Redirects - Ensemble Edge

Starter Kit - Ships with your template. You own it - modify freely.

Overview

The redirect system provides enterprise-grade URL shortening with three link types:

Permanent: Traditional short links that never expire
Expiring: Time-limited links with automatic cleanup
Single-use: Magic links for secure one-time access

All redirect data is stored in Cloudflare KV with automatic TTL management.

Quick Start

1. Create a Redirect

curl -X POST https://your-app.com/api/v1/redirects \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "targetUrl": "https://example.com/destination",
    "type": "permanent"
  }'

Response:

{
  "success": true,
  "data": {
    "slug": "abc123",
    "shortUrl": "https://your-app.com/go/abc123",
    "targetUrl": "https://example.com/destination",
    "type": "permanent",
    "statusCode": 302,
    "used": false,
    "createdAt": "2024-01-15T10:30:00.000Z"
  }
}

2. Use the Short Link

curl https://your-app.com/go/abc123
# Redirects to: https://example.com/destination

3. Manage Redirects

# Get redirect details
curl https://your-app.com/api/v1/redirects/abc123 \
  -H "Authorization: Bearer YOUR_TOKEN"

# List all redirects
curl https://your-app.com/api/v1/redirects \
  -H "Authorization: Bearer YOUR_TOKEN"

# Update redirect
curl -X PUT https://your-app.com/api/v1/redirects/abc123 \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "targetUrl": "https://example.com/new-destination"
  }'

# Delete redirect
curl -X DELETE https://your-app.com/api/v1/redirects/abc123 \
  -H "Authorization: Bearer YOUR_TOKEN"

Ensembles

The redirect system consists of two ensembles:

Resolve Ensemble

File: ensembles/system/redirects/resolve.yaml Handles public redirect resolution at /go/:slug.

name: redirect-resolver
version: 1.0.0
description: Resolve short links and redirect to target URL

trigger:
  - type: http
    path: /go/:slug
    methods: [GET, HEAD]
    public: true
    priority: -100  # Low priority - checked after explicit routes

agents:
  - name: lookup
    agent: redirect
    input:
      action: resolve
      slug: ${{ trigger.params.slug }}
      markAsUsed: true
    config:
      kvBinding: REDIRECTS_KV
      basePath: /go

output:
  # Success: HTTP redirect
  - when: ${{ agents.lookup.output.found == true }}
    redirect:
      url: ${{ agents.lookup.output.targetUrl }}
      status: ${{ agents.lookup.output.statusCode }}

  # Not found
  - when: ${{ agents.lookup.output.error == 'not_found' }}
    status: 404
    body:
      success: false
      error: not_found
      message: "Redirect not found"

  # Expired
  - when: ${{ agents.lookup.output.error == 'expired' }}
    status: 410
    body:
      success: false
      error: expired
      message: "This link has expired"

  # Already used (single-use)
  - when: ${{ agents.lookup.output.error == 'already_used' }}
    status: 410
    body:
      success: false
      error: already_used
      message: "This link has already been used"

  # KV binding not found
  - when: ${{ agents.lookup.output.error == 'binding_not_found' }}
    status: 500
    body:
      success: false
      error: configuration_error
      message: "Redirect service not configured"

Key Features:

Public access (no authentication)
Automatic single-use link marking
Comprehensive error handling
Low route priority (doesn’t override explicit routes)

API Ensemble

File: ensembles/system/redirects/api.yaml Provides authenticated CRUD operations at /api/v1/redirects.

name: redirect-api
version: 1.0.0
description: Management API for redirects (CRUD operations)

trigger:
  - type: http
    paths:
      - path: /api/v1/redirects
        methods: [GET, POST]
      - path: /api/v1/redirects/:slug
        methods: [GET, PUT, DELETE]
    auth:
      requirement: required
      methods: [bearer, apiKey]

agents:
  - name: manage
    agent: redirect
    input:
      # Determine action from HTTP method and path
      action: ${{
        trigger.method == 'GET' && !trigger.params.slug ? 'list' :
        trigger.method == 'GET' && trigger.params.slug ? 'get' :
        trigger.method == 'POST' ? 'create' :
        trigger.method == 'PUT' ? 'update' :
        trigger.method == 'DELETE' ? 'delete' : 'get'
      }}

