.
`recover`	`RecoverConfig`	Required	-
`sglang`	`SGLangConfig`	Required	-
`vllm`	`vLLMConfig`	Required	-
`scheduler`	`SchedulerConfig`	Required	-

GRPO Configuration#

A dummy place holder of GRPO config for backward compatibility.

Parameter	Type	Default	Description
`experiment_name`	string	Required	Name of the experiment (no ‘_’ or ‘/’). Required.
`trial_name`	string	Required	Name of the trial (no ‘-’ or ‘/’). Required.
`cluster`	`ClusterSpecConfig`	Required	Cluster specification. Mainly used by slurm.
`allocation_mode`	string	`""`	Pattern-based GPU parallel strategy allocation mode.
`seed`	integer	`1`	Random seed for reproducibility.
`enable_offload`	boolean	`False`	Whether to enable training offload using torch_memory_saver. This requires setting up the environment for TMS (e.g., via LD_PRELOAD).
`total_train_epochs`	integer	`1`	Total number of epochs to train the model.
`total_train_steps`	integer \| None	`None`	Terminate training after this number of steps. For benchmarking purposes only. None indicates normal training.
`total_train_n_seqs`	integer \| None	`None`	Terminate training after consuming this number of samples. For benchmarking purposes only. None indicates normal training.
`tokenizer_path`	string	`""`	Path to the tokenizer.
`train_dataset`	`TrainDatasetConfig`	Required	-
`valid_dataset`	`ValidDatasetConfig` \| None	`None`	-
`saver`	`SaverConfig`	Required	-
`evaluator`	`EvaluatorConfig`	Required	-
`stats_logger`	`StatsLoggerConfig`	Required	-
`perf_tracer`	`PerfTracerConfig` \| None	`None`	Performance tracer configuration. None means disabled.
`recover`	`RecoverConfig`	Required	-
`sglang`	`SGLangConfig`	Required	-
`vllm`	`vLLMConfig`	Required	-
`scheduler`	`SchedulerConfig`	Required	-
`gconfig`	`GenerationHyperparameters`	Required	-
`eval_gconfig`	`GenerationHyperparameters` \| None	`None`	Generation hyperparameters for evaluation. If None, use gconfig.
`rollout`	`InferenceEngineConfig`	Required	-
`actor`	`PPOActorConfig`	Required	-
`ref`	`PPOActorConfig` \| None	`None`	-
`critic`	`PPOCriticConfig` \| None	`None`	-
`dynamic_bs`	boolean	`False`	Enable dynamic batch sizing in prepare_batch. When True, batch collection stops when (accepted + rejected) >= batch_size, returning only accepted results. This results in variable-sized batches of valid data.

PPO Configuration#

Configuration for Proximal Policy Optimization (PPO) reinforcement learning experiments.

Parameter	Type	Default	Description
`experiment_name`	string	Required	Name of the experiment (no ‘_’ or ‘/’). Required.
`trial_name`	string	Required	Name of the trial (no ‘-’ or ‘/’). Required.
`cluster`	`ClusterSpecConfig`	Required	Cluster specification. Mainly used by slurm.
`allocation_mode`	string	`""`	Pattern-based GPU parallel strategy allocation mode.
`seed`	integer	`1`	Random seed for reproducibility.
`enable_offload`	boolean	`False`	Whether to enable training offload using torch_memory_saver. This requires setting up the environment for TMS (e.g., via LD_PRELOAD).
`total_train_epochs`	integer	`1`	Total number of epochs to train the model.
`total_train_steps`	integer \| None	`None`	Terminate training after this number of steps. For benchmarking purposes only. None indicates normal training.
`total_train_n_seqs`	integer \| None	`None`	Terminate training after consuming this number of samples. For benchmarking purposes only. None indicates normal training.
`tokenizer_path`	string	`""`	Path to the tokenizer.
`train_dataset`	`TrainDatasetConfig`	Required	-
`valid_dataset`	`ValidDatasetConfig` \| None	`None`	-
`saver`	`SaverConfig`	Required	-
`evaluator`	`EvaluatorConfig`	Required	-
`stats_logger`	`StatsLoggerConfig`	Required	-
`perf_tracer`	`PerfTracerConfig` \| None	`None`	Performance tracer configuration. None means disabled.
`recover`	`RecoverConfig`	Required	-
`sglang`	`SGLangConfig`	Required	-
`vllm`	`vLLMConfig`	Required	-
`scheduler`	`SchedulerConfig`	Required	-
`gconfig`	`GenerationHyperparameters`	Required	-
`eval_gconfig`	`GenerationHyperparameters` \| None	`None`	Generation hyperparameters for evaluation. If None, use gconfig.
`rollout`	`InferenceEngineConfig`	Required	-
`actor`	`PPOActorConfig`	Required	-
`ref`	`PPOActorConfig` \| None	`None`	-
`critic`	`PPOCriticConfig` \| None	`None`	-
`dynamic_bs`	boolean	`False`	Enable dynamic batch sizing in prepare_batch. When True, batch collection stops when (accepted + rejected) >= batch_size, returning only accepted results. This results in variable-sized batches of valid data.

RW Configuration#

Configuration for Reward Model (RW) training experiments.

Parameter	Type	Default	Description
`experiment_name`	string	Required	Name of the experiment (no ‘_’ or ‘/’). Required.
`trial_name`	string	Required	Name of the trial (no ‘-’ or ‘/’). Required.
`cluster`	`ClusterSpecConfig`	Required	Cluster specification. Mainly used by slurm.
`allocation_mode`	string	`""`	Pattern-based GPU parallel strategy allocation mode.
`seed`	integer	`1`	Random seed for reproducibility.
`enable_offload`	boolean	`False`	Whether to enable training offload using torch_memory_saver. This requires setting up the environment for TMS (e.g., via LD_PRELOAD).
`total_train_epochs`	integer	`1`	Total number of epochs to train the model.
`total_train_steps`	integer \| None	`None`	Terminate training after this number of steps. For benchmarking purposes only. None indicates normal training.
`total_train_n_seqs`	integer \| None	`None`	Terminate training after consuming this number of samples. For benchmarking purposes only. None indicates normal training.
`tokenizer_path`	string	`""`	Path to the tokenizer.
`train_dataset`	`TrainDatasetConfig`	Required	-
`valid_dataset`	`ValidDatasetConfig` \| None	`None`	-
`saver`	`SaverConfig`	Required	-
`evaluator`	`EvaluatorConfig`	Required	-
`stats_logger`	`StatsLoggerConfig`	Required	-
`perf_tracer`	`PerfTracerConfig` \| None	`None`	Performance tracer configuration. None means disabled.
`recover`	`RecoverConfig`	Required	-
`sglang`	`SGLangConfig`	Required	-
`vllm`	`vLLMConfig`	Required	-
`scheduler`	`SchedulerConfig`	Required	-
`actor`	`TrainEngineConfig`	Required	-

SFT Configuration#

Configuration for Supervised Fine-Tuning (SFT) experiments.

