--- title: Backends description: Backends on Vercel run on Fluid compute with Active CPU pricing, plus Instant Rollback, the Vercel Firewall, protected previews, and rolling releases. url: "https://vercel.com/kb/backends" published: 2025-11-03 last_updated: 2026-10-15 install_vercel_plugin: npx plugins add vercel/vercel-plugin --- # Backends Backends on Vercel run on Fluid compute with Active CPU pricing, plus Instant Rollback, the Vercel Firewall, protected previews, and rolling releases. ## Build with a Backend Template on Vercel - [Build with a Nitro starter template](/kb/guide/build-with-a-nitro-starter-template): Deploy a Nitro app to Vercel from a starter template. Compare the Nitro Starter, route rules, cached HTTP handler, plugins, Slack Bolt, and iMessage AI agent templates, then ship to a live URL. - [Build with a Hono starter template](/kb/guide/build-with-a-hono-starter-template): Deploy a Hono app to Vercel from a starter template. Compare the Hono API starter, MCP server, AI SDK, Slack Bolt, Next.js, Turborepo, and domco templates, then ship to a live URL. - [Build with an Express starter template](/kb/guide/build-with-a-express-starter-template): Deploy an Express app to Vercel from a template. Browse Express starters from Vercel and the community, then run them locally with the Vercel CLI. - [Build with a FastAPI starter template](/kb/guide/build-with-a-fastapi-starter-template): Browse FastAPI starter templates for Vercel and deploy one in a few steps. Compare minimal, AI, agent, and full-stack FastAPI templates on the Python runtime. - [Build with a Flask starter template](/kb/guide/build-with-a-flask-starter-template): Deploy a Flask app to Vercel from a starter template. Compare the Flask Hello World starter, AI SDK, alt text generator, and Next.js templates, then ship to a live URL. ## Migrate Your Python API - [Migrate a Python API from Heroku to Vercel](/kb/guide/migrate-a-python-api-from-heroku-to-vercel): Move a FastAPI, Flask, or Django API from Heroku to Vercel Functions. Replace your Procfile, worker dynos, Heroku Scheduler jobs, and Heroku Postgres. - [Migrate a Python API from Render to Vercel](/kb/guide/migrate-a-python-api-from-render-to-vercel): Move a FastAPI, Flask, or Django API from Render to Vercel Functions. Translate render.yaml and replace persistent disks, background workers, and cron jobs. - [Migrate a Python API from Railway to Vercel](/kb/guide/migrate-a-python-api-from-railway-to-vercel): Move a FastAPI, Flask, or Django API from Railway to Vercel Functions. Replace railway.json start commands, volumes, Celery workers, and cron services. ## Zero-Configuration Backends on Vercel - [Using xmcp with Next.js](/kb/guide/using-xmcp-with-nextjs): Add an MCP server to an existing Next.js app with xmcp. Create typed tools, add authentication, and deploy to Vercel as a Vercel Function. - [How to ship an H3 app on Vercel](/kb/guide/ship-a-h3-app-on-vercel): Deploy an H3 app to Vercel with zero configuration. Learn to configure streaming, middleware, cron jobs, the Bun runtime, and observability. - [How to ship a Fastify app on Vercel](/kb/guide/ship-a-fastify-app-on-vercel): Deploy a Fastify app to Vercel with zero configuration, then add streaming, lifecycle hooks, cron jobs, and observability. - [How to ship an Express app on Vercel](/kb/guide/ship-a-express-app-on-vercel): Deploy an Express app to Vercel with zero configuration. Configure response streaming, middleware, cron jobs, the Bun runtime, and observability. - [How to ship a FastAPI app on Vercel](/kb/guide/ship-a-fastapi-app-on-vercel): Deploy a FastAPI app to Vercel with zero configuration. Learn how the Python runtime, Vercel Functions, streaming, middleware, and cron jobs work together. - [How to ship a Koa app on Vercel](/kb/guide/ship-a-koa-app-on-vercel): Deploy a Koa app to Vercel with zero configuration. Learn how to ship from the Vercel CLI or Git, and configure response streaming, middleware, cron jobs, and Observability. - [How to ship a NestJS app on Vercel](/kb/guide/ship-a-nestjs-app-on-vercel): Deploy a NestJS app to Vercel with zero configuration. Learn how to ship from a template, the Nest CLI, or Git, and configure response streaming, middleware, cron jobs, and Observability. - [How to ship a Flask app on Vercel](/kb/guide/ship-a-flask-app-on-vercel): Deploy a Flask app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure response streaming, middleware, cron jobs, the Bun runtime, and Observability. - [How to ship an Elysia app on Vercel](/kb/guide/ship-a-elysia-app-on-vercel): Deploy a Elysia app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure response streaming, middleware, cron jobs, the Bun