OpenAI API Key Authentication Fails when OpenRouter as provider

What version of Codex is running?

0.1.2505172129

Which model were you using?

_No response_

What platform is your computer?

_No response_

What steps can reproduce the bug?

export OPENAI_API_KEY="your-actual-openai-api-key"
export OPENROUTER_API_KEY="your-openrouter-api-key"
codex -q --provider openrouter --model openai/gpt-4.1 "hello"

What is the expected behavior?

But when we set:

export OPENAI_API_KEY="your-openrouter-api-key"  # Why this should be Openrouter Key
export OPENROUTER_API_KEY="your-openrouter-api-key"
codex -q --provider openrouter --model openai/gpt-4.1 "hello"

It runs smoothly

What do you see instead?

_No response_

Additional information

_No response_