Parameter	Type	Default	Description
`experiment_name`	string	Required	Name of the experiment (no ‘_’ or ‘/’). Required.
`trial_name`	string	Required	Name of the trial (no ‘-’ or ‘/’). Required.
`cluster`	`ClusterSpecConfig`	Required	Cluster specification. Mainly used by slurm.
`allocation_mode`	string	`""`	Pattern-based GPU parallel strategy allocation mode.
`seed`	integer	`1`	Random seed for reproducibility.
`enable_offload`	boolean	`False`	Whether to enable training offload using torch_memory_saver. This requires setting up the environment for TMS (e.g., via LD_PRELOAD).
`total_train_epochs`	integer	`1`	Total number of epochs to train the model.
`total_train_steps`	integer \| None	`None`	Terminate training after this number of steps. For benchmarking purposes only. None indicates normal training.
`total_train_n_seqs`	integer \| None	`None`	Terminate training after consuming this number of samples. For benchmarking purposes only. None indicates normal training.
`tokenizer_path`	string	`""`	Path to the tokenizer.
`train_dataset`	`TrainDatasetConfig`	Required	-
`valid_dataset`	`ValidDatasetConfig` \| None	`None`	-
`saver`	`SaverConfig`	Required	-
`evaluator`	`EvaluatorConfig`	Required	-
`stats_logger`	`StatsLoggerConfig`	Required	-
`perf_tracer`	`PerfTracerConfig` \| None	`None`	Performance tracer configuration. None means disabled.
`recover`	`RecoverConfig`	Required	-
`sglang`	`SGLangConfig`	Required	-
`vllm`	`vLLMConfig`	Required	-
`scheduler`	`SchedulerConfig`	Required	-
`actor`	`TrainEngineConfig`	Required	-

FSDPEngine Configuration#

Configuration for Fully Sharded Data Parallel (FSDP) training backend.

Parameter	Type	Default	Description
`wrap_policy`	`FSDPWrapPolicy` \| None	`None`	FSDP wrap policy, specifying model layers to wrap.
`offload_params`	boolean	`False`	Whether to offload FSDP parameters to CPU.
`memory_efficient_load`	boolean	`False`	Enable memory-efficient model loading. When enabled, model weights are initialized on CPU and only rank 0 loads pretrained weights, which are then broadcast to all ranks after FSDP sharding. This reduces peak GPU memory during initialization for large models. Note: For VLMs, rank 0 broadcast is not used; each rank loads weights independently on CPU.

FSDPWrapPolicy#

Policy configuration for FSDP model layer wrapping. None defaults to wrapping transformer decoder layers defined by transformers.

Parameter	Type	Default	Description
`transformer_layer_cls_to_wrap`	list of string \| None	`None`	A list of transformer layer names for FSDP to wrap.

MicroBatch Specification#

Specification for splitting micro-batches during training.

Parameter	Type	Default	Description
`n_mbs`	integer \| None	`1`	Number of micro-batches (or minimum number if max_tokens_per_mb is set). Used when max_tokens_per_mb is None or as minimum count
`granularity`	integer	`1`	Granularity of each micro-batch. Adjacent sequences are grouped by this size when dividing microbatches.
`max_tokens_per_mb`	integer \| None	`None`	Maximum tokens per micro-batch for each forward pass. When set, n_mbs becomes the minimum number of micro-batches.
`n_mbs_divisor`	integer	`1`	Divisor for the number of micro-batches. The final number of micro-batches will be adjusted to be divisible by this value.

Norm Configuration#

Configuration for reward/advantage normalization.

Parameter	Type	Default	Description
`mean_level`	string \| None	`"batch"`	Mean level for normalization. None for no mean normalization. Choices: `batch`, `group`, `None`
`mean_leave1out`	boolean	`False`	Whether to use leave-one-out average.
`std_level`	string \| None	`"batch"`	Standard deviation level for normalization. None for no std normalization. Choices: `batch`, `group`, `None`
`std_unbiased`	boolean	`True`	Whether to use unbiased standard deviation computation. Defaults to True (changed from False in v0.3.4).
`eps`	float	`1e-05`	The eps when dividing by standard deviation to avoid numerical issues.
`group_size`	integer	`1`	Group size for group-level normalization

Optimizer Configuration#

Configuration for model optimization during training.

Parameter	Type	Default	Description
`type`	string	`"adam"`	Optimizer type. Adam_bf16 currently only supported FSDP Engine. Choices: `adam`, `sgd`, `adam_bf16`
`lr`	float	`0.001`	Learning rate
`weight_decay`	float	`0.01`	Weight decay
`beta1`	float	`0.9`	Adam beta1 parameter. Only effective when optimizer_type is adam/adam_bf16
`beta2`	float	`0.999`	Adam beta2 parameter. Only effective when optimizer_type is adam/adam_bf16
`eps`	float	`1e-08`	Adam epsilon parameter. Only effective when optimizer_type is adam/adam_bf16
`min_lr_ratio`	float	`0.0`	Minimum learning rate ratio after annealing
`lr_scheduler_type`	string	`"constant"`	Learning rate scheduler type Choices: `linear`, `cosine`, `constant`
`warmup_steps_proportion`	float	`0.001`	Proportion of training steps for warmup
`offload`	boolean	`False`	Enable optimizer state offloading
`initial_loss_scale`	float	`4294967296`	Initial loss scaling factor
`min_loss_scale`	float	`1.0`	Minimum loss scaling factor
`loss_scale_window`	float	`5`	Window size for loss scaling adjustment
`hysteresis`	integer	`2`	Hysteresis (scaling factor) for loss scaling
`gradient_clipping`	float	`1.0`	Gradient clipping threshold