runtime, and Observability. - [How to ship a Nitro app on Vercel](/kb/guide/ship-a-nitro-app-on-vercel): Deploy a Nitro app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure ISR, cron jobs, Vercel Queues, per-route function settings, and Observability. - [How to ship a Hono app on Vercel](/kb/guide/ship-a-hono-app-on-vercel): Deploy a Hono app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure response streaming, middleware, cron jobs, the Bun runtime, and Observability. ## Learn more about Python - [7 practical use cases for a Python backend in a Next.js app](https://vercel.com/i/python-backend-nextjs-use-cases): See when a Python backend adds value to a Next.js app, with examples for AI, data analysis, document processing, predictions, and existing applications. - [How to connect a Python AI agent to a Next.js app](https://vercel.com/i/python-ai-agent-nextjs): Connect a Python AI agent to Next.js with FastAPI and AI SDK UI. Stream responses, display Python tool results, and configure a shared deployment. - [Where should you host a Python API?](https://vercel.com/i/where-to-host-python-api): Choose Python API hosting by framework support, dependencies, execution limits, storage, and where your frontend and database run. ## All Backends guides - [Store and serve files from Python with Vercel Blob](/kb/guide/python-and-vercel-blob): Upload, list, stream, and protect files from a Python app with Vercel Blob, including private per-user storage in FastAPI. - [Process background jobs in Python with Vercel Queues](/kb/guide/python-and-vercel-queues): Move slow and failure-prone work out of your Python request handlers, with typed topics, consumer groups, and built-in retries. - [Run untrusted Python code safely with Vercel Sandbox](/kb/guide/python-and-vercel-sandbox): Execute untrusted and AI-generated code from Python in isolated microVMs, with files, processes, network policies, and snapshots. - [Migrate Railway workers to Vercel Daemons](/kb/guide/migrate-railway-workers-to-vercel-daemons): Move Railway workers to Vercel Daemons with Docker configuration, broker migration, shutdown testing, a gradual queue handoff, and rollback. - [Call third-party APIs from Python with Vercel Connect](/kb/guide/python-and-vercel-connect): Call Slack and Linear APIs from Python with Vercel Connect. Request app and user tokens, handle consent, and verify provider events in FastAPI. - [Build durable workflows in Python on Vercel](/kb/guide/python-and-durable-workflows): Keep long-running Python jobs alive through crashes and deploys with steps, retries, sleeps, and hooks. - [Migrate Render background workers to Vercel Daemons](/kb/guide/migrate-render-workers-to-vercel-daemons): Migrate Render workers to Vercel Daemons. Translate render.yaml, package Celery in Docker, prepare the broker, and verify the queue handoff. - [Build AI agents in Python with the AI SDK](/kb/guide/python-and-ai-sdk): Stream model responses, get typed output, and build tool-using agents in Python on Vercel. - [Migrate Fly.io worker processes to Vercel Daemons](/kb/guide/migrate-fly-io-workers-to-vercel-daemons): Migrate Fly.io workers to Vercel Daemons with your existing Dockerfile. Map process settings, preserve queue state, and plan cutover and rollback. - [How to choose between Functions, containers, and Daemons on Vercel](/kb/guide/vercel-functions-containers-daemons): Choose Vercel Functions for HTTP requests, container images for custom runtimes, and Daemons for continuous background workers. - [Migrate a Python API from Railway to Vercel](/kb/guide/migrate-a-python-api-from-railway-to-vercel): Move a FastAPI, Flask, or Django API from Railway to Vercel Functions. Replace railway.json start commands, volumes, Celery workers, and cron services. - [Migrate a Python API from Render to Vercel](/kb/guide/migrate-a-python-api-from-render-to-vercel): Move a FastAPI, Flask, or Django API from Render to Vercel Functions. Translate render.yaml and replace persistent disks, background workers, and cron jobs. - [Use Vercel Passport with Node.js and Python backends](/kb/guide/vercel-passport-backend-frameworks): Secure internal apps and verify a visitor's identity with Vercel Passport in your backend, with examples for Express, Hono, Nitro, and FastAPI. - [Migrate a Python API from Heroku to Vercel](/kb/guide/migrate-a-python-api-from-heroku-to-vercel): Move a FastAPI, Flask, or Django API from Heroku to Vercel Functions. Replace your Procfile, worker dynos, Heroku Scheduler jobs, and Heroku Postgres. - [Does Vercel support Docker deployments?](/kb/guide/does-vercel-support-docker-deployments): Vercel supports deploying OCI-compatible container images through Vercel