Wrangler Workflows

Wrangler Workflows

Purpose

This skill provides comprehensive guidance for using Wrangler, the Cloudflare Workers CLI tool. It covers common commands, configuration file management, local development workflows, secrets handling, and deployment processes. Use this skill when working with Wrangler CLI operations, configuring Workers projects, or managing Workers deployments.

Wrangler Overview

Wrangler is the official CLI tool for Cloudflare Workers. It handles:

• Project initialization and scaffolding
• Local development and testing
• Configuration management
• Deployment and publishing
• Resource management (KV, D1, R2, etc.)
• Secrets and environment variables
• Logs and debugging

Installation

# Install globally via npm
npm install -g wrangler

# Or use npx (no install needed)
npx wrangler

# Verify installation
wrangler --version

Authentication

# Login to Cloudflare account
wrangler login

# Or use API token
export CLOUDFLARE_API_TOKEN=your-token
wrangler whoami

Common Commands

Development Commands

Start local development server:

# Local mode (uses local resources when possible)
wrangler dev

# Remote mode (uses remote resources)
wrangler dev --remote

# Custom port
wrangler dev --port 3000

# With live reload
wrangler dev --live-reload

Tail logs (real-time):

# Production logs
wrangler tail

# With filters
wrangler tail --status error
wrangler tail --method POST
wrangler tail --search "user-id"

# Pretty print
wrangler tail --format pretty

Deployment Commands

Deploy to Cloudflare:

# Deploy to production
wrangler deploy

# Deploy to specific environment
wrangler deploy --env staging
wrangler deploy --env production

# Dry run (validate without deploying)
wrangler deploy --dry-run

# Legacy command (same as deploy)
wrangler publish

Manage deployments:

# List deployments
wrangler deployments list

# View deployment details
wrangler deployments view [deployment-id]

# Rollback to previous deployment
wrangler rollback [deployment-id]

Resource Management

KV Commands:

# Create KV namespace
wrangler kv:namespace create NAMESPACE_NAME

# List namespaces
wrangler kv:namespace list

# Put key-value
wrangler kv:key put KEY "value" --namespace-id=xxx

# Get value
wrangler kv:key get KEY --namespace-id=xxx

# Delete key
wrangler kv:key delete KEY --namespace-id=xxx

# List keys
wrangler kv:key list --namespace-id=xxx

# Bulk operations
wrangler kv:bulk put data.json --namespace-id=xxx
wrangler kv:bulk delete keys.json --namespace-id=xxx

D1 Commands:

# Create database
wrangler d1 create DATABASE_NAME

# List databases
wrangler d1 list

# Execute SQL
wrangler d1 execute DB_NAME --command="SELECT * FROM users"
wrangler d1 execute DB_NAME --file=query.sql

# Remote mode (production)
wrangler d1 execute DB_NAME --remote --command="SELECT * FROM users"

# Migrations
wrangler d1 migrations create DB_NAME migration_name
wrangler d1 migrations list DB_NAME
wrangler d1 migrations apply DB_NAME
wrangler d1 migrations apply DB_NAME --remote

R2 Commands:

# Create bucket
wrangler r2 bucket create BUCKET_NAME

# List buckets
wrangler r2 bucket list

# Upload object
wrangler r2 object put BUCKET_NAME/key.txt --file=local-file.txt

# Download object
wrangler r2 object get BUCKET_NAME/key.txt --file=output.txt

# Delete object
wrangler r2 object delete BUCKET_NAME/key.txt

# List objects
wrangler r2 object list BUCKET_NAME

Secrets Management

# Add secret
wrangler secret put SECRET_NAME
# (prompts for value)

# List secrets
wrangler secret list

# Delete secret
wrangler secret delete SECRET_NAME

# Bulk secrets
wrangler secret bulk data.json

See references/wrangler-commands-cheatsheet.md for complete command reference.

