# Zapier Functions > Serverless TypeScript/JavaScript inside Zapier—build custom logic and mini-apps that plug into 8,000+ integrations, Zaps, and Interfaces. Zapier Functions lets you write and run TypeScript or JavaScript without managing servers, then wire that logic into Zaps, Interfaces, and 8,000+ app integrations. Author code in a built-in editor with instant deploys and versioned edits, call external APIs, enrich data, and return structured outputs for the next Zap step. Use Functions to blend low-code and code: keep Zaps readable while handling tricky transformations, validations, and business rules in TS/JS. ## Features - Serverless TypeScript/JavaScript runtime in Zapier - Integrates with Zaps and Interfaces - Use with 8,000+ app connections - Built-in auth handled by Zapier - Data transforms and API calls - Instant deploys and versioned edits ## Integrations Webhooks by Zapier, Google Sheets, Slack, Gmail, HubSpot ## Platforms WEB, API ## Pricing Subscription-based ## Links - Website: https://zapier.com/functions - Documentation: https://www.youtube.com/watch?v=2tCDQz5A-JQ - EveryDev.ai: https://www.everydev.ai/tools/zapier-functions