Functions and Vercel Container Registry, with Active CPU pricing and automatic scaling. - [Running Docker on Vercel vs Render](/kb/guide/docker-on-vercel-vs-render): Compare how Vercel and Render run Docker workloads, including deployment model, scaling, image sources, state, and networking. - [How to use Vercel Container Registry](/kb/guide/how-to-use-vercel-container-registry): Push, store, and pull OCI container images with Vercel Container Registry, then deploy them to Vercel Functions and Vercel Sandbox. - [Running Docker on Vercel](/kb/guide/docker): Run Docker on Vercel for HTTP apps and background workers, store images in Vercel Container Registry, and test containers with Vercel Sandbox. - [The Complete Guide to Vercel Services](/kb/guide/vercel-services): Vercel Services let you deploy multiple frontends and backends in one project on a shared domain. Learn how to define services in vercel.json, route requests by path prefix, and connect services with generated environment variables. - [How Vercel Services run on Fluid compute](/kb/guide/vercel-services-fluid-compute): The backends in a Vercel Services project run as Vercel Functions on Fluid compute by default. Learn how optimized concurrency, Active CPU pricing, and per-service memory and maxDuration settings make multi-backend projects efficient. - [Choosing how to structure your application on Vercel](/kb/guide/structure-your-application): Compare three ways to structure an application on Vercel (a single framework, one project with Services, or separate projects in a monorepo) and learn how to choose based on domains, deploy coupling, and languages. - [Build Figma-style multiplayer cursors with WebSockets on Vercel](/kb/guide/real-time-board-nextjs-fastapi): Learn how to build Figma-style multiplayer cursors with Next.js and FastAPI, kept consistent across multiple Vercel Function instances using WebSockets and Redis. - [Build a real-time chat app with WebSockets on Vercel](/kb/guide/real-time-chat-websockets): Build and deploy a single-room messaging app in Next.js with real-time chat, typing indicators, and live online user counts using WebSockets and Redis. - [How to ship a NestJS app on Vercel](/kb/guide/ship-a-nestjs-app-on-vercel): Deploy a NestJS app to Vercel with zero configuration. Learn how to ship from a template, the Nest CLI, or Git, and configure response streaming, middleware, cron jobs, and Observability. - [Build with an Express starter template](/kb/guide/build-with-a-express-starter-template): Deploy an Express app to Vercel from a template. Browse Express starters from Vercel and the community, then run them locally with the Vercel CLI. - [How to ship a Fastify app on Vercel](/kb/guide/ship-a-fastify-app-on-vercel): Deploy a Fastify app to Vercel with zero configuration, then add streaming, lifecycle hooks, cron jobs, and observability. - [How to ship an Express app on Vercel](/kb/guide/ship-a-express-app-on-vercel): Deploy an Express app to Vercel with zero configuration. Configure response streaming, middleware, cron jobs, the Bun runtime, and observability. - [How to ship a Koa app on Vercel](/kb/guide/ship-a-koa-app-on-vercel): Deploy a Koa app to Vercel with zero configuration. Learn how to ship from the Vercel CLI or Git, and configure response streaming, middleware, cron jobs, and Observability. - [How to ship an H3 app on Vercel](/kb/guide/ship-a-h3-app-on-vercel): Deploy an H3 app to Vercel with zero configuration. Learn to configure streaming, middleware, cron jobs, the Bun runtime, and observability. - [Build with a FastAPI starter template](/kb/guide/build-with-a-fastapi-starter-template): Browse FastAPI starter templates for Vercel and deploy one in a few steps. Compare minimal, AI, agent, and full-stack FastAPI templates on the Python runtime. - [How to ship a FastAPI app on Vercel](/kb/guide/ship-a-fastapi-app-on-vercel): Deploy a FastAPI app to Vercel with zero configuration. Learn how the Python runtime, Vercel Functions, streaming, middleware, and cron jobs work together. - [Build with a Flask starter template](/kb/guide/build-with-a-flask-starter-template): Deploy a Flask app to Vercel from a starter template. Compare the Flask Hello World starter, AI SDK, alt text generator, and Next.js templates, then ship to a live URL. - [Using xmcp with Next.js](/kb/guide/using-xmcp-with-nextjs): Add an MCP server to an existing Next.js app with xmcp. Create typed tools, add authentication, and deploy to Vercel as a Vercel Function. - [How to ship a Flask app on Vercel](/kb/guide/ship-a-flask-app-on-vercel): Deploy a Flask app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure response streaming, middleware, cron jobs, the