Macaron-V1: Towards Open Continual Learning with Self-Improvement and Mixture-of-LoRA

Macaron-V1 is an open agent-model family for experiential intelligence: learning from experience in real environments and continuing to learn after deployment. It is organized around two system goals. Adaptation is pursued through recursive improvement of versioned model-harness pairs, where experience from one configuration is evaluated under an external contract and used to construct its successor. Collaboration is pursued via the Mixture-of-LoRA (MoL) architecture that freezes a base model, composes specialist LoRA adapters, and selects one LoRA per user turn. The flagship Macaron-V1-Venti (748B) combines a 744B GLM-5.2 base with four LoRAs for chat, agent, coding, and GenUI; the Qwen3.6-35B-based Macaron-V1-Tall (50B) uses the same design for local deployment. This report presents Macaron-V1 as a co-designed system spanning architecture, algorithms, and infrastructure. The MoL architecture supports continual learning through extensible LoRA specialists. The algorithm combines Model-Harness Co-design and recursive self-improvement loop, including the UI4A component-native GenUI harness, a stateful action substrate, versioned Harness Context Protocol contract, and the agentic RL framework MindForge.

Introduction. As pre-trained models mature, an increasing share of advances in capabilities such as agentic tool use and coding has come from post-training (OpenAI, 2026; Anthropic, 2026; Moonshot AI, 2025; GLM-5 Team, 2026). The effectiveness of post-training, however, is closely coupled to the environment in which a model is trained, evaluated, and deployed (Yao, 2025; Lee et al., 2026b; Karten et al., 2026). The data a model learns from, the tools it can use, the users it serves, and the interactions it must support jointly shape the behavior required of a deployed agent (Harrington et al., 2026; Karten et al., 2026; Lee et al., 2026b). These conditions vary across deployments and continue to evolve over time, as new knowledge becomes available, new domains emerge, and interaction state accumulates across episodes (Li et al., 2025a; Harrington et al., 2026; Jin et al., 2026; Lei et al., 2026).

Discussion / Conclusion. Adaptation is not the property of a single model; it is the property of the loop the model sits in (Silver and Sutton, 2025; Yao, 2025). The RSI cycle (Section 3.2) generates harder tasks, audits trajectories under a versioned harness configuration, evaluates candidate HCPs, and only then uses selected trajectories to update weights. The design description concerns this loop; the released checkpoint is one snapshot and does not demonstrate improvement across generations. Collaboration is not a multi-agent framework layered on top of a model; it is an architectural affordance. Because the base is shared and adapters are portable, the registry can admit specialists trained by different teams or personalized for different users on the same runtime (Mind Lab, 2026b; Lu et al., 2026). The Proxy’s routing interface is the proposed interoperability contract; this release tests only the four shipped specialists. Neither bet is settled by Macaron-V1. The design is inspectable in the released harness (https://github. com/MindLab-Research/Mixture-of-LoRA-Harness) and Macaron-V1-Venti weights (https://huggingface.