PPOActor Configuration#

Configuration for PPO actor model, a subclass of a TrainEngine.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`path`	string	`""`	Path to HuggingFace checkpoint
`attn_impl`	string	`"flash_attention_2"`	Attention implementation for huggingface transformers model. Choices: `flash_attention_2`
`init_from_scratch`	boolean	`False`	Initialize model weights randomly
`is_critic`	boolean	`False`	Whether to use a critic/reward model
`temperature`	float	`1.0`	Temperature during generation.
`mb_spec`	`MicroBatchSpec`	Required	-
`pad_to_maximum`	boolean	`False`	Whether to pad each microbatch to the length upper bound specified by mb_spec. Can reduce memory fragmentation but slows down training.
`disable_dropout`	boolean	`False`	Disable dropout layers during training
`gradient_checkpointing`	boolean	`False`	Enable gradient checkpointing
`dtype`	string	`"bfloat16"`	Parameter data type.
`grad_reduce_dtype`	string	`"float32"`	Gradient reduction data type.
`optimizer`	`OptimizerConfig` \| None	`None`	Optimizer configuration. None means no training.
`weight_update_mode`	string	`"xccl"`	Weight update backend type. Choices: `disk`, `xccl`
`fsdp`	`FSDPEngineConfig`	Required	-
`archon`	`ArchonEngineConfig`	Required	-
`megatron`	`MegatronEngineConfig`	Required	-
`use_lora`	boolean	`False`	Whether to use LoRA. Only support FSDP. Note that should be enabled together with vLLM/SGLang.
`lora_rank`	integer	`32`	lora rank
`lora_alpha`	integer	`16`	lora alpha
`target_modules`	list of string	Required	lora target_modules.
`peft_type`	string	`"lora"`	peft method type. Only LoRA is supported for now.
`enable_tree_training`	boolean	`False`	Enable tree training with flex attention module. Not supported for Archon engine yet.
`scheduling_spec`	`tuple`	Required	Train engine schedule specs. Can accept 1 or 2 SchedulingSpec: if 1 spec provided, it’s used for both worker and engine, engine is embedded in the worker; if 2 specs provided, first one is for worker, second one is for engine. Currently only used by the TrainController.
`scheduling_strategy`	`SchedulingStrategy`	Required	The scheduling strategy of this TrainEngine, either separation or colocation. Currently only used by the TrainController.
`ppo_n_minibatches`	integer	`4`	Number of minibatches for each PPO update
`eps_clip`	float	`0.2`	Clipping factor for policy ratio
`eps_clip_higher`	float \| None	`None`	Clipping factor (higher value) for policy ratio. Default is None. When eps_clip_higher is set (decoupled), eps_clip will be used as the lower value.
`c_clip`	float \| None	`None`	Dual clipping factor for policy ratio, must be > 1.0. None disables dual clipping.
`m2_threshold`	float \| None	`None`	The second momentum threshold for M2PO.
`reward_norm`	`NormConfig` \| None	`None`	Normalization configuration for rewards
`reward_scaling`	float	`1.0`	Reward scaling factor
`reward_bias`	float	`0.0`	Reward bias
`reward_clip`	float	`20.0`	Maximum absolute value for reward clipping
`overlong_reward_penalty`	boolean	`False`	Penalty for overlong sequences. Used within DAPO.
`overlong_tokens`	integer \| None	`None`	Number of tokens in the tail that will receive a penalty
`overlong_penalty_factor`	float \| None	`None`	Penalty factor for tokens in the tail
`mask_no_eos_with_zero`	boolean	`False`	Mask truncated generations (no EOS token) and exclude from training
`discount`	float	`1.0`	Discount factor for future rewards
`gae_lambda`	float	`1.0`	Lambda parameter for GAE
`adv_norm`	`NormConfig` \| None	`None`	Normalization configuration for advantages.
`kl_ctl`	float	`0.1`	KL divergence coefficient
`kl_estimator`	string	`"k1"`	KL divergence estimator Choices: `k1`, `k2`, `k3`
`use_sapo_loss`	boolean	`False`	Use SAPO loss (mutually exclusive with PPO clipping)
`sapo_tau_pos`	float	`1.0`	SAPO temperature for positive advantages
`sapo_tau_neg`	float	`1.05`	SAPO temperature for negative advantages
`recompute_logprob`	boolean	`False`	Recompute log probability and replace the log probability returned by inference.
`use_decoupled_loss`	boolean	`False`	Use the decoupled loss. Implicitly enables recompute_logprob.
`behav_imp_weight_cap`	float \| None	`None`	Filter out tokens where behav_imp_weight exceeds behav_imp_weight_cap when computing loss. Must be > 1.0. use_decoupled_loss must be true.
`importance_sampling_level`	string	`"token"`	Level at which to compute importance sampling ratios. ‘token’: per-token ratios (standard PPO). ‘sequence’: sequence-level geometric mean of per-token ratios (GSPO). Choices: `token`, `sequence`
`prox_logp_method`	string	`"recompute"`	Method for computing proximal policy log-probabilities in decoupled PPO. Only effective when use_decoupled_loss=True. Options: ‘recompute’ (default): Standard decoupled PPO, recompute proximal policy via forward pass. ‘loglinear’: Use log-linear interpolation to approximate proximal policy (skip forward pass). ‘metrics’: Like ‘recompute’, but also compute approximation metrics for evaluation. Choices: `recompute`, `loglinear`, `metrics`
`log_agent_stats`	boolean	`False`	Log statistics for agent trajectories
`log_agent_stats_keys`	list of string	Required	Keys for logging agent trajectory statistics
`max_new_tokens`	integer	`1024`	Maximum number of new tokens to generate

