Scope: This guide covers the Atlas training stack (Hydra configs, wrappers, optimization recipes). For the SDK runtime YAML, see the
SDK Configuration Reference
.Directory Quick Reference
Tip: Start with
wrappers/
to plug Atlas into your agent, then explore optimize/
for GEPA runs or run/
for full training jobs. The deeper directories (model/
, trainer/
) are for advanced customisation.Wrapping Your Agent (wrappers/)
- HTTP API
- Python Function
- CLI Command
Optimization & Datasets
configs/optimize/
– GEPA wrappers, vLLM clients, batching options.configs/data/
– Dataset definitions (arc_atlas_rl.yaml
,arc_atlas_sft.yaml
). Adjustmax_train_samples
, preprocessing, or add new splits.configs/rim_config.yaml
– Reward system selections used by both runtime and training.
Reward Design
for guidance on judges, variance thresholds, and escalation strategies.
Hydra Composition Deep Dive
Hydra composes experiment recipes from reusable building blocks.Layer Breakdown
Layer | Purpose | Example Files | When to Modify |
---|---|---|---|
train.yaml | Global defaults | Single file | Rarely – system-wide changes only |
run/*.yaml | Experiment recipes | teacher_rcl.yaml , teacher_sft.yaml | New experiment types |
model/*.yaml | Model specifications | qwen3_8b.yaml , llama3_8b.yaml | Adding new architectures |
data/*.yaml | Dataset configs | arc_atlas_rl.yaml , arc_atlas_sft.yaml | New datasets or preprocessing |
trainer/*.yaml | Algorithm settings | teacher_grpo.yaml , sft.yaml | Tweaking GRPO/SFT defaults |
trainer/reward/*.yaml | Reward presets (Hydra _global_ group) | rim_teaching.yaml | Swap reward bundles or create new ensembles |
Example: configs/run/teacher_rcl.yaml
Base structure
Base structure
_self_
keeps local settings at the top.trainer: teacher_grpo
trainer: teacher_grpo
Trainers API
.model: qwen3_8b
model: qwen3_8b
data: arc_atlas_rl
data: arc_atlas_rl
reward: rim_teaching
reward: rim_teaching
rim_config.yaml
.Customisation Patterns
Command-line Overrides
Creating New Configurations
1
Pick the layer
New model →
configs/model/
• New dataset → configs/data/
• New experiment → configs/run/
.2
Copy a template
3
Edit the template
4
Reference it in run config
Multi-GPU Scaling
- Single GPU
- 4 GPUs
- 8 GPUs
Common Scenarios
Memory-Constrained GPUs
Fast Iteration Mode
Production Training
Debugging Config Issues
hydra.verbose=true
to see each included file. If composition fails, confirm the path exists and the file is in the defaults list.