Presets

Presets

Presets are reusable configuration packages that integrate React Router with deployment platforms, tools, and frameworks.

Overview

A preset is a package that provides:

• Default React Router configuration
• Platform-specific optimizations
• Custom build hooks
• Deployment integrations

Using Presets

Add presets to your react-router.config.ts:

import { cloudflarePreset } from "@react-router/cloudflare";

export default {
  presets: [cloudflarePreset()],
} satisfies Config;

Available Presets

Cloudflare

Deploy to Cloudflare Pages or Workers:

npm install @react-router/cloudflare

import { cloudflarePreset } from "@react-router/cloudflare";

export default {
  presets: [cloudflarePreset()],
} satisfies Config;

Vercel

Deploy to Vercel:

npm install @react-router/vercel

import { vercelPreset } from "@react-router/vercel";

export default {
  presets: [vercelPreset()],
} satisfies Config;

Netlify

Deploy to Netlify:

npm install @react-router/netlify

import { netlifyPreset } from "@react-router/netlify";

export default {
  presets: [netlifyPreset()],
} satisfies Config;

Creating Custom Presets

Create your own preset for custom integrations:

import type { Preset } from "@react-router/dev/config";

export function myPreset(): Preset {
  return {
    name: "my-preset",
    
    async reactRouterConfig({ reactRouterUserConfig }) {
      // Return config overrides
      return {
        serverModuleFormat: "esm",
        buildDirectory: "dist",
        
        async buildEnd({ buildManifest, reactRouterConfig, viteConfig }) {
          // Run after build completes
          console.log("Build finished!");
          
          // Deploy, generate files, etc.
          await deployToMyPlatform(buildManifest);
        },
      };
    },
    
    async reactRouterConfigResolved({ reactRouterConfig }) {
      // Called after all config is resolved
      console.log("Config resolved:", reactRouterConfig);
    },
  };
}

Preset API

name

A unique identifier for your preset:

export function myPreset(): Preset {
  return {
    name: "my-preset",
  };
}

reactRouterConfig()

Provide default configuration:

export function myPreset(): Preset {
  return {
    name: "my-preset",
    
    reactRouterConfig({ reactRouterUserConfig }) {
      return {
        // Set defaults
        serverModuleFormat: "esm",
        ssr: true,
        
        // Conditional config based on user config
        buildDirectory: reactRouterUserConfig.buildDirectory || "build",
        
        // Build hooks
        async buildEnd({ buildManifest }) {
          // Post-build logic
        },
      };
    },
  };
}

reactRouterConfigResolved()

Run code after config is fully resolved:

export function myPreset(): Preset {
  return {
    name: "my-preset",
    
    async reactRouterConfigResolved({ reactRouterConfig }) {
      // Validate config
      if (reactRouterConfig.ssr === false) {
        throw new Error("This preset requires SSR to be enabled");
      }
      
      // Write files
      await writeFile("config.json", JSON.stringify(reactRouterConfig));
      
      // Set up platform-specific configuration
      await setupDeployment(reactRouterConfig);
    },
  };
}

Configuration Merging

Presets are merged in order with user config:

export default {
  presets: [
    presetA(), // Applied first
    presetB(), // Applied second
  ],
  
  // User config takes priority
  buildDirectory: "custom-build",
} satisfies Config;

Merge order:

1. Preset A config
2. Preset B config (overrides A)
3. User config (overrides presets)

Excluded Keys

The presets key itself cannot be set by presets:

// ❌ Not allowed
export function myPreset(): Preset {
  return {
    reactRouterConfig() {
      return {
        presets: [anotherPreset()], // Error!
      };
    },
  };
}

Build Hooks

Use buildEnd for post-build operations:

export function deploymentPreset(): Preset {
  return {
    name: "deployment-preset",
    
    reactRouterConfig() {
      return {
        async buildEnd({ buildManifest, reactRouterConfig, viteConfig }) {
          console.log("Deploying to production...");
          
