January 9, 2026. No warning. Anthropic blocked third-party tools from using Claude subscription tokens via OAuth. Developers were mid-session when access died.
The target: “harnesses.” OpenCode. OpenClaw. Anything that wasn’t Anthropic’s own client.
This is Sherlocking. Apple perfected it. Let third-party developers build what you didn’t bother to. Watch what gets popular. Build your own version. Kill theirs.
Anthropic shipped Claude Code. OpenCode offered the same thing but better. IDE integration, shortcuts, team features. So Anthropic blocked it.
OpenCode shipped an OpenAI integration within hours. Developers paying $200/month started canceling. Not because Claude got worse. Because the workflow they’d built got killed overnight.
The developers who use third-party tools are the same developers who tweet about Claude, recommend it, build on it. They’re not customers. They’re distribution.
Every platform starts open. Then the ecosystem matures, and the developers who built that value become competition.
The model is commodity. The wrapper is the moat.