> ## Documentation Index > Fetch the complete documentation index at: https://partners.usecharlie.ai/llms.txt > Use this file to discover all available pages before exploring further. # Custom development. > Where partner involvement may be needed — and where to find the relevant documentation. Most of Charlie's setup requires zero development. There is 1 area where partner involvement may be needed: **safety stock in Block mode**. ## Why Block mode matters. Charlie's safety stock has 2 modes. In **Block mode**, sellable inventory is enforced globally — meaning every tool that reads Shopify's native stock data will be affected. This includes storefronts, POS extensions, back-in-stock apps, and any third-party tool connected to Shopify inventory. When a client activates Block mode, it's important to audit which tools in their stack read native inventory — and ensure each one handles sellable stock correctly. ## Integrations. Charlie is actively building native integrations for the most common tools. **Depict** is currently in progress. For other tools, the level of effort depends on the tool itself: * Some work out of the box * Some require configuration * Some require development work on the partner's side Charlie maintains documentation for the most common integration scenarios. For tools like **Klaviyo** (back-in-stock notifications), implementation guides are available in the product docs. Implementation guides for specific tools and scenarios. Charlie's brand guidelines and materials for client-facing use.