Configuration Files

Wrangler supports two configuration formats:

1. wrangler.toml - TOML format (traditional)
2. wrangler.jsonc - JSON with comments (modern, recommended)

Basic wrangler.jsonc Structure

{
  "name": "my-worker",
  "main": "src/index.ts",
  "compatibility_date": "2024-01-01",

  // Environment variables
  "vars": {
    "ENVIRONMENT": "production"
  },

  // KV namespaces
  "kv_namespaces": [
    {
      "binding": "MY_KV",
      "id": "abc123..."
    }
  ],

  // D1 databases
  "d1_databases": [
    {
      "binding": "DB",
      "database_name": "my-db",
      "database_id": "xyz789..."
    }
  ],

  // R2 buckets
  "r2_buckets": [
    {
      "binding": "MY_BUCKET",
      "bucket_name": "uploads"
    }
  ],

  // Workers AI
  "ai": {
    "binding": "AI"
  }
}

Multi-Environment Configuration

{
  "name": "my-worker",
  "main": "src/index.ts",
  "compatibility_date": "2024-01-01",

  // Default (production) configuration
  "vars": {
    "ENVIRONMENT": "production"
  },
  "kv_namespaces": [
    {
      "binding": "CACHE",
      "id": "prod-id"
    }
  ],

  // Environment-specific overrides
  "env": {
    "staging": {
      "vars": {
        "ENVIRONMENT": "staging"
      },
      "kv_namespaces": [
        {
          "binding": "CACHE",
          "id": "staging-id"
        }
      ]
    },
    "development": {
      "vars": {
        "ENVIRONMENT": "development"
      },
      "kv_namespaces": [
        {
          "binding": "CACHE",
          "id": "dev-id"
        }
      ]
    }
  }
}

Deploy to specific environment:

wrangler deploy --env staging
wrangler deploy --env development

See references/wrangler-config-options.md for all configuration options and examples/wrangler-jsonc-template.jsonc for annotated template.

Local Development Workflow

Step 1: Initialize Project

# Create new project
npm create cloudflare@latest

# Or initialize in existing directory
npm init cloudflare

Step 2: Configure wrangler.jsonc

Create or update wrangler.jsonc with bindings, environment variables, and settings.

Step 3: Develop Locally

# Start dev server
wrangler dev

# Worker accessible at http://localhost:8787

Step 4: Test Locally

# Local KV (simulated)
wrangler dev

# Remote resources (real KV, D1, etc.)
wrangler dev --remote

Step 5: Deploy

# Deploy to production
wrangler deploy

Remote vs Local Mode

Local Mode (Default)

• Bindings are simulated locally where possible
• KV, Cache API work with local storage
• D1 uses local SQLite
• Vectorize and Workflows require --remote

wrangler dev

Remote Mode

• Uses actual Cloudflare resources
• All bindings work as in production
• May incur charges (AI, etc.)
• Required for Vectorize, Workflows, AI Gateway

wrangler dev --remote

Important: Some bindings like Vectorize don't support local mode and always require --remote.

Secrets Best Practices

Adding Secrets

# Interactive (secure, recommended)
wrangler secret put API_KEY

# From file (be careful)
wrangler secret put DB_PASSWORD < password.txt

# Bulk from JSON
cat secrets.json | wrangler secret bulk

Secrets vs Environment Variables

Rule: Never commit secrets to version control. Use wrangler secret put for sensitive data.

Debugging and Logs

Real-Time Logs

# Tail production logs
wrangler tail

# Filter by status
wrangler tail --status error
wrangler tail --status ok

# Filter by method
wrangler tail --method POST

# Search logs
wrangler tail --search "user-123"

# Multiple filters
wrangler tail --status error --method POST

Local Development Debugging

# Start with debugging
wrangler dev

# Console.log output visible in terminal
# Use Chrome DevTools for breakpoints

Console Output

In Worker code:

console.log('Info message', { data: 'value' });
console.error('Error:', error);
console.warn('Warning');

Visible in:

• wrangler dev terminal output
• wrangler tail for production
• Cloudflare Dashboard → Workers → Logs

TypeScript Support

Wrangler automatically supports TypeScript:

