Claude Code Hanging Freezing on Opus 4.6 — SSE Events Not Flowing

What this error means

Claude Code hangs freezing — stuck on thinking for 5-20 minutes with no token usage is a Claude Code failure pattern reported for developers trying to fix claude code hanging/freezing for 5-20+ minutes during prompts with opus 4.6 model. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Open GitHub issue with 100 comments. Regression since Opus 4.6 release. Verified via packet inspection that SSE events stop from Anthropic’s end. Not a local issue — fresh install with no MCPs/skills reproduces. Affects multiple platforms.

Common causes

• Claude Code with Opus 4.6 model frequently hangs during prompts — token usage stays flat, SSE events stop flowing from Anthropic’s end. Packet inspection confirms it’s waiting on Anthropic’s side, not local processing. Sometimes unfreezes after 5-20 minutes, sometimes requires follow-up prompts. Affects WSL2/Linux/macOS users.
• Open GitHub issue with 100 comments. Regression since Opus 4.6 release. Verified via packet inspection that SSE events stop from Anthropic’s end. Not a local issue — fresh install with no MCPs/skills reproduces. Affects multiple platforms.

Quick fixes

1. Confirm the exact error signature matches Claude Code hangs freezing — stuck on thinking for 5-20 minutes with no token usage.
2. Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/anthropics/claude-code/issues/26224

Evidence note: Open GitHub issue with 100 comments. Regression since Opus 4.6 release. Verified via packet inspection that SSE events stop from Anthropic’s end. Not a local issue — fresh install with no MCPs/skills reproduces. Affects multiple platforms.

Related errors

• Claude Code no response from API
• Claude Code SSE stream stopped
• Claude Opus model hanging issue

FAQ

What should I check first?

Start with the exact Claude Code hangs freezing — stuck on thinking for 5-20 minutes with no token usage text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Claude Code workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without Claude Code hangs freezing — stuck on thinking for 5-20 minutes with no token usage.