      # For get/update/delete
      slug: ${{ trigger.params.slug }}

      # For create/update (from request body)
      targetUrl: ${{ trigger.body.targetUrl }}
      type: ${{ trigger.body.type }}
      statusCode: ${{ trigger.body.statusCode }}
      expiresIn: ${{ trigger.body.expiresIn }}
      expiresAt: ${{ trigger.body.expiresAt }}
      customSlug: ${{ trigger.body.slug }}
      metadata: ${{ trigger.body.metadata }}

      # For list (from query params)
      filter:
        type: ${{ trigger.query.type }}
        used: ${{ trigger.query.used }}
        campaign: ${{ trigger.query.campaign }}
      limit: ${{ trigger.query.limit }}
      cursor: ${{ trigger.query.cursor }}

    config:
      kvBinding: REDIRECTS_KV
      basePath: /go
      defaultStatusCode: 302
      defaultType: permanent

output:
  # Create: 201 Created
  - when: ${{ agents.manage.output.success && trigger.method == 'POST' }}
    status: 201
    body:
      success: true
      data: ${{ agents.manage.output.redirect }}

  # Delete: 204 No Content
  - when: ${{ agents.manage.output.success && trigger.method == 'DELETE' }}
    status: 204

  # Get/Update: 200 OK with single redirect
  - when: ${{ agents.manage.output.success && agents.manage.output.redirect }}
    status: 200
    body:
      success: true
      data: ${{ agents.manage.output.redirect }}

  # List: 200 OK with array
  - when: ${{ agents.manage.output.success && agents.manage.output.redirects }}
    status: 200
    body:
      success: true
      data: ${{ agents.manage.output.redirects }}
      pagination:
        cursor: ${{ agents.manage.output.cursor }}
        total: ${{ agents.manage.output.total }}

  # Error cases...
  - when: ${{ agents.manage.output.error == 'not_found' }}
    status: 404
    body:
      success: false
      error: not_found
      message: "Redirect not found"

Key Features:

RESTful API design
Authentication required
Supports all CRUD operations
Pagination for list endpoint
Filter by type, used status, campaign

Agent Reference

redirect Agent

File: agents/system/redirect/redirect.yaml The core redirect agent that powers both ensembles.

Input Schema

action:
  type: string
  enum: [resolve, create, get, update, delete, list]
  required: true
  description: Operation to perform

# For resolve/get/update/delete
slug:
  type: string
  description: The short code to look up

# For create/update
targetUrl:
  type: string
  format: uri
  description: Destination URL

type:
  type: string
  enum: [permanent, expiring, single-use]
  default: permanent

statusCode:
  type: integer
  enum: [301, 302, 307, 308]
  default: 302

expiresAt:
  type: string
  format: date-time
  description: Expiration timestamp (ISO 8601)

expiresIn:
  type: integer
  description: Seconds until expiration (alternative to expiresAt)

customSlug:
  type: string
  description: Custom slug (auto-generates if not provided)

metadata:
  type: object
  properties:
    createdBy:
      type: string
    campaign:
      type: string
    tags:
      type: array
      items:
        type: string
    notes:
      type: string

# For list
filter:
  type: object
  properties:
    type:
      type: string
      enum: [permanent, expiring, single-use]
    used:
      type: boolean
    campaign:
      type: string

limit:
  type: integer
  default: 50

cursor:
  type: string

# For resolve
markAsUsed:
  type: boolean
  default: true
  description: Mark single-use links as used

Output Schema

success:
  type: boolean

found:
  type: boolean

targetUrl:
  type: string

statusCode:
  type: integer

error:
  type: string
  enum: [not_found, expired, already_used, slug_taken, invalid_url, binding_not_found]

errorMessage:
  type: string

redirect:
  type: object
  description: Single redirect entry

redirects:
  type: array
  description: Array of redirect entries

cursor:
  type: string
  description: Pagination cursor

total:
  type: integer
  description: Total results count

Configuration Schema

kvBinding:
  type: string
  default: REDIRECTS_KV
  description: KV namespace binding name

basePath:
  type: string
  default: /go
  description: Base path for shortUrl computation

defaultStatusCode:
  type: integer
  enum: [301, 302, 307, 308]
  default: 302

defaultType:
  type: string
  enum: [permanent, expiring, single-use]
  default: permanent

slugLength:
  type: integer
  default: 7
  description: Generated slug length

slugAlphabet:
  type: string
  default: "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
  description: Characters for slug generation

Configuration

1. Add KV Binding

Add to your wrangler.toml:

