base_model when starting a run.
Every Baseten workspace can train models up to Qwen3.8-27B, which supports sequences up to 262,144 tokens. To train larger models or run more training sessions at once, request more access.
Models
Some models restrict the available loss functions by configuration. GLM 5.3 runs long contexts with context parallelism and router replay (R3) enabled, and in that configuration
cross_entropy and dpo are unavailable. See Loss functions for the full list.
List supported models
Use Get server capabilities to list models and sequence lengths through the API. Set your workspace API key asBASETEN_API_KEY:
max_seq_len), and sequence length enabled for your workspace (max_enabled_seq_len). Use use_case=rl to list models for reinforcement learning.
Pass a model to Loops
Pass the table value verbatim asbase_model through any of the following entry points:
- The Python SDK, using
ServiceClient.create_lora_training_client(base_model=...). See the Loops quickstart. - The HTTP API, using
POST /v1/loops/trainers. - The CLI, using
baseten loops run create --base-model <base_model>, which provisions a session, run, and paired sampler in one call.
2qjl22w with the session.id returned by POST /v1/loops/sessions:
Request more access
Use the Loops request form for larger models, longer sequences, more concurrent runs, or a model that isn’t listed. Include:- Your workspace name and the model’s Hugging Face repo ID.
- What you’re training and whether you need supervised fine-tuning or reinforcement learning.
- The maximum sequence length and number of concurrent runs you need.
- When you need the capacity.