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Why AI Agents Need Million-Token Context — Thomas Wolf & Olive Song, MiniMax

7.2K views · Sep 04, 2026 · 20:48 min · Watch on YouTube ↗
Takeaway

Efficient sparse attention can make long context more practical for agents that combine sustained tool use, coding, and multimodal inputs.

Summary

  • Olive Song describes MiniMax M3 as a multimodal agentic model with roughly 400 billion total parameters, 20 billion active parameters, and a one-million-token context window.
  • MiniMax Sparse Attention uses an indexing branch to select relevant context blocks and a sparse-attention branch to compute over those selections.
  • Long context is motivated by extended agent interactions and accumulating tool responses, alongside coding and image/video understanding.
  • Song describes an internally open research process in which staff propose improvements and assemble project teams; she credits an intern with the sparse-attention architecture work.
minimaxsparse-attentionlong-context
Original description
An intern designed the sparse-attention architecture behind MiniMax M3. That detail comes after Olive Song explains the larger problem the team was trying to solve: short context windows aren’t enough when agents must work across long conversations, tool responses and complex environments. M3 combines a functional one-million-token context window with coding, agentic and multimodal capabilities, allowing it to understand text, images and video within the same model.

Thomas Wolf and Olive Song unpack how MiniMax made that context window efficient, why the company trained M3 as multimodal from its very first step and what happens when that training goes wrong. They also discuss MiniMax’s open research culture, products used by hundreds of millions of people, the role of community feedback in improving open-source models and the internal agent harnesses accelerating the company’s own research. By the end, M3 is no longer just the model being discussed—it is already helping the team build M3.1.

About Thomas Wolf

Thomas Wolf is the co-founder and Chief Science Officer of Hugging Face, the open platform and community for building, sharing and collaborating on machine learning models, datasets and applications.

About Olive Song
Olive Song is the RL Lead at MiniMax, where she works on the research and training behind frontier open-source models including MiniMax M3.

Recorded at the AI Engineer World’s Fair in San Francisco. Stay up to date on our upcoming events and content by joining our newsletter here: https://www.ai.engineer/newsletter

Timestamps:
0:00 - Introduction
0:39 - The race between the leading open-source models
2:34 - MiniMax M3: coding, vision and one million tokens
3:46 - Why agents need longer context windows
6:22 - From GPT-2’s 1,024 tokens to million-token models
7:30 - The intern who designed MiniMax’s sparse attention
8:29 - How research projects work inside MiniMax
10:01 - Training a multimodal model from the first step
13:09 - Going beyond one trillion parameters
13:25 - Building AI products for 300 million users
15:20 - Why MiniMax plans to keep open-sourcing its models
17:29 - Agents that understand presentations and long videos
18:27 - Automating AI research with agent harnesses
19:27 - M3 is already helping build M3.1
19:55 - Why multi-agent systems come next