Bun runtime, and Observability. - [How to ship an Elysia app on Vercel](/kb/guide/ship-a-elysia-app-on-vercel): Deploy a Elysia app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure response streaming, middleware, cron jobs, the Bun runtime, and Observability. - [Build with a Nitro starter template](/kb/guide/build-with-a-nitro-starter-template): Deploy a Nitro app to Vercel from a starter template. Compare the Nitro Starter, route rules, cached HTTP handler, plugins, Slack Bolt, and iMessage AI agent templates, then ship to a live URL. - [How to ship a Hono app on Vercel](/kb/guide/ship-a-hono-app-on-vercel): Deploy a Hono app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure response streaming, middleware, cron jobs, the Bun runtime, and Observability. - [How to ship a Nitro app on Vercel](/kb/guide/ship-a-nitro-app-on-vercel): Deploy a Nitro app to Vercel with zero configuration. Learn how to ship from a template, the Vercel CLI, or Git, and configure ISR, cron jobs, Vercel Queues, per-route function settings, and Observability. - [Build with a Hono starter template](/kb/guide/build-with-a-hono-starter-template): Deploy a Hono app to Vercel from a starter template. Compare the Hono API starter, MCP server, AI SDK, Slack Bolt, Next.js, Turborepo, and domco templates, then ship to a live URL. - [What is the Nitro Vite plugin?](/kb/guide/nitro-vite-plugin): The Nitro Vite plugin (nitro/vite) adds SSR, API routes, and deploy-anywhere server builds to any Vite app. Learn what it does and how it runs on Vercel. - [Build a fullstack app with Next.js 16 and Prisma Postgres](/kb/guide/nextjs-prisma-postgres): Create a fullstack blog with the Next.js App Router, Prisma, Sign in with Vercel, Prisma Postgres from the Vercel Marketplace, and deploy it to Vercel. - [How to create a contentful asset on Vercel](/kb/guide/how-to-create-a-contentful-asset-on-vercel): This is my wonderful - [How to gradually roll out new versions of your backend](/kb/guide/how-to-gradually-roll-out-new-versions-of-your-backend): Incrementally release updates to your backend to minimize impact of mistakes. - [Efficiently manage database connection pools with Fluid compute](/kb/guide/efficiently-manage-database-connection-pools-with-fluid-compute): How to create high-performance database connection pools without leaking connections - [Using Vercel Sandbox to run Claude’s Agent SDK](/kb/guide/using-vercel-sandbox-claude-agent-sdk): Learn how to deploy Claude's Agent SDK in Vercel Sandbox for secure and isolated execution of AI-powered code generation and autonomous agent tasks. - [Build an MCP Server with Weather tools using Express and Vercel](/kb/guide/mcp-server-with-weather-tool-express): Make your Express weather API accessible to AI assistants through the Model Context Protocol. - [Build an AI Chat Agent with Weather API Tool Calling](/kb/guide/build-ai-agent-weather-api): Build an intelligent conversational agent that fetches real-time weather data using the AI SDK, tool calling, and a backend weather API powered by Express, FastAPI or Nitro - [Build a Weather API on Vercel: Express, FastAPI, and Nitro](/kb/guide/weather-api-with-fastapi): Build a weather API on Vercel with FastAPI, Express, or Nitro. Compare the three runtimes, add caching and Observability, then deploy the route. - [How to enable CORS on Vercel](/kb/guide/how-to-enable-cors): Learn how to enable CORS on Vercel with vercel.json, Routing Middleware, framework config, and route handlers, plus how to fix preflight blocked by Deployment Protection. - [Hosting your API on Vercel](/kb/guide/hosting-backend-apis): Learn how to build and scale performant APIs on Vercel. - [Troubleshooting Vercel Cron Jobs](/kb/guide/troubleshooting-vercel-cron-jobs): Learn how to troubleshoot cron jobs that aren't being run or logged when using Vercel Cron Jobs. - [How can I use geolocation IP headers?](/kb/guide/geo-ip-headers-geolocation-vercel-functions): Learn how to read geolocation headers on Vercel with Next.js or any frontend framework. ## Explore other topics in the Vercel Knowledge Base - [Docker](/kb/docker): Deploy HTTP applications from a standard Dockerfile with Vercel Functions, and run continuous background workers with Vercel Daemons. Find deployment and migration guides for both. - [Migrations](/kb/migrations): Learn how to migrate your application or agent to Vercel's agentic infrastructure. - [Vercel Sandbox](/kb/vercel-sandbox): The compute primitive designed to safely run untrusted or user-generated code on Vercel. - [Infrastructure and Compute](/kb/infrastructure-and-compute): Scale and deliver applications efficiently across regions using Vercel's Fluid Compute and CDN.