PPOCritic Configuration#

Configuration for PPO critic model, a subclass of a TrainEngine.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`path`	string	`""`	Path to HuggingFace checkpoint
`attn_impl`	string	`"flash_attention_2"`	Attention implementation for huggingface transformers model. Choices: `flash_attention_2`
`init_from_scratch`	boolean	`False`	Initialize model weights randomly
`is_critic`	boolean	`False`	Whether to use a critic/reward model
`temperature`	float	`1.0`	Temperature during generation.
`mb_spec`	`MicroBatchSpec`	Required	-
`pad_to_maximum`	boolean	`False`	Whether to pad each microbatch to the length upper bound specified by mb_spec. Can reduce memory fragmentation but slows down training.
`disable_dropout`	boolean	`False`	Disable dropout layers during training
`gradient_checkpointing`	boolean	`False`	Enable gradient checkpointing
`dtype`	string	`"bfloat16"`	Parameter data type.
`grad_reduce_dtype`	string	`"float32"`	Gradient reduction data type.
`optimizer`	`OptimizerConfig` \| None	`None`	Optimizer configuration. None means no training.
`weight_update_mode`	string	`"xccl"`	Weight update backend type. Choices: `disk`, `xccl`
`fsdp`	`FSDPEngineConfig`	Required	-
`archon`	`ArchonEngineConfig`	Required	-
`megatron`	`MegatronEngineConfig`	Required	-
`use_lora`	boolean	`False`	Whether to use LoRA. Only support FSDP. Note that should be enabled together with vLLM/SGLang.
`lora_rank`	integer	`32`	lora rank
`lora_alpha`	integer	`16`	lora alpha
`target_modules`	list of string	Required	lora target_modules.
`peft_type`	string	`"lora"`	peft method type. Only LoRA is supported for now.
`enable_tree_training`	boolean	`False`	Enable tree training with flex attention module. Not supported for Archon engine yet.
`scheduling_spec`	`tuple`	Required	Train engine schedule specs. Can accept 1 or 2 SchedulingSpec: if 1 spec provided, it’s used for both worker and engine, engine is embedded in the worker; if 2 specs provided, first one is for worker, second one is for engine. Currently only used by the TrainController.
`scheduling_strategy`	`SchedulingStrategy`	Required	The scheduling strategy of this TrainEngine, either separation or colocation. Currently only used by the TrainController.
`ppo_n_minibatches`	integer	`4`	Number of minibatches for each PPO update
`eps_clip`	float	`0.5`	Clipping factor for value loss
`mask_no_eos_with_zero`	boolean	`False`	Mask truncated generations (no EOS token) and exclude from training

TrainEngine Configuration#

Core configuration for model training, including optimization and backend settings.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`path`	string	`""`	Path to HuggingFace checkpoint
`attn_impl`	string	`"flash_attention_2"`	Attention implementation for huggingface transformers model. Choices: `flash_attention_2`
`init_from_scratch`	boolean	`False`	Initialize model weights randomly
`is_critic`	boolean	`False`	Whether to use a critic/reward model
`temperature`	float	`1.0`	Temperature during generation.
`mb_spec`	`MicroBatchSpec`	Required	-
`pad_to_maximum`	boolean	`False`	Whether to pad each microbatch to the length upper bound specified by mb_spec. Can reduce memory fragmentation but slows down training.
`disable_dropout`	boolean	`False`	Disable dropout layers during training
`gradient_checkpointing`	boolean	`False`	Enable gradient checkpointing
`dtype`	string	`"bfloat16"`	Parameter data type.
`grad_reduce_dtype`	string	`"float32"`	Gradient reduction data type.
`optimizer`	`OptimizerConfig` \| None	`None`	Optimizer configuration. None means no training.
`weight_update_mode`	string	`"xccl"`	Weight update backend type. Choices: `disk`, `xccl`
`fsdp`	`FSDPEngineConfig`	Required	-
`archon`	`ArchonEngineConfig`	Required	-
`megatron`	`MegatronEngineConfig`	Required	-
`use_lora`	boolean	`False`	Whether to use LoRA. Only support FSDP. Note that should be enabled together with vLLM/SGLang.
`lora_rank`	integer	`32`	lora rank
`lora_alpha`	integer	`16`	lora alpha
`target_modules`	list of string	Required	lora target_modules.
`peft_type`	string	`"lora"`	peft method type. Only LoRA is supported for now.
`enable_tree_training`	boolean	`False`	Enable tree training with flex attention module. Not supported for Archon engine yet.
`scheduling_spec`	`tuple`	Required	Train engine schedule specs. Can accept 1 or 2 SchedulingSpec: if 1 spec provided, it’s used for both worker and engine, engine is embedded in the worker; if 2 specs provided, first one is for worker, second one is for engine. Currently only used by the TrainController.
`scheduling_strategy`	`SchedulingStrategy`	Required	The scheduling strategy of this TrainEngine, either separation or colocation. Currently only used by the TrainController.

GenerationHyperparameters#

Controls text generation behavior for rollout.

Parameter	Type	Default	Description
`n_samples`	integer	`1`	Number of sequences to generate per prompt.
`max_new_tokens`	integer	`16384`	Maximum number of tokens to generate.
`min_new_tokens`	integer	`0`	Minimum number of tokens to generate.
`max_tokens`	integer	`32768`	Maximum number of tokens including prompt and generated tokens.
`greedy`	boolean	`False`	Whether to use greedy decoding (max probability).
`top_p`	float	`1.0`	Nucleus sampling probability threshold (0.0, 1.0].
`top_k`	integer	`100000000`	Number of highest probability tokens to consider.
`temperature`	float	`1.0`	Sampling temperature. Higher values increase diversity.
`stop_token_ids`	list of integer	Required	Stop generation when encountering these token IDs.
`ignore_eos`	boolean	`False`	Do not stop generation when EOS is encountered.
`skip_special_tokens`	boolean	`True`	Skip special tokens when decoding/displaying outputs.
`stop`	list of string \| None	`None`	One or multiple stop words. Generation will stop if one of these words is sampled.
`frequency_penalty`	float	`0.0`	Penalizes tokens based on their frequency in generation so far. Must be between -2 and 2 where negative numbers encourage repetition.
`lora_name`	string	`""`	Lora name to be used for this generation.
`use_beam_search`	boolean	`False`	Enable beam search in the vLLM engine. When enabled, sampling parameters like temperature, top-p, and top-k are auto ignored.

