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[Proposal] Add Ouro LoopLM looped-depth adapter (OuroForCausalLM) #1470

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@jlarson4

Proposal

Add a TransformerBridge adapter for OuroForCausalLM (ByteDance Ouro / LoopLM), a Universal-Transformer-style looped model: one weight-tied layer stack iterated T times, plus a learned adaptive-exit halting gate.

Motivation

Ouro adds two surfaces no supported model has: weight-sharing across depth — the same L-layer stack is applied iteratively (default T=4), refining the hidden state in latent space; and a learned per-step exit/halting gate (ACT-style adaptive computation). Together they let researchers ask questions TL currently cannot pose: how an answer evolves/revises across loop iterations (cross-step logit lens, answer-flip analysis), what features drive halting (probe/patch the exit gate), and whether latent iterations are causally faithful vs post-hoc. It complements Huginn (RavenForCausalLM) by pairing the depth axis with adaptive-compute halting.

Gap scan (2026-06-25): ~15 models, ~288K downloads.

Scope note (medium-effort adapter)

Remote-code (auto_map to modeling_ouro), but the loop is a conventional block run in a for-loop — closer to a standard adapter than Huginn's variable-count recurrence. Remote-code loading is already supported (see openelm.py).

Pitch

Map the single shared stack iterated T times (expose each iteration's residual stream as a hookable step) plus the adaptive-exit gate head running parallel to the LM head.

  • Claude Code users can scaffold with /add-model-support ByteDance/Ouro-1.4B.
  • Register at the four sites listed in contributing.md.
  • Verify smallest-first: ByteDance/Ouro-1.4B, then ByteDance/Ouro-2.6B-Thinking.

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TransformerBridgeBug specific to the new TransformerBridge systemcomplexity-highVery complicated changes for people to address who are quite familiar with the codehelp wantedExtra attention is needednew-architectureThis card involves adding a new architecture .

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