xAI

Why has GRPO eaten PPO's lunch in 2025-2026 reasoning post-training?

Walk through SWE-bench, AgentBench, GAIA, and TAU-bench: what they measure, their shared blind spots, and how to interpret agent benchmark numbers.

Flashcard: what is the ReAct prompting pattern?

Flashcard: what is a token in LLM prompting and why does it matter for cost and context?

You have 500KB of relevant documentation that exceeds the 200K-token context window of your production model. How should you choose between context stuffing (fit what you can) and RAG retrieval?

Three concrete situations where fine-tuning is the wrong tool

Which of these are valid reasons NOT to fine-tune?

Match each multi-agent framework to its coordination model

How do you define a cost per task budget for an agent and enforce it at runtime?

Why does token cost grow super-linearly with agent step count, and what architectural decisions reduce it?