GLM 5.3
GLM-5.3 is Z.ai's flagship open-weights model for complex coding and long-horizon agentic tasks, served here as Modal's NVFP4 quantization: 753B total parameters with 40B active per token, a 1M-token context, always-on reasoning with low, high, and max effort levels, and Z.ai's GLM-5.3 License.
Model
GLM-5.3 shares its base model with GLM-5.2, so every gain comes from scaled post-training on long-horizon task environments. Architecturally it is a 78-layer Mixture-of-Experts with 256 routed experts plus one shared expert, 8 experts active per token, 40B active parameters out of 753B total, and DeepSeek Sparse Attention with IndexShare supporting a 1M-token context. Z.ai reports a 50% improvement over GLM-5.2 on its in-house Z.ai Code Bench, open-source state of the art on Terminal Bench 3.0 and Agents' Last Exam, and emergent cyber capability on vulnerability discovery and exploitation benchmarks. Reasoning is always on, with a reasoning_effort parameter that accepts low, high, or max.
This checkpoint is Modal's NVFP4 quantization of GLM-5.3, produced from Z.ai's BF16 release with NVIDIA Model Optimizer. Only the routed-expert linear layers are quantized to NVFP4; attention, the DSA indexer, shared experts, the MTP layer, embeddings, and the output head stay in BF16. The weights are released under Z.ai's GLM-5.3 License, inherited from the base model. Full details are in Z.ai's announcement and the model card.
Dedicated Endpoint
DocsA Dedicated Endpoint is your own deployment of GLM 5.3, on an inference stack that Modal tunes and autoscales. Bring fine-tuned weights if you have them. Compute is billed by the second, and only while it runs.
modal endpoint create --model modal-labs/GLM-5.3-NVFP4