InferenceEngine Configuration#

Configuration for inference servers, including offpolicyness control.

Parameter	Type	Default	Description
`experiment_name`	string \| None	`None`	-
`trial_name`	string \| None	`None`	-
`fileroot`	string \| None	`None`	Root directory for logs and trajectory dumps.
`max_concurrent_rollouts`	integer \| None	`None`	Maximum number of concurrent rollouts to the inference engine. Defaults to consumer_batch_size.
`queue_size`	integer \| None	`None`	Input/Output queue size for async rollout.
`consumer_batch_size`	integer	`1`	Batch size for consuming rollouts from the queue.
`max_head_offpolicyness`	integer	`0`	Maximum off-policyness for the head. If the current version is more than this many versions behind, the request will not be accepted.
`enable_rollout_tracing`	boolean	`False`	Whether to output verbose tracing messages for each generation request.
`check_trajectory_format`	boolean	`False`	Whether to check the format of produced trajectories of a customized workflow. Useful when debugging the workflow in isolation. Should be False during RL training.
`schedule_policy`	string	`"round_robin"`	Request scheduling policy Choices: `round_robin`
`tokenizer_path`	string	`""`	Path to tokenizer for trajectory text decoding.
`dump_to_file`	boolean	`False`	Whether to dump the trajectories to files under fileroot.
`setup_timeout`	float	`300.0`	Timeout in seconds of connecting to remote servers or launching local servers.
`request_timeout`	float	`3600`	Timeout for HTTP requests.
`request_retries`	integer	`3`	Number of retries for failed requests.
`pause_grace_period`	float	`0.0`	The grace period after calling /pause_generation. Wait until all requests have been dropped.
`scheduling_spec`	`tuple`	Required	inference engine schedule specs. Can accept 1 or 2 SchedulingSpec: if 1 spec provided, it’s used for both worker and engine, engine is embedded in the worker; if 2 specs provided, first one is for worker, second one is for engine. Currently only used by the RolloutController.
`scheduling_strategy`	`SchedulingStrategy`	Required	The scheduling strategy of this TrainEngine, either separation or colocation. Currently only used by the RolloutController.
`use_lora`	boolean	`False`	Whether to use LoRA. Should be same as actors LORA option.
`openai`	`OpenAIProxyConfig` \| None	`None`	OpenAI proxy configuration (used when workflow is an agent workflow).

SGLang Configuration#

Configuration for SGLang runtime. Refer to:

sgl-project/sglang for detailed documentation.

Parameter	Type	Default	Description
`model_path`	string	`""`	-
`random_seed`	integer	`1`	-
`skip_tokenizer_init`	boolean	`False`	-
`disable_cuda_graph`	boolean	`False`	-
`disable_radix_cache`	boolean	`True`	-
`disable_cuda_graph_padding`	boolean	`False`	-
`enable_nccl_nvls`	boolean	`False`	-
`disable_outlines_disk_cache`	boolean	`False`	-
`disable_custom_all_reduce`	boolean	`False`	-
`disable_overlap_schedule`	boolean	`False`	-
`enable_mixed_chunk`	boolean	`False`	-
`enable_dp_attention`	boolean	`False`	-
`enable_ep_moe`	boolean	`False`	-
`enable_torch_compile`	boolean	`False`	-
`torch_compile_max_bs`	integer	`32`	-
`cuda_graph_max_bs`	integer \| None	`None`	-
`cuda_graph_bs`	list of integer \| None	`None`	-
`torchao_config`	string	`""`	-
`enable_nan_detection`	boolean	`False`	-
`enable_p2p_check`	boolean	`False`	-
`triton_attention_reduce_in_fp32`	boolean	`False`	-
`triton_attention_num_kv_splits`	integer	`8`	-
`num_continuous_decode_steps`	integer	`1`	-
`enable_memory_saver`	boolean	`False`	-
`allow_auto_truncate`	boolean	`False`	-
`attention_backend`	string \| None	`"fa3"`	-
`enable_multimodal`	boolean	`False`	-
`sampling_backend`	string \| None	`None`	-
`context_length`	integer \| None	`32768`	-
`mem_fraction_static`	float \| None	`0.9`	-
`max_running_requests`	integer \| None	`None`	-
`chunked_prefill_size`	integer \| None	`-1`	-
`max_prefill_tokens`	integer	`32768`	-
`schedule_policy`	string	`"lpm"`	-
`schedule_conservativeness`	float	`1.0`	-
`cpu_offload_gb`	integer	`0`	-
`dtype`	string	`"bfloat16"`	-
`kv_cache_dtype`	string	`"auto"`	-
`dp_size`	integer	`1`	-
`ep_size`	integer	`1`	-
`enable_lora`	boolean \| None	`None`	-
`max_lora_rank`	integer \| None	`None`	-
`lora_target_modules`	list of string \| None	`None`	-
`lora_paths`	list of string \| None	`None`	-
`max_loaded_loras`	integer	`1`	-
`max_loras_per_batch`	integer	`1`	-
`lora_backend`	string	`"triton"`	-
`log_level`	string	`"warning"`	-
`log_level_http`	string \| None	`"warning"`	-
`log_requests`	boolean	`False`	-
`log_requests_level`	integer	`0`	-
`show_time_cost`	boolean	`False`	-
`enable_metrics`	boolean	`True`	-
`decode_log_interval`	integer	`1`	-
`enable_multithread_load`	boolean	`False`	-

vLLM Configuration#

Configuration for vLLM runtime. Refer to:

https://docs.vllm.ai/en/stable/api/index.html for detailed documentation.

