Fable came and went in a week. Shane and Abhi break down the strangest model launch yet — Claude Fable 5, a Mythos-class model Anthropic said was too capable to release widely, until a US export-control directive made it vanish for everyone.

We cover the whole arc: the launch hype, the pricing that had people spending $1,000 a day, the silent fallbacks to Opus, the system-prompt leak, and the snitch that triggered a 90-minute shutdown. Then a stacked back half — China's open-weight surge, OpenRouter Fusion, loop engineering vs loopcraft, the agent-learning gold rush, OpenAI filing to go public, and Dario's new essay.

AI Agents Hour is a weekly livestream by Mastra CPO Shane Thomas and CTO Abhi Aiyer. Mondays 12PM Pacific.

📚 READ MORE
Claude Fable 5 launch: https://x.com/claudeai/status/2064394146916229443
Pokémon beaten with vision: https://x.com/Baconbrix/status/2064418858073784530
Export-control announcement: https://x.com/anthropicai/status/2065597531644743999
Amazon/WSJ report (Theo): https://x.com/theo/status/2065665304882209132
David Sacks on the ban: https://x.com/davidsacks/status/2065853007619588171
Token capital (Satya Nadella): https://x.com/satyanadella/status/2066182223213293753
Siri as a harness (Weinbach): https://x.com/mweinbach/status/2065630219021492474
MiniMax M3 open weights: https://x.com/minimax_ai/status/2065436935188058208
GLM 5.2: https://x.com/zai_org/status/2065704919299235870
Kimi K2 Code High Speed: https://x.com/kimi_moonshot/status/2066467110960959833
Cohere North Mini Code: https://x.com/cohere/status/2064378058329526556
Gemma 4 on consumer hardware: https://x.com/unslothai/status/2065433326706684135
Diffusion Gemma: https://x.com/unslothai/status/2065107734916432189
OpenRouter Fusion API: https://x.com/openrouter/status/2065856853989270011
AI SDK harnesses (Vercel): https://x.com/vercel_dev/status/2065509970775519569
Swyx on loopcraft: https://x.com/swyx/status/2065307558198567206
OpenEnv joins Hugging Face: https://x.com/ben_burtenshaw/status/2063991191415267492
Adaline 2.0 / agent learning: https://x.com/adiix_official/status/2066172819952566643
Cognition Frontier Code: https://x.com/cognition/status/2064061031912288715
Ramp SWE-bench: https://x.com/RampLabs/status/2065485806605619304
AWS on AI-generated code: https://x.com/awscloud/status/2064449711155589396
OpenAI files to go public: https://x.com/OpenAINewsroom/status/2065088002335158753
OpenAI acquires Ona: https://x.com/OpenAINewsroom/status/2064094175541461220
Salesforce acquires Fin AI: https://x.com/fin_ai/status/2066493998852686074
Mistral in talks to raise: https://x.com/business/status/2065420995393941692
Dario's essay on the AI exponential: https://x.com/DarioAmodei/status/2064781775247950326

📚 MASTRA RESOURCES
Mastra: https://mastra.ai
Mastra on X: https://x.com/mastra_ai
Mastra Discord: https://mastra.ai/community/discord
Mastra GitHub: https://github.com/mastra-ai
Learn Mastra in the world's first MCP-Based Course: https://mastra.ai/course
Principles of Building AI Agents (Book): https://mastra.ai/books/principles-of-building-ai-agents
Patterns for Building AI Agents (New Book): https://mastra.ai/books/patterns-of-building-ai-agents

WHAT IS MASTRA?
Mastra is an open-source TypeScript framework designed for building and shipping AI-powered applications and agents with minimal friction. It supports the full lifecycle of agent development—from prototype to production. You can integrate it with frontend and backend stacks (e.g., React, Next.js, Node) or run agents as standalone services. If you're a JavaScript or TypeScript developer looking to build an agentic or AI-powered product without starting from first principles, Mastra provides the scaffolding, tools, and integrations to accelerate that process.

⏱️ CHAPTERS
00:00 Cold open & welcome
00:40 Claude Fable 5: the launch and the hype
01:53 The price problem and silent Opus fallbacks
06:42 Our experience + the system-prompt leak
08:51 The 90-minute export-control shutdown
12:40 Microsoft's "token capital" & where Fable goes
17:07 Apple at WWDC: Siri as a harness
17:57 China's open models: MiniMax M3, GLM 5.2, Kimi K2
21:11 Local-first: Cohere, AMD, Diffusion Gemma
24:58 OpenRouter Fusion & AI SDK harnesses
27:07 Loop engineering, loopcraft & OpenEnv
29:09 Agent learning & new coding benchmarks
32:14 AWS, the snitch & OpenAI's IPO
33:37 Salesforce, Mistral & Le Chaton Fat
36:42 Quick hits & a Fable eulogy