          // Access build output
          const routes = Object.keys(buildManifest.routes);
          console.log(`Built ${routes.length} routes`);
          
          // Read build files
          const clientDir = path.join(
            reactRouterConfig.buildDirectory,
            "client"
          );
          const files = await fs.readdir(clientDir, { recursive: true });
          
          // Deploy to CDN
          await uploadToCDN(files);
          
          // Deploy server
          const serverFile = path.join(
            reactRouterConfig.buildDirectory,
            "server",
            reactRouterConfig.serverBuildFile
          );
          await deployServer(serverFile);
          
          console.log("Deployment complete!");
        },
      };
    },
  };
}

Platform-Specific Examples

Custom Server Adapter

import type { Preset } from "@react-router/dev/config";
import fs from "node:fs/promises";

export function customServerPreset(): Preset {
  return {
    name: "custom-server",
    
    reactRouterConfig() {
      return {
        serverModuleFormat: "esm",
        
        async buildEnd({ reactRouterConfig }) {
          // Generate server adapter
          const adapterCode = `
import { createRequestHandler } from "@react-router/express";
import express from "express";
import * as build from "./server/index.js";

const app = express();
app.use(express.static("build/client"));
app.all("*", createRequestHandler({ build }));

const port = process.env.PORT || 3000;
app.listen(port, () => {
  console.log(\`Server running on port \${port}\`);
});
          `;
          
          await fs.writeFile(
            path.join(reactRouterConfig.buildDirectory, "server.js"),
            adapterCode
          );
        },
      };
    },
  };
}

Docker Deployment

export function dockerPreset(): Preset {
  return {
    name: "docker",
    
    async reactRouterConfigResolved({ reactRouterConfig }) {
      // Generate Dockerfile
      const dockerfile = `
FROM node:20-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci --production
COPY ${reactRouterConfig.buildDirectory} ./build
EXPOSE 3000
CMD ["node", "build/server/index.js"]
      `;
      
      await fs.writeFile("Dockerfile", dockerfile);
      
      // Generate .dockerignore
      const dockerignore = `
node_modules
.git
*.log
.env
      `;
      
      await fs.writeFile(".dockerignore", dockerignore);
    },
  };
}

Validation

Validate user configuration in presets:

export function validatedPreset(): Preset {
  return {
    name: "validated",
    
    async reactRouterConfigResolved({ reactRouterConfig }) {
      // Require SSR
      if (!reactRouterConfig.ssr) {
        throw new Error("This preset requires SSR to be enabled");
      }
      
      // Require specific module format
      if (reactRouterConfig.serverModuleFormat !== "esm") {
        throw new Error("This preset requires ESM module format");
      }
      
      // Check for required environment variables
      if (!process.env.DEPLOY_TOKEN) {
        throw new Error("DEPLOY_TOKEN environment variable is required");
      }
    },
  };
}

Multiple Presets

Combine multiple presets:

import { cloudflarePreset } from "@react-router/cloudflare";
import { analyticsPreset } from "./presets/analytics";
import { monitoringPreset } from "./presets/monitoring";

export default {
  presets: [
    cloudflarePreset(),
    analyticsPreset(),
    monitoringPreset(),
  ],
} satisfies Config;

Preset Options

Allow configuration of presets:

interface MyPresetOptions {
  apiKey?: string;
  region?: "us" | "eu";
}

export function myPreset(options: MyPresetOptions = {}): Preset {
  return {
    name: "my-preset",
    
    reactRouterConfig() {
      return {
        async buildEnd() {
          const apiKey = options.apiKey || process.env.API_KEY;
          const region = options.region || "us";
          
          await deployTo(region, { apiKey });
        },
      };
    },
  };
}

Usage:

export default {
  presets: [
    myPreset({
      apiKey: "...",
      region: "eu",
    }),
  ],
} satisfies Config;

See Also

• Vite Plugin
• Server Bundles
• Server Rendering