Card #825 · Cursor (AI IDE)
Proprietary Composer models fail when BYOK API keys are enabled
When a custom OpenAI or Anthropic API key is enabled, Cursor's proprietary Composer models (like Composer 2 and 2.5) return a 'Bad Request' error stating they do not support custom API keys. This forces users to manually toggle their API keys off and on when switching between standard models and Composer, severely disrupting the development workflow.
Pain score
0.71/ 1.00 · weighted product of four components
Reach0.72distinct authors (log-normalized)
Recency1.00freshness decay, half-life months
Engagement1.00upvotes + comments, normalized
Monetization0.50willingness-to-pay cues in evidence
§ Evidence — 5 verified quotes
When a custom OpenAI API Key is enabled in settings, selecting Composer 2 returns “Bad Request: This model does not support custom API keys.”
The IDE fails to route requests to explicitly selected Composer models (like Composer 2.5) if a Bring-Your-Own-Key (BYOK) OpenAI/Anthropic API key is enabled in the settings.
Manually toggling API keys on/off in the settings menu every time a developer switches between standard chat and Composer severely disrupts the development workflow.
When a custom OpenAI API key is enabled, it’s mistakenly applied to all models, including Composer, which should always go through Cursor servers.
Its current Bring Your Own Key (BYOK) feature is barely functional: users cannot configure any model parameters such as reasoning intensity and context window length
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