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MiniMax-M2

On-the-fly conversion: these weights are not mirrored as preconverted .weights.h5 under zeromodels/. from_weights("<variant>") downloads the original safetensors from the Hub and converts them in process on every load, because checkpoints this large are impractical to re-host. Pass cache_converted=True to keep the converted result and skip the download and conversion next time. See Loading Weights.

MiniMax's M2 Mixture-of-Experts LLM, ported to pure Keras 3. Unlike MiniMax-Text-01, M2 uses full attention throughout rather than the lightning / full hybrid, in front of a sparse expert bank.

The hub checkpoints ship in FP8 and are dequantized during conversion. Memory is governed by total parameters, not active ones.

See also minimax.md, minimax_m3_vl.md.

Variants

Load any of these with from_weights("<variant>").

Variant Hub
minimax-m2 MiniMaxAI/MiniMax-M2

API

MiniMaxM2Model

The decoder backbone, no LM head. Returns {"last_hidden_state": (batch, seq, embed_dim)}.

Arg Default Meaning
vocab_size 200064 token vocabulary size
embed_dim 3072 model width
mlp_dim 1536 MLP inner width
num_layers 62 decoder blocks
num_heads 48 query heads
num_kv_heads 8 key/value heads (GQA)
head_dim 128 per-head width
num_experts 256 expert count
num_experts_per_tok 8 experts routed per token
partial_rotary_factor 1.0 fraction of each head that gets rotated
rope_theta 5000000.0 rotary base frequency
norm_eps 1e-06 RMSNorm epsilon
tie_embeddings False reuse the embedding matrix as the LM head

MiniMaxM2TextGenerate

MiniMaxM2Model plus a (tied) LM head. Returns {"logits": (batch, seq, vocab_size)} and adds .generate(). Same constructor arguments as MiniMaxM2Model.

generate(
    input_ids,
    attention_mask=None,
    max_new_tokens=None,
    eos_token_id=None,
    sampler=None,
    seed=None,
    **prefill_inputs,
)
Arg Default Meaning
input_ids required (batch, seq) token ids
attention_mask None (batch, seq) 1 = keep, 0 = padding
max_new_tokens None tokens to generate
eos_token_id None stop token (defaults to the tokenizer's)
sampler None sampling strategy; greedy when unset
seed None seed for stochastic samplers

MiniMaxM2Tokenizer

Tokenizer on the tokenizers backend.

MiniMaxM2Tokenizer(hf_id=None, tokenizer_file=None)
Arg Default Meaning
hf_id None Hub repo to pull the tokenizer files from
tokenizer_file None explicit path to a tokenizer.json

Calling it returns {"input_ids", "attention_mask"}, padded across the batch. It accepts a plain string or a list of strings (a batch). This tokenizer has no chat template, so pass a prompt you have already rendered rather than a message list. Decode with .decode(ids) for one sequence or .batch_decode(ids) for a batch.

End-to-end example

Single input

import os

os.environ["KERAS_BACKEND"] = "torch"  # or "jax" / "tensorflow"

from zeromodels.models.minimax_m2 import MiniMaxM2TextGenerate, MiniMaxM2Tokenizer

model = MiniMaxM2TextGenerate.from_weights("minimax-m2")
tokenizer = MiniMaxM2Tokenizer.from_weights("minimax-m2")

inputs = tokenizer("Explain rotary embeddings in one sentence.")
outputs = model.generate(**inputs, max_new_tokens=64)

print(tokenizer.decode(outputs[0]))

Batch

Pass a list of strings. The tokenizer pads them and generate runs the batch together:

prompts = [
    "The capital of France is",
    "In one sentence, what is a transformer?",
    "Write a haiku about GPUs.",
]
inputs = tokenizer(prompts)  # {"input_ids": (3, seq), "attention_mask": (3, seq)}
outputs = model.generate(**inputs, max_new_tokens=64)

for text in tokenizer.batch_decode(outputs):
    print(text)

Backbone only

from zeromodels.models.minimax_m2 import MiniMaxM2Model

backbone = MiniMaxM2Model.from_weights("minimax-m2")
hidden = backbone(inputs)["last_hidden_state"]  # (batch, seq, embed_dim)

Loading from the Hub

Any Hub repo with this architecture works via the hf: prefix, including community fine-tunes:

model = MiniMaxM2TextGenerate.from_weights("hf:MiniMaxAI/MiniMax-M2")

Lower memory

Larger checkpoints load in bf16 or weight-only quantized. See quantization.md:

model = MiniMaxM2TextGenerate.from_weights(
    "minimax-m2", quantization="int8", load_dtype="bfloat16"
)