Developers using OpenCode, an open-source terminal-based AI coding assistant, are reporting that Anthropic has started returning 429 (Too Many Requests) errors to the tool's user agent. The block appears to affect all OpenCode users attempting to connect to Claude's API.
OpenCode is one of several open-source alternatives to commercial AI coding tools like Claude Code and Cursor. It lets developers interact with language models directly from their terminal. The 429 responses suggest Anthropic is specifically identifying and rejecting requests coming from OpenCode's client, rather than applying a general rate limit.
This isn't the first time an AI provider has restricted third-party clients. API providers regularly enforce usage policies through user-agent filtering, especially when third-party tools route requests in ways that don't align with their terms of service or pricing tiers. For developers who rely on OpenCode as their daily coding workflow, the immediate fix is likely switching to Anthropic's official tools or using the API directly with a standard client.
No official statement from Anthropic on the block so far.