Parameter	Type	Default	Description
`model`	string	`""`	-
`seed`	integer	`1`	-
`skip_tokenizer_init`	boolean	`False`	-
`enforce_eager`	boolean	`False`	-
`dtype`	string	`"bfloat16"`	-
`distributed_executor_backend`	string	`"mp"`	-
`max_num_seqs`	integer	`256`	-
`block_size`	integer	`16`	-
`swap_space`	integer	`4`	-
`cpu_offload_gb`	float	`0`	-
`disable_sliding_window`	boolean	`True`	-
`max_model_len`	integer \| None	`32768`	-
`no_enable_chunked_prefill`	boolean	`False`	-
`no_enable_prefix_caching`	boolean	`True`	-
`gpu_memory_utilization`	float	`0.9`	-
`worker_extension_cls`	string	`"areal.engine.vllm_ext.vllm_worker_extension.VLLMWorkerExtension"`	-
`enable_sleep_mode`	boolean	`False`	-
`uvicorn_log_level`	string	`"warning"`	-
`enable_lora`	boolean	`False`	-
`lora_modules`	string	`""`	-

TrainDataset Configuration#

Configuration for training dataset loading and preprocessing.

Parameter	Type	Default	Description
`path`	string	Required	Path to the dataset. Can be a local path or a HuggingFace dataset name.
`type`	string	Required	Type of training method, e.g., ‘sft’, ‘rl’, etc.
`batch_size`	integer	`1`	Batch size for the dataloader
`shuffle`	boolean	`True`	Whether to shuffle the dataset
`pin_memory`	boolean	`False`	Pin memory for faster data loading (set True for GPU training)
`num_workers`	integer	`0`	Number of worker processes for data loading
`drop_last`	boolean	`True`	Drop the last incomplete batch
`max_length`	integer \| None	`None`	Maximum token length of sequences in dataset. Longer sequences are filtered out.

ValidDataset Configuration#

Configuration for validation dataset loading and preprocessing.

It has different default values with TrainDatasetConfig. shuffle and drop_last default to False.

Parameter	Type	Default	Description
`path`	string	Required	Path to the dataset. Can be a local path or a HuggingFace dataset name.
`type`	string	Required	Type of training method, e.g., ‘sft’, ‘rl’, etc.
`batch_size`	integer	`1`	Batch size for the dataloader
`shuffle`	boolean	`False`	Whether to shuffle the dataset
`pin_memory`	boolean	`False`	Pin memory for faster data loading (set True for GPU training)
`num_workers`	integer	`0`	Number of worker processes for data loading
`drop_last`	boolean	`False`	Drop the last incomplete batch
`max_length`	integer \| None	`None`	Maximum token length of sequences in dataset. Longer sequences are filtered out.

Cluster Specification Configuration#

Configuration for cluster specification and distributed computing setup.

Parameter	Type	Default	Description
`name_resolve`	`NameResolveConfig`	Required	Name resolving configuration.
`cluster_name`	string	`"local"`	Name of the cluster. Used to set specific environs.
`fileroot`	string	`"/tmp/areal/"`	Root for logs and checkpoints. Should be available on all nodes.
`n_nodes`	integer	`32`	The size of the cluster. Used to decide slurm hostname suffix.
`n_gpus_per_node`	integer	`8`	Number of GPUs per node (physical).

NameResolve Configuration#

Configuration for distributed name resolution and service discovery.

Parameter	Type	Default	Description
`type`	string	`"nfs"`	Type of the distributed KV store for name resolving. Choices: `nfs`, `etcd3`, `ray`
`nfs_record_root`	string	`"/tmp/areal/name_resolve"`	Record root for NFS name resolving. Should be available on all nodes.
`etcd3_addr`	string	`"localhost:2379"`	Address of the ETCD3 server.
`ray_actor_name`	string	`"ray_kv_store"`	Name of the distributed Ray KV store.

Evaluator Configuration#

Configuration for model evaluation scheduling and timing.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`fileroot`	string	Required	-
`freq_epochs`	integer \| None	`None`	Trigger frequency in epochs. None disables epoch-based saving.
`freq_steps`	integer \| None	`None`	Trigger frequency in steps. None disables step-based saving.
`freq_secs`	integer \| None	`None`	Trigger frequency in seconds. None disables time-based saving.

Recover Configuration#

Configuration for experiment recovery and fault tolerance.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`fileroot`	string	Required	-
`freq_epochs`	integer \| None	`None`	Trigger frequency in epochs. None disables epoch-based saving.
`freq_steps`	integer \| None	`None`	Trigger frequency in steps. None disables step-based saving.
`freq_secs`	integer \| None	`None`	Trigger frequency in seconds. None disables time-based saving.
`mode`	string	`"disabled"`	Recovery mode for the launcher. Options: ‘on’ or ‘auto’: Automatically recover from previous runs if recover info and checkpoints are available. ‘off’ or ‘disabled’: Never recover from previous runs.
`retries`	integer	`3`	Number of recovery retries when recovery is enabled.

Saver Configuration#

Configuration for model checkpoint saving scheduling and timing.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`fileroot`	string	Required	-
`freq_epochs`	integer \| None	`None`	Trigger frequency in epochs. None disables epoch-based saving.
`freq_steps`	integer \| None	`None`	Trigger frequency in steps. None disables step-based saving.
`freq_secs`	integer \| None	`None`	Trigger frequency in seconds. None disables time-based saving.

StatsLogger Configuration#

Configuration for experiment statistics logging and tracking services.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`fileroot`	string	Required	-
`wandb`	`WandBConfig`	Required	Weights & Biases configuration.
`swanlab`	`SwanlabConfig`	Required	SwanLab configuration.
`tensorboard`	`TensorBoardConfig`	Required	TensorBoard configuration. Only ‘path’ field required.

Swanlab Configuration#

Configuration for SwanLab experiment tracking and monitoring.

Parameter	Type	Default	Description
`project`	string \| None	`None`	-
`name`	string \| None	`None`	-
`config`	`dict` \| None	`None`	-
`logdir`	string \| None	`None`	-
`mode`	string \| None	`"disabled"`	-
`api_key`	string \| None	`None`	-

TensorBoard Configuration#

Configuration for TensorBoard logging and visualization.

Parameter	Type	Default	Description
`path`	string \| None	`None`	-

WandB Configuration#

Configuration for Weights & Biases experiment tracking.

