Update: After extensive investigation I have identified what appears to be the root cause of the 401 Invalid Bearer Token error on my Intel Mac, and I want to share the findings in case they help others reporting similar issues on M1 and M4 machines. WHAT I FOUND (Intel Mac - x86_64): The Claude Agent binary that Xcode downloads is the darwin-arm64 build regardless of host architecture. On my Intel Mac this binary physically cannot execute, which fails silently and surfaces as a 401 error. Confirmed via terminal: file ~/Library/Developer/Xcode/CodingAssistant/Agents/claude/2.1.14/claude Returns: Mach-O 64-bit executable arm64 — wrong for Intel Mac The IDEChatClaudeCodeVersion preference is hardcoded to the ARM64 download URL: defaults read com.apple.dt.Xcode IDEChatClaudeCodeVersion Returns: darwin-arm64 URL regardless of CPU architecture We also confirmed the darwin-x64 binary exists in Anthropic's distribution bucket and runs correctly on Intel — both in the terminal and as a standalone binary: curl -fsSL -o /tmp/claude-x64 "https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/2.1.14/darwin-x64/claude" /tmp/claude-x64 --version Returns: 2.1.14 (Claude Code) — works fine on Intel Claude Code also works perfectly in Terminal on this Intel Mac. The problem is exclusively with the Claude Agent inside Xcode, which downloads and attempts to run the wrong ARM64 binary. However, manually placing the x64 binary in the agent directory fails with: "Failed to initialize Claude Agent: The code signing identity for the agent did not match expectations, or the agent violated sandboxing rules." This means Xcode's code signing verification also rejects the x64 binary, so there is currently no workaround for Intel Mac users wanting to use the Claude Agent inside Xcode. Note: Claude chat in Xcode works perfectly on this Intel Mac — only the Agent and coding intelligence features are broken. This confirms the issue is the binary architecture, not account credentials, plan level, or network connectivity. Clearing all keychain entries, Xcode preferences, and cached credentials had no effect on the 401 error. A bug report has been filed with Anthropic here: https://github.com/anthropics/claude-code/issues/40642 IMPORTANT QUESTION FOR M1/M4 USERS: Since others on this thread are reporting the same 401 error on Apple Silicon machines where the ARM64 binary should work correctly, the architecture mismatch may not be the only cause of this error. Could affected M1/M4 users please run the following in Terminal and post the results: Check the binary architecture: file ~/Library/Developer/Xcode/CodingAssistant/Agents/claude/2.1.14/claude Check whether Claude chat works but agent features do not: Try the coding assistant chat vs inline code fixes and agentic coding features and report which work and which fail. Check your Claude plan: Pro, Max, Team, or Free This will help determine whether there are multiple separate bugs causing the same 401 error on different hardware, or one common root cause affecting everyone. If you are affected please also add a comment to the GitHub issue above with your Mac model and architecture so Anthropic can see the full scope of the problem.