How it was made (CRANE)
CRANE is a training-free, parameter-editing weight merge that injects reasoning ability from a "Thinking" donor into a tool-disciplined Instruct / code base, while constraining the edit so the base model's output format and tool-calling behavior are preserved. It treats the Thinking − Instruct delta \(\delta = \theta_{\text{think}} - \theta_{\text{inst}}\) as a pool of candidate reasoning edits, and applies three composable stages per layer \(l\) and parameter component \(c\):
θmerged(l,c)=θinst(l,c)+Stage 3Πτ,q(l,c)GSP(α⋅Stage 2SCTG(c,l)⋅Stage 1T(δ(l,c)))

Three small calibration sets drive the stages — \(\mathcal{D}_R\) (reasoning transfer), \(\mathcal{D}_A\) (agent-behavior / tool-use preservation), and \(\mathcal{D}_F\) (format preservation):
- Stage 1 — Magnitude thresholding \(T(\delta)\). A deterministic median-magnitude threshold keeps only the larger (top-half) delta coordinates and rescales them by 2, discarding low-confidence noise.
- Stage 2 — Conservative Taylor Gate \(S_{\text{CTG}}\). From a signed, direction-aware score \(s_K(j) = -g_{K,j},\delta_j\) per calibration loss, CTG keeps the positive part of the per-coordinate minimum over the reasoning and agent-behavior objectives, \(p_j = [\min{s_R(j), s_A(j)}]+\) — rewarding a coordinate only when the edit helps both. These aggregate into the per-component, per-layer coefficient \(S{\text{CTG}}(c,l)\), scaled by the single global merge strength \(\alpha\).
- Stage 3 — Graduated Sigmoidal Projection (GSP). From the SVD of format-critical Instruct activations \(H_q = U_q\Sigma_q V_q^{\top}\), a smooth sigmoidal weight \(\mathbf{w}q\) (set by singular amplitude and threshold \(\tau\)) gives the projector \(\Pi{\tau,q}^{\text{GSP}}(\Delta_q) = \Delta_q - \Delta_q V_q \operatorname{diag}(\mathbf{w}_q) V_q^{\top}\), attenuating high-amplitude format directions so reasoning is injected without perturbing chat-template tokens, tool-call delimiters, or JSON/schema structure.
The result is a merge that gains planning / reflection / recovery reasoning while keeping the base agent's compact, tool-call-disciplined behavior — the entire merge is a closed-form edit of the Instruct weights, with no fine-tuning.
This checkpoint's recipe
This checkpoint merges Qwen/Qwen3-30B-A3B-Instruct-2507 (base) and Qwen/Qwen3-30B-A3B-Thinking-2507 (donor) with:
- Global injection strength — \(\alpha = 0.25\), multiplied by the per-component CTG coefficients, so the Thinking delta is added at roughly a quarter strength.
- Per-layer / per-component gating — attention, expert (FFN), norm, and router components each get their own \(S_{\text{CTG}}(c,l)\) coefficient, varying by layer index rather than a single flat scalar.
- GSP projector — a freshly rebuilt Qwen3-30B graduated-sigmoidal projector (sigmoid threshold \(\tau = 0.03\)) protects the format / tool-call subspace before injection.
Architecture
The merge preserves the standard Qwen3-30B-A3B (MoE) topology unchanged:
Table with columns: Property, Value| Property | Value |
|---|
| model_type | qwen3_moe |
| Architecture class | Qwen3MoeForCausalLM |
| Total params | ~30B |
| Active params | ~3B |
| hidden_size | 2048 |
| num_hidden_layers | 48 |
| num_experts | 128 |
| num_experts_per_tok | 8 |
| num_attention_heads | 32 |
A config_1m.json is also included for the extended long-context variant: it keeps the same rope_scaling (null) and max_position_embeddings (262144), but adds a dual_chunk_attention_config (dual chunk attention, original_max_position_embeddings = 131072 + sparse-attention settings) for longer-context inference.
Usage
import torchfrom transformers import AutoModelForCausalLM, AutoTokenizer model_id = "zmzfpc/crane-30b" tokenizer = AutoTokenizer.from_pretrained(model_id)model = AutoModelForCausalLM.from_pretrained( model_id, torch_dtype=torch.bfloat16, device_map="auto",) messages = [ {"role": "user", "content": "Write a Python function that returns the nth Fibonacci number."},] inputs = tokenizer.apply_chat_template( messages, add_generation_prompt=True, return_tensors="pt",).to(model.device) outputs = model.generate(inputs, max_new_tokens=512)print(tokenizer.decode(outputs[0][inputs.shape[-1]:], skip_special_tokens=True))
Requires a recent transformers with Qwen3-MoE support (transformers >= 4.51).
Citation / attribution
If you use this model or the CRANE method, please cite:
@misc{zhu2026crane, title = {CRANE: Constrained Reasoning Injection for Code Agents via Nullspace Editing}, author = {Zhu, Mingzhi and Merler, Michele and Pavuluri, Raju and Patterson, Stacy}, year = {2026}, eprint = {2605.14084}, archivePrefix= {arXiv}, primaryClass = {cs.SE}, url = {https://arxiv.org/abs/2605.14084}}
Project page: https://rpi-nsl.github.io/CRANE/ · Code: github.com/rpi-nsl/CRANE
Base models — built from two Apache-2.0 checkpoints:
License: Apache-2.0 (consistent with both base models and the CRANE code).