Blog post published on Zed's blog on May 14, 2026 by Franciska Dethlefsen (head of growth and marketing), the day after an Anthropic announcement and in response to user questions — "the details have been hard to parse".

What's changing. Starting June 15, Anthropic splits Claude subscription billing into two pools: first-party tools (chat, official Claude Code CLI) on one side, third-party agent and SDK usage on the other — anything going through ACP, claude -p, or a third-party application. This usage stops drawing from Pro or Max limits and switches to a monthly Agent SDK credit: $20 (Pro), $100 (Max 5x), $200 (Max 20x). Once the credit is exhausted, usage continues at standard API pricing if overage is enabled; otherwise requests stop until the next cycle.

Why it's significant. Subscriptions subsidized agentic usage by roughly 15 to 30× relative to API pricing, and the new credits are billed at full API pricing. Hence the verdict: "for anyone using agents heavily, this is a major cost increase".

The three options. First, stay on the subscription by launching the official claude CLI in a terminal inside Zed rather than via ACP — the same tool then retains subscription limits. Next, Zed's built-in agent with the provider of one's choice: Zed-hosted models, API keys, Copilot, local Ollama, DeepSeek. Finally, any ACP agent — OpenCode, Codex, Factory, Cursor — several of which still offer rate-limited subscriptions that subsidize heavy usage. Along the way, the post slips in the announcement of Terminal Threads, meant to make TUI agents a first-class element of orchestration in Zed.

The thesis. "ACP is an open protocol… so that your editor is never locked into one provider's pricing decisions." With an explicit anticipation: "We suspect this kind of change won't be the last." The open-protocol argument here is not technical but economic — it protects less against incompatibility than against a pricing decision.

Addendum of June 16, 2026. Anthropic suspends the change: ACP, claude -p, the Agent SDK, and third-party applications continue to work with subscriptions exactly as before, no separate credit exists, limits are unchanged. The post therefore describes a pricing regime that never took effect — and its most important piece of information postdates its own publication by a month.