Context

The cookbook architecture-demos spec tracks OLMo as status: blocked. No prior aprender issue covers this loader; OLMo's distinguishing feature is full reproducibility — Allen AI ships training data and intermediate checkpoints, making it valuable as a teaching/research target.

Family

• Name: olmo
• Vendor: AllenAI
• HF architectures: OlmoForCausalLM, Olmo2ForCausalLM
• HF pattern: allenai/OLMo-*
• Reference checkpoints: allenai/OLMo-1B-hf, allenai/OLMo-7B-hf, allenai/OLMo-2-1124-7B

Acceptance criteria

• contracts/model-families/olmo.yaml exists with size_variants for 1B and 7B (covers both Olmo-1 and Olmo-2 architectures via Olmo2ForCausalLM)
• Loader handles OLMo-2's QK normalization (qk_norm boolean field)
• Discriminator distinguishes OLMo from Llama (OLMo has non_parametric_layer_norm or qk_norm)
• Inference smoke pass against OLMo-1B-hf (smallest variant)

Unblock impact

• Cookbook manifest flips from blocked to certified
• Adds a fully-reproducible-training family to the cookbook for research demos

Cookbook reference

• manifest.yaml entry — name: olmo block