[[kv_namespaces]]
binding = "REDIRECTS_KV"
id = "your-kv-namespace-id"

Create the KV namespace:

wrangler kv:namespace create "REDIRECTS_KV"

2. Configure Base Path

The default base path is /go. To customize:

# In your ensemble
agents:
  - name: redirect-agent
    agent: redirect
    config:
      basePath: /r  # Use /r instead of /go

3. Configure Slug Generation

# In your ensemble
agents:
  - name: redirect-agent
    agent: redirect
    config:
      slugLength: 10  # Longer slugs
      slugAlphabet: "0123456789abcdefghijklmnopqrstuvwxyz"  # Lowercase only

4. Set Default Redirect Type

# In your ensemble
agents:
  - name: redirect-agent
    agent: redirect
    config:
      defaultType: expiring  # Default to expiring links
      defaultStatusCode: 301  # Use permanent redirect

Examples

Permanent Link

agents:
  - name: create
    agent: redirect
    input:
      action: create
      targetUrl: "https://example.com/page"
      type: permanent
      customSlug: "mylink"
    config:
      kvBinding: REDIRECTS_KV

Output:

{
  "success": true,
  "redirect": {
    "slug": "mylink",
    "shortUrl": "https://your-app.com/go/mylink",
    "targetUrl": "https://example.com/page",
    "type": "permanent",
    "statusCode": 302,
    "used": false,
    "createdAt": "2024-01-15T10:30:00.000Z"
  }
}

Expiring Link (24 hours)

agents:
  - name: create
    agent: redirect
    input:
      action: create
      targetUrl: "https://example.com/promo"
      type: expiring
      expiresIn: 86400  # 24 hours in seconds
      metadata:
        campaign: "spring-sale"
    config:
      kvBinding: REDIRECTS_KV

Output:

{
  "success": true,
  "redirect": {
    "slug": "p7xK9mQ",
    "shortUrl": "https://your-app.com/go/p7xK9mQ",
    "targetUrl": "https://example.com/promo",
    "type": "expiring",
    "expiresAt": "2024-01-16T10:30:00.000Z",
    "statusCode": 302,
    "metadata": {
      "campaign": "spring-sale"
    }
  }
}

Single-Use Magic Link

agents:
  - name: create
    agent: redirect
    input:
      action: create
      targetUrl: "https://app.com/onboard?token=xyz"
      type: single-use
      expiresIn: 3600  # 1 hour
      metadata:
        createdBy: "system"
        campaign: "welcome-email"
    config:
      kvBinding: REDIRECTS_KV

Output:

{
  "success": true,
  "redirect": {
    "slug": "m7kP2xQ",
    "shortUrl": "https://your-app.com/go/m7kP2xQ",
    "targetUrl": "https://app.com/onboard?token=xyz",
    "type": "single-use",
    "expiresAt": "2024-01-15T11:30:00.000Z",
    "statusCode": 302,
    "used": false,
    "usedAt": null,
    "metadata": {
      "createdBy": "system",
      "campaign": "welcome-email"
    }
  }
}

Resolve Without Marking Used

Useful for previewing or analytics:

agents:
  - name: lookup
    agent: redirect
    input:
      action: resolve
      slug: "m7kP2xQ"
      markAsUsed: false  # Don't consume single-use link
    config:
      kvBinding: REDIRECTS_KV

List with Filters

agents:
  - name: list
    agent: redirect
    input:
      action: list
      filter:
        type: single-use
        used: false
        campaign: "welcome-email"
      limit: 100
    config:
      kvBinding: REDIRECTS_KV

Output:

{
  "success": true,
  "redirects": [
    {
      "slug": "m7kP2xQ",
      "shortUrl": "https://your-app.com/go/m7kP2xQ",
      "targetUrl": "https://app.com/onboard?token=xyz",
      "type": "single-use",
      "used": false,
      "metadata": {
        "campaign": "welcome-email"
      }
    }
  ],
  "cursor": "next-page-token",
  "total": 1
}

Update Redirect

agents:
  - name: update
    agent: redirect
    input:
      action: update
      slug: "mylink"
      targetUrl: "https://example.com/new-page"
      expiresIn: 7200  # Extend expiration
    config:
      kvBinding: REDIRECTS_KV

Delete Redirect

agents:
  - name: delete
    agent: redirect
    input:
      action: delete
      slug: "mylink"
    config:
      kvBinding: REDIRECTS_KV

