Update — Anthropic Just Introduced a Massive Workflow Breakage

Anthropic has just fully enforced a change that blocks OAuth-based API keys from being used with third-party tools. Practically speaking, this means Opencode no longer works with your Claude Max or Pro subscription. The integration that made everything feel seamless and “unlimited” is gone. Cold turkey again.

Users that want to stay with opencode get pushed back into usage-based API billing, which completely changes the economics. The whole point of using Opencode with a Claude subscription was that you could rely on predictable, flat-rate access while benefiting from a flexible, open-source agent with deeply integrated workflow. Losing that forces you back into carefully watching tokens and billable requests or Claude Code.

And I have to say it plainly: this feels like a big, big fumble on Anthropic’s part. Third-party tooling was rapidly becoming one of the strongest reasons to stick with Claude for me. Tools like Opencode increased the value of the subscription enormously. Cutting off OAuth keys limits that ecosystem overnight and sends a pretty confusing signal about the direction Anthropic wants developers to take.

Instead of encouraging innovation around their platform, the move effectively discourages experimentation and funnels users into the most expensive and locked-in path. That’s not just inconvenient, it’s strategically short-sighted. Healthy ecosystems grow outward, not inward.

So, until this gets sorted out (if it ever does), I’m reverting back to Claude Code. It’s not quite the same magic as the opencode integration, but I can rely on it day-to-day without constantly checking token usage. If Opus wasn't so damn good but expensive I would have left Claude Code for API-based usage.