// src/index.ts
export interface Env {
  MY_KV: KVNamespace;
  DB: D1Database;
  API_KEY: string;
}

export default {
  async fetch(
    request: Request,
    env: Env,
    ctx: ExecutionContext
  ): Promise<Response> {
    const value = await env.MY_KV.get('key');
    return new Response(value);
  }
};

Install types:

npm install -D @cloudflare/workers-types

Update tsconfig.json:

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "ES2022",
    "lib": ["ES2022"],
    "types": ["@cloudflare/workers-types"]
  }
}

Common Workflows

New Project Setup

# 1. Create project
npm create cloudflare@latest my-worker

# 2. Navigate to project
cd my-worker

# 3. Install dependencies
npm install

# 4. Configure wrangler.jsonc
# (edit wrangler.jsonc)

# 5. Develop locally
wrangler dev

# 6. Deploy
wrangler deploy

Adding D1 Database

# 1. Create database
wrangler d1 create my-database

# 2. Add to wrangler.jsonc
# "d1_databases": [{ "binding": "DB", "database_id": "..." }]

# 3. Create migrations
wrangler d1 migrations create my-database create_users_table

# 4. Write SQL in migrations/0001_create_users_table.sql

# 5. Apply migrations locally
wrangler d1 migrations apply my-database

# 6. Apply to production
wrangler d1 migrations apply my-database --remote

Managing Multiple Environments

# Deploy to staging
wrangler deploy --env staging

# Tail staging logs
wrangler tail --env staging

# Execute on staging D1
wrangler d1 execute DB --env staging --remote --command="SELECT COUNT(*) FROM users"

# Deploy to production
wrangler deploy --env production

Troubleshooting

Common Issues

Issue: "Vectorize bindings not working in local dev"

• Solution: Use wrangler dev --remote, Vectorize doesn't support local mode

Issue: "Authentication failed"

• Solution: Run wrangler login or set CLOUDFLARE_API_TOKEN

Issue: "Binding not found in env"

• Solution: Check wrangler.jsonc configuration, ensure binding name matches

Issue: "D1 migrations not applying"

• Solution: Ensure you're using --remote flag for production: wrangler d1 migrations apply DB --remote

Issue: "Secrets not updating"

• Solution: Secrets require redeployment: wrangler secret put KEY then wrangler deploy

Getting Help

# General help
wrangler --help

# Command-specific help
wrangler dev --help
wrangler deploy --help
wrangler d1 --help

# Version info
wrangler --version

Best Practices

Configuration Management

• Use wrangler.jsonc for modern projects (JSON with comments)
• Commit wrangler.jsonc to version control
• Never commit secrets to git
• Use environment-specific configurations for staging/production
• Keep compatibility_date current

Development Workflow

• Always test with wrangler dev before deploying
• Use --remote when testing bindings that don't support local mode
• Run wrangler deploy --dry-run to validate before deploying
• Use wrangler tail to debug production issues
• Version control migrations (D1, Durable Objects)

Deployment Strategy

• Use environments for staging/production separation
• Test migrations in staging before production
• Use wrangler deployments list to track deployment history
• Keep Workers small and focused
• Monitor logs with wrangler tail after deployment

Security

• Always use wrangler secret put for sensitive data
• Rotate secrets regularly
• Use service bindings for internal-only Workers
• Validate all user input in Worker code
• Use HTTPS for external API calls

Additional Resources

Reference Files

For detailed information, consult:

• references/wrangler-commands-cheatsheet.md - Complete command reference with examples
• references/wrangler-config-options.md - All configuration options for wrangler.jsonc

Example Files

Working examples in examples/:

• wrangler-jsonc-template.jsonc - Comprehensive annotated configuration template

Documentation Links

For the latest Wrangler documentation:

• Wrangler commands: https://developers.cloudflare.com/workers/wrangler/commands/
• Configuration: https://developers.cloudflare.com/workers/wrangler/configuration/
• Migration guides: https://developers.cloudflare.com/workers/wrangler/migration/

Use the cloudflare-docs-specialist agent to search documentation and fetch the latest Wrangler information.