Customization

Change Slug Algorithm

Edit agents/system/redirect/redirect.ts:

function customAlphabet(alphabet: string, size: number): string {
  // Replace with your preferred algorithm
  // Options:
  // - UUID: crypto.randomUUID()
  // - Base62: Custom base62 encoding
  // - Hashids: Hash-based IDs
  // - Sequential: Counter-based

  const array = new Uint8Array(size)
  crypto.getRandomValues(array)
  let result = ''
  for (let i = 0; i < size; i++) {
    result += alphabet[array[i] % alphabet.length]
  }
  return result
}

Add Analytics Tracking

Edit agents/system/redirect/redirect.ts in the resolve function:

async function resolve(
  kv: KVNamespace,
  input: RedirectInput,
  ctx: AgentExecutionContext,
  config: RedirectConfig
): Promise<RedirectOutput> {
  // ... existing code ...

  // Add analytics tracking
  if (entry) {
    await logRedirectEvent(ctx, {
      slug: input.slug,
      targetUrl: entry.targetUrl,
      timestamp: new Date().toISOString(),
      userAgent: ctx.request?.headers.get('user-agent'),
      referer: ctx.request?.headers.get('referer'),
    })
  }

  return {
    success: true,
    found: true,
    targetUrl: entry.targetUrl,
    statusCode: entry.statusCode,
  }
}

Add Custom Metadata Fields

Edit agents/system/redirect/redirect.yaml:

schema:
  input:
    properties:
      metadata:
        type: object
        properties:
          createdBy:
            type: string
          campaign:
            type: string
          tags:
            type: array
          # Add your custom fields
          department:
            type: string
          region:
            type: string
          customId:
            type: string

Custom Error Pages

Edit ensembles/system/redirects/resolve.yaml:

output:
  # Not found - redirect to custom 404
  - when: ${{ agents.lookup.output.error == 'not_found' }}
    redirect:
      url: /404?slug=${{ trigger.params.slug }}
      status: 302

  # Expired - show custom page
  - when: ${{ agents.lookup.output.error == 'expired' }}
    redirect:
      url: /expired
      status: 302

Add Rate Limiting

trigger:
  - type: http
    path: /api/v1/redirects
    methods: [POST]
    auth:
      requirement: required
    rateLimit:
      requests: 10
      window: 60  # 10 requests per minute

Add Webhook Notifications

agents:
  - name: create
    agent: redirect
    input:
      action: create
      targetUrl: ${{ input.targetUrl }}
      type: ${{ input.type }}

  - name: notify
    condition: ${{ agents.create.output.success }}
    operation: http
    config:
      url: ${{ env.WEBHOOK_URL }}
      method: POST
      body:
        event: redirect_created
        data: ${{ agents.create.output.redirect }}

Common Use Cases

Email Campaign Links

agents:
  - name: create-campaign-links
    agent: redirect
    input:
      action: create
      targetUrl: "https://example.com/promo"
      type: expiring
      expiresIn: 604800  # 7 days
      metadata:
        campaign: "summer-2024"
        channel: "email"
        createdBy: "marketing-automation"

Password Reset Links

agents:
  - name: create-reset-link
    agent: redirect
    input:
      action: create
      targetUrl: "https://app.com/reset?token=${{ input.resetToken }}"
      type: single-use
      expiresIn: 3600  # 1 hour
      metadata:
        userId: "${{ input.userId }}"
        purpose: "password-reset"

QR Code Links

agents:
  - name: create-qr-link
    agent: redirect
    input:
      action: create
      targetUrl: "https://example.com/menu"
      type: permanent
      customSlug: "menu-table-5"
      statusCode: 301
      metadata:
        location: "restaurant"
        table: "5"

A/B Testing

agents:
  - name: create-variant-a
    agent: redirect
    input:
      action: create
      targetUrl: "https://example.com/landing-a"
      customSlug: "promo"
      metadata:
        variant: "a"

  - name: create-variant-b
    agent: redirect
    input:
      action: create
      targetUrl: "https://example.com/landing-b"
      customSlug: "promo-b"
      metadata:
        variant: "b"

Best Practices

1. Choose the Right Link Type

Permanent: Public links, documentation, long-term campaigns
Expiring: Time-sensitive promotions, temporary access
Single-use: Magic links, password resets, secure tokens

