OpenAI API key validation fails silently in Cursor IDE integration

What this error means

We encountered an issue when using your API key: Streaming error is a Cursor failure pattern reported for developers trying to fix api key rejected by cursor ide despite being valid elsewhere (works in other apps); need resolution for paid cursor subscription users.. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Verified via GitHub search results (kio-gateway issue #53, 2026-01-23) confirming Cursor IDE rejects valid API keys with ‘Streaming error’. Also supported by openai/codex #4092 showing similar auth issues with valid keys. Distinct from ‘OpenAI API key not working’ in covered-errors.md which refers to invalid keys. Category: Cursor (approved). Strong signal for paid Cursor users who have verified keys.

Common causes

• Verified via GitHub search results (kio-gateway issue #53, 2026-01-23) confirming Cursor IDE rejects valid API keys with ‘Streaming error’. Also supported by openai/codex #4092 showing similar auth issues with valid keys. Distinct from ‘OpenAI API key not working’ in covered-errors.md which refers to invalid keys. Category: Cursor (approved). Strong signal for paid Cursor users who have verified keys.

Quick fixes

1. Confirm the exact error signature matches We encountered an issue when using your API key: Streaming error.
2. Check the Cursor 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/jwadow/kiro-gateway/issues/53
• https://github.com/openai/codex/issues/4092

Evidence note: Verified via GitHub search results (kio-gateway issue #53, 2026-01-23) confirming Cursor IDE rejects valid API keys with ‘Streaming error’. Also supported by openai/codex #4092 showing similar auth issues with valid keys. Distinct from ‘OpenAI API key not working’ in covered-errors.md which refers to invalid keys. Category: Cursor (approved). Strong signal for paid Cursor users who have verified keys.

Related errors

• Cursor

FAQ

What should I check first?

Start with the exact We encountered an issue when using your API key: Streaming error text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Cursor 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 We encountered an issue when using your API key: Streaming error.