Anthropic blocks third-party use of Claude Code subscriptions

Original Article ↗ Hacker News Discussion ↗

What Anthropic Changed

  • Anthropic restricted Claude Code subscription credentials so they can only be used by official Claude Code clients, not by third‑party CLIs like OpenCode or Crush that were spoofing the client.
  • Regular pay‑per‑token API keys still work fine in OpenCode and others; only the “Claude/Max via Claude Code” subscription path is blocked.
  • Some third‑party clients using Claude Code via ACP or the official Agent SDK appear unaffected, since they’re treated as first‑party surfaces.

Loophole vs. Terms of Service

  • Many commenters note this use was always a ToS violation and depended on reverse‑engineering and “you are Claude Code” prompts; they see this as Anthropic finally closing an obvious loophole.
  • Others argue that from a user’s perspective, they were paying for model access, not a specific UI, so losing third‑party usage feels like a paid feature being removed, even if it was never officially supported.

Economics, Lock‑In, and Data

  • Strong consensus that Claude Code/Max is heavily subsidized: for power users, equivalent API usage would reportedly cost multiples of the $200/month fee.
  • One camp says it’s rational for Anthropic to constrain how that loss‑leader is used, to avoid third parties extracting maximum tokens without giving Anthropic product lock‑in, telemetry, or training data.
  • Another camp frames this as early “enshittification” and vendor lock‑in: using pricing to force a buggy first‑party tool instead of letting the best harness win.

Technical Details and Arms Race

  • Under the hood, Anthropic initially gated access via mild behavioral checks (system prompt, tool names like read), which OpenCode and others mimicked; Anthropic then blocked those patterns.
  • Workarounds landed quickly (renaming tools, updated auth plugins), but several predict a cat‑and‑mouse escalation: obfuscation, cert pinning, behavior analysis, and possibly “BotGuard‑style” client integrity systems.

Claude Code vs. OpenCode Quality

  • Many developers praise OpenCode’s engineering (TUI runtime, web/desktop reuse, multi‑provider support, fewer UI bugs) and call Claude Code flickery, sluggish, and janky in tmux/screen.
  • Others report Claude Code works fine for them and note its careful token optimization, tool selection, and tight integration with Anthropic’s models.

User Reactions and Switching

  • Visible number of users say they canceled Claude subscriptions or won’t renew, moving to OpenAI, GLM, Grok, Cerebras, or other coding agents via OpenCode.
  • Some shrug, seeing this as an inevitable tightening of “unlimited” SOTA offerings and a reminder that models are becoming a commodity while control over the client/harness becomes the real battleground.