2. Set Appropriate Expiration Times

expiresIn: 300      # 5 minutes - OTP codes
expiresIn: 3600     # 1 hour - password resets
expiresIn: 86400    # 24 hours - daily deals
expiresIn: 604800   # 7 days - email campaigns
expiresIn: 2592000  # 30 days - monthly access

3. Use Metadata for Organization

metadata:
  campaign: "spring-sale-2024"
  channel: "email"
  segment: "premium-users"
  createdBy: "marketing-automation"
  region: "us-west"

4. Choose Status Codes Wisely

301: Permanent redirect (cached by browsers)
302: Temporary redirect (default, allows updates)
307: Temporary redirect (preserves HTTP method)
308: Permanent redirect (preserves HTTP method)

5. Implement Analytics

Track redirect usage:

Click counts
Geographic distribution
Device types
Referrer sources
Time-based patterns

6. Monitor and Clean Up

List unused redirects periodically
Remove expired redirects manually if needed
Archive old campaign data
Monitor KV storage usage

7. Secure Custom Slugs

# Bad - guessable
customSlug: "admin"
customSlug: "reset-password"

# Good - random or namespaced
customSlug: "admin-x9K2p"
customSlug: "reset-pwd-m7kP2xQ"

Error Handling

All errors include descriptive messages:

// Not found
{
  "success": true,
  "found": false,
  "error": "not_found"
}

// Expired
{
  "success": true,
  "found": false,
  "error": "expired"
}

// Already used
{
  "success": true,
  "found": false,
  "error": "already_used"
}

// Slug taken
{
  "success": false,
  "error": "slug_taken",
  "errorMessage": "Slug \"mylink\" already exists"
}

// Invalid URL
{
  "success": false,
  "error": "invalid_url",
  "errorMessage": "Invalid targetUrl format"
}

// Configuration error
{
  "success": false,
  "error": "binding_not_found",
  "errorMessage": "KV binding \"REDIRECTS_KV\" not found"
}

Next Steps

Slug Generator

Generate URL-safe slugs

Starter Kit Overview

Explore other starter kit components

KV Storage

Learn about Cloudflare KV

Triggers

Trigger configuration

​Overview

​Quick Start

​1. Create a Redirect

​2. Use the Short Link

​3. Manage Redirects

​Ensembles

​Resolve Ensemble

​API Ensemble

​Agent Reference

​redirect Agent

​Input Schema

​Output Schema

​Configuration Schema

​Configuration

​1. Add KV Binding

​2. Configure Base Path

​3. Configure Slug Generation

​4. Set Default Redirect Type

​Examples

​Permanent Link

​Expiring Link (24 hours)

​Single-Use Magic Link

​Resolve Without Marking Used

​List with Filters

​Update Redirect

​Delete Redirect

​Customization

​Change Slug Algorithm

​Add Analytics Tracking

​Add Custom Metadata Fields

​Custom Error Pages

​Add Rate Limiting

​Add Webhook Notifications

​Common Use Cases

​Email Campaign Links

​Password Reset Links

​QR Code Links

​A/B Testing

​Best Practices

​1. Choose the Right Link Type

​2. Set Appropriate Expiration Times

​3. Use Metadata for Organization

​4. Choose Status Codes Wisely

​5. Implement Analytics

​6. Monitor and Clean Up

​7. Secure Custom Slugs

​Error Handling

​Next Steps

Slug Generator

Starter Kit Overview

KV Storage

Triggers

Overview

Quick Start

1. Create a Redirect

2. Use the Short Link

3. Manage Redirects

Ensembles

Resolve Ensemble

API Ensemble

Agent Reference

redirect Agent

Input Schema

Output Schema

Configuration Schema

Configuration

1. Add KV Binding

2. Configure Base Path

3. Configure Slug Generation

4. Set Default Redirect Type

Examples

Permanent Link

Expiring Link (24 hours)

Single-Use Magic Link

Resolve Without Marking Used

List with Filters

Update Redirect

Delete Redirect

Customization

Change Slug Algorithm

Add Analytics Tracking

Add Custom Metadata Fields

Custom Error Pages

Add Rate Limiting

Add Webhook Notifications

Common Use Cases

Email Campaign Links

Password Reset Links

QR Code Links

A/B Testing

Best Practices

1. Choose the Right Link Type

2. Set Appropriate Expiration Times

3. Use Metadata for Organization

4. Choose Status Codes Wisely

5. Implement Analytics

6. Monitor and Clean Up

7. Secure Custom Slugs

Error Handling

Next Steps