GitHub Copilot HTTP 200 Response Does Not Appear to Originate from GitHub Authentication Error

What this error means

ProxiedResponseError [FetchResponseError]: HTTP 200 response does not appear to originate from GitHub. Is a proxy or firewall intercepting this request? is a GitHub Copilot failure pattern reported for developers trying to fix github copilot authentication failure with http 200 response origin error on macos. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issues github/copilot.vim#282 and #283 (May 8-10, 2026): Copilot language server throws ProxiedResponseError during auth/embedding type fetch even without proxy configured. Related to npx upgrade (11.12.1) and response content-type validation. Affects Neovim + copilot.vim and Zed on macOS. Category: GitHub Copilot (subscription auth failure).

Common causes

• GitHub issues github/copilot.vim#282 and #283 (May 8-10, 2026): Copilot language server throws ProxiedResponseError during auth/embedding type fetch even without proxy configured. Related to npx upgrade (11.12.1) and response content-type validation. Affects Neovim + copilot.vim and Zed on macOS. Category: GitHub Copilot (subscription auth failure).

Quick fixes

1. Confirm the exact error signature matches ProxiedResponseError [FetchResponseError]: HTTP 200 response does not appear to originate from GitHub. Is a proxy or firewall intercepting this request?.
2. Check the GitHub Copilot account, local tool state, and provider configuration involved in the failing workflow.
3. Verify the account session, API key, provider settings, and environment where the failing tool is running.

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/github/copilot.vim/issues/282
• https://github.com/github/copilot.vim/issues/283

Evidence note: GitHub issues github/copilot.vim#282 and #283 (May 8-10, 2026): Copilot language server throws ProxiedResponseError during auth/embedding type fetch even without proxy configured. Related to npx upgrade (11.12.1) and response content-type validation. Affects Neovim + copilot.vim and Zed on macOS. Category: GitHub Copilot (subscription auth failure).

Related errors

• GitHub Copilot

FAQ

What should I check first?

Start with the exact ProxiedResponseError [FetchResponseError]: HTTP 200 response does not appear to originate from GitHub. Is a proxy or firewall intercepting this request? text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed GitHub Copilot 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 ProxiedResponseError [FetchResponseError]: HTTP 200 response does not appear to originate from GitHub. Is a proxy or firewall intercepting this request?.