Parameter	Type	Default	Description
`mode`	string	`"disabled"`	-
`wandb_base_url`	string	`""`	-
`wandb_api_key`	string	`""`	-
`entity`	string \| None	`None`	-
`project`	string \| None	`None`	-
`name`	string \| None	`None`	-
`job_type`	string \| None	`None`	-
`group`	string \| None	`None`	-
`notes`	string \| None	`None`	-
`tags`	list of string \| None	`None`	-
`config`	`dict` \| None	`None`	-
`id_suffix`	string \| None	`"train"`	-

ArchonEngine Configuration#

Configuration for Archon Engine training backend.

Parameter	Type	Default	Description
`attn_type`	string	`"varlen"`	Attention backend type. Choices: `varlen`, `sdpa`
`offload_params`	boolean	`False`	Whether to offload FSDP parameters to CPU.
`enable_compile`	boolean	`True`	Enable torch.compile for TransformerBlocks.
`ac_mode`	string	`"selective"`	Activation checkpointing mode. ‘memory_budget’ requires enable_compile=True. Choices: `none`, `full`, `selective`, `memory_budget`
`selective_ac_option`	string	`"op"`	Selective AC option: ‘op’ for op-level, or integer string (e.g., ‘2’) for every Nth layer.
`ac_memory_budget`	float	`0.5`	Memory budget for ‘memory_budget’ AC mode. 0.0 = minimum memory (max recompute), 1.0 = default behavior (no recompute).
`ac_preserve_rng_state`	boolean	`False`	Preserve RNG state during checkpointing for deterministic output. Enabling this may slow down training.
`ac_debug`	boolean	`False`	(Testing only) Capture AC debug information. Will be slower.
`pp_schedule`	string	`"Interleaved1F1B"`	Pipeline parallel schedule type. Choices: `1F1B`, `Interleaved1F1B`
`pp_layers_per_stage`	integer \| None	`None`	Number of transformer layers per (virtual) pipeline stage. If set, num_virtual_stages is calculated from num_layers. If None, stages are inferred from schedule type (1 stage/rank for 1F1B, 2 stages/rank for Interleaved1F1B).
`pp_first_stage_less_layers`	integer	`1`	Number of layers to reduce in the first pipeline stage. Accounts for embedding layer overhead.
`pp_last_stage_less_layers`	integer	`1`	Number of layers to reduce in the last pipeline stage. Accounts for output layer overhead.

DistributedDataParallel Configuration#

Configuration for Megatron’s DistributedDataParallel.

Refer to Megatron-LM documentation for details.

Parameter	Type	Default	Description
`grad_reduce_in_fp32`	boolean	`True`	-
`overlap_grad_reduce`	boolean	`False`	-
`overlap_param_gather`	boolean	`False`	-
`align_param_gather`	boolean	`False`	-
`use_distributed_optimizer`	boolean	`True`	-
`check_for_nan_in_grad`	boolean	`False`	-
`bucket_size`	integer \| None	`None`	-
`average_in_collective`	boolean	`False`	-
`fp8_param_gather`	boolean	`False`	-

FP8Engine Configuration#

Configuration for FP8 (8-bit floating point) training.

This configuration encapsulates all FP8-related parameters and can be reused across different engines (e.g., Megatron, FSDP). When None in the parent config, FP8 training is disabled.

Parameter	Type	Default	Description
`mode`	string	`"e4m3"`	FP8 precision mode. Options: ‘e4m3’ (uniform e4m3), ‘hybrid’ (e4m3 for activations/weights, e5m2 for output activation gradients).
`recipe`	string	`"delayed"`	FP8 scaling recipe. Options: ‘tensorwise’, ‘delayed’, ‘mxfp8’ (Blackwell only), ‘blockwise’.
`param`	boolean	`False`	Keep parameters in FP8 precision to save memory. Not all parameters will be converted to fp8; for example, biases will remain unchanged.
`margin`	integer	`0`	Margin for FP8 scaling factor computation.
`amax_history_len`	integer	`1`	Length of amax history window for scaling factor computation.
`amax_compute_algo`	string	`"most_recent"`	Algorithm for choosing amax value. Options: ‘max’ (largest in history window), ‘most_recent’.
`wgrad`	boolean	`True`	When False, override FP8 config and compute weight gradients in higher precision.
`dot_product_attention`	boolean	`False`	Use FP8 implementation of Dot Product Attention.
`multi_head_attention`	boolean	`False`	Use FP8 implementation of Multi Head Attention.
`tp_only_amax_red`	boolean	`False`	Reduce FP8 AMAX only in TP or TP-CP domain.
`first_last_layers_bf16`	boolean	`False`	Retain first and last N TransformerBlocks in BF16 instead of FP8.
`num_layers_at_start_in_bf16`	integer	`1`	Number of layers at start to keep in BF16 when first_last_layers_bf16 is True.
`num_layers_at_end_in_bf16`	integer	`1`	Number of layers at end to keep in BF16 when first_last_layers_bf16 is True.
`direct_convert`	boolean	`True`	Whether to use direct FP8 conversion during weight updates and save/load. When True, FP8 parameters are directly converted between TE FP8 and PyTorch FP8 without intermediate dequantization/quantization.

MegatronEngine Configuration#

Configuration for Megatron-LM training framework.

Refer to Megatron-LM documentation for implementation details.

Parameter	Type	Default	Description
`wrap_with_ddp`	boolean	`True`	-
`use_torch_fsdp2`	boolean	`False`	-
`use_custom_fsdp`	boolean	`False`	-
`ddp`	`DistributedDataParallelConfig`	Required	-
`virtual_pipeline_parallel_size`	integer	`1`	Virtual pipeline parallel size for Megatron interleaved schedule. Set to >1 to enable VPP. Default is 1 (disabled).
`overlap_param_gather_with_optimizer_step`	boolean	`False`	-
`use_precision_aware_optimizer`	boolean	`False`	-
`main_grads_dtype`	string	`"float32"`	-
`main_params_dtype`	string	`"float32"`	-
`exp_avg_dtype`	string	`"float32"`	-
`exp_avg_sq_dtype`	string	`"float32"`	-
`async_save`	boolean	`False`	-
`use_checkpoint_opt_param_scheduler`	boolean	`True`	-
`use_deterministic_algorithms`	boolean	`False`	-
`recompute_granularity`	string \| None	`"full"`	-
`recompute_method`	string \| None	`"uniform"`	-
`recompute_num_layers`	integer \| None	`1`	-
`distribute_saved_activations`	boolean \| None	`None`	-
`recompute_modules`	list of string \| None	`None`	-
`moe_router_dtype`	string \| None	`"fp32"`	-
`moe_shared_expert_overlap`	boolean	`False`	Enable overlapping between shared expert computations and dispatcher communications. Without this, the shared experts execute after the routed experts.
`moe_enable_deepep`	boolean	`False`	-
`moe_token_dispatcher_type`	string	`"alltoall"`	Type of token dispatcher. Options: ‘allgather’,’alltoall’ and ‘flex’.
`moe_permute_fusion`	boolean	`False`	Fuse token rearrangement ops during token dispatching.
`fp8_config`	`FP8EngineConfig` \| None	`None`	-

