update docs

Author: icecrasher321

apps/docs/content/docs/en/execution/costs.mdx

@@ -104,6 +104,10 @@ The model breakdown shows:
   Pricing shown reflects rates as of September 10, 2025. Check provider documentation for current pricing.
 </Callout>
 
+## Bring Your Own Key (BYOK)
+
+You can use your own API keys for hosted models (OpenAI, Anthropic, Google, Mistral) in **Settings → BYOK** to pay base prices. Keys are encrypted and apply workspace-wide.
+
 ## Cost Optimization Strategies
 
 - **Model Selection**: Choose models based on task complexity. Simple tasks can use GPT-4.1-nano while complex reasoning might need o1 or Claude Opus.