OpenAIProxy Configuration#

Configuration for OpenAI proxy when using agent workflows.

Parameter	Type	Default	Description
`mode`	string	`"inline"`	OpenAI proxy mode: ‘inline’ (in-process) or ‘subproc’ (subprocess). `inline` mode runs the provided agent workflow directly in the same process. It can use the provided `base_url` and `http_client` to reduce overhead. `subproc` mode launches a separate process to run the agent with `OPENAI_BASE_URL` environment variable, which offers more flexible deployment options at the cost of larger overhead. Choices: `inline`, `subproc`
`tool_call_parser`	string	`"qwen3"`	Parser for tool calls in model output.
`reasoning_parser`	string	`"qwen3"`	Parser for reasoning content ( tags).
`chat_template_type`	string	`"hf"`	Chat template type: ‘hf’ (standard) or ‘concat’ (multi-turn concatenation). Choices: `hf`, `concat`
`engine_max_tokens`	integer \| None	`None`	Maximum total tokens for the engine (prompt + completion).
`turn_discount`	float	`1.0`	Discount factor for multi-turn reward propagation.
`export_style`	string	`"individual"`	Export style: ‘individual’ (all interactions) or ‘concat’ (leaf nodes only). The ‘individual’ style exports each interaction (input-output-reward) step separately, and treats them as independent samples to train the model. The ‘concat’ style exports only the final concatenated trajectory from the root. It is only suitable for linear conversation histories without token mismatching (whether valid depends on the tokenizer). Choices: `individual`, `concat`
`subproc_max_workers`	integer	`4`	Maximum number of worker processes for subprocess mode execution pool.
`session_timeout_seconds`	integer	`3600`	Session timeout in seconds. Sessions inactive longer than this will be garbage collected.

PerfTracer Configuration#

Configuration for perf tracer emission.

Parameter	Type	Default	Description
`experiment_name`	string	Required	-
`trial_name`	string	Required	-
`fileroot`	string	Required	-
`enabled`	boolean	`False`	Explicitly enable or disable perf tracing. Set to true to capture perf traces.
`save_interval`	integer	`1`	Flush trace events to disk every N calls to save(step=…). A value of 1 writes on every step; values <= 0 fall back to 1.
`profile_steps`	list of integer \| None	`None`	List of step numbers at which to capture detailed profiling traces. If None, no detailed profiling traces are captured.
`session_tracer`	`SessionTracerConfig` \| None	`None`	Session tracing configuration.

Scheduler Configuration#

Configuration for worker scheduling. Used in the single-controller mode. Experimental.

Parameter	Type	Default	Description
`type`	string \| None	`None`	-
`endpoint`	string	`"http://localhost:8081"`	-
`deploy_mode`	string	`"separation"`	-
`functioncall_service_domain`	string	`"http://localhost:8080"`	-
`reward_functioncall_config`	`dict`	Required	-
`reward_model_path`	string	`""`	-
`reward_model_service_url`	string	`"http://localhost:30000/classify"`	-

Scheduling Specification#

Configuration class: SchedulingSpec

Parameter	Type	Default	Description
`cpu`	integer	`8`	Number of CPU cores required per GPU
`gpu`	integer	`0`	Number of GPU units required. Used only when allocating pods.
`mem`	integer	`32`	Amount of memory (GB) required per GPU
`port_count`	integer	`2`	Number of ports to expose
`image`	string	`"/storage/openpsi/images/areal-latest.sif"`	Docker/Singularity container image to use. Currently only used by Slurm. Will be potentially used by Kubernetes in the future.
`task_type`	string	`"worker"`	Task type (e.g., worker, engine) Choices: `worker`, `engine`
`env_vars`	`dict`	Required	Environment variables for the container
`cmd`	string \| None	`None`	Command to execute inside the container. Defaults to AReaL’s RPC server.
`srun_additional_args`	string	`"--unbuffered --mpi=pmi2 -K --chdir $PWD"`	Additional arguments to pass to the srun command. Only used by slurm.
`additional_bash_cmds`	list of string \| None	`None`	Additional bash commands to setup the container before running the torchrun command. Only used by slurm.
`container_type`	string	`"apptainer"`	Type of containers used in slurm Choices: `apptainer`, `none`
`mount`	string	`"/storage:/storage"`	Mount path for slurm.
`nodelist`	string \| None	`None`	sbatch/srun’s `--nodelist` option for slurm.
`exclude`	string \| None	`None`	sbatch/srun’s `--exclude` option for slurm.

SchedulingStrategy#

Configuration class: SchedulingStrategy

Parameter	Type	Default	Description
`type`	string	`"separation"`	- Choices: `separation`, `colocation`
`target`	string \| None	`None`	The target role to be colocated with
`fork`	boolean	`True`	When True with colocation, the target worker spawns a new process on the same node/GPUs instead of sharing its process. Provides process isolation while sharing GPU resources.

SessionTracer Configuration#

Configuration for per-session lifecycle tracing.

Parameter	Type	Default	Description
`enabled`	boolean	`False`	Enable per-session lifecycle tracing alongside perf events. When true, session metadata is captured to sessions.jsonl.
`flush_threshold`	integer	`256`	Flush session trace records once this many entries are ready. Values <= 0 fall back to 1.