Route Patterns

Reference: Fast Router GitHub Repository

Deserve uses Fast Router (radix tree) for route matching and parameter extraction. File paths in the routes folder are turned into patterns; dynamic segments use [param], which becomes :param at the router level.

Pattern Matching

Deserve converts file paths to route patterns. FastRouter handles pattern matching with radix tree for optimal performance:

.
├── routes/index.ts              → /
├── routes/about.ts              → /about
├── routes/users/[id].ts         → /users/:id
├── routes/users/[id]/posts.ts   → /users/:id/posts

Dynamic Parameters

Use [param] syntax for dynamic route segments:

Single Parameter

// File: routes/users/[id].ts
// 1. Import Context
import type { Context } from '@neabyte/deserve'

// 2. GET /users/:id — get param from ctx.param('id')
export function GET(ctx: Context): Response {
  const id = ctx.param('id')
  return ctx.send.json({ userId: id })
}

Multiple Parameters

// File: routes/users/[id]/posts/[postId].ts
// 1. One ctx.param per dynamic segment
import type { Context } from '@neabyte/deserve'

export function GET(ctx: Context): Response {
  const id = ctx.param('id')
  const postId = ctx.param('postId')
  return ctx.send.json({ userId: id, postId })
}

Nested Parameters

// File: routes/api/v1/users/[userId]/posts/[postId]/comments/[commentId].ts
// 1. Each [param] in path → ctx.param('param')
import type { Context } from '@neabyte/deserve'

export function GET(ctx: Context): Response {
  const userId = ctx.param('userId')
  const postId = ctx.param('postId')
  const commentId = ctx.param('commentId')
  return ctx.send.json({ userId, postId, commentId })
}

Pattern Examples

User Management

routes/
├── users.ts                       → /users
├── users/[id].ts                  → /users/:id
├── users/[id]/profile.ts          → /users/:id/profile
├── users/[id]/posts.ts            → /users/:id/posts
└── users/[id]/posts/[postId].ts   → /users/:id/posts/:postId

API Versioning

routes/
├── api/
│   ├── v1/
│   │   └── users/[id].ts          → /api/v1/users/:id
│   └── v2/
│       └── users/[id].ts          → /api/v2/users/:id

Blog System

routes/
├── blog/
│   ├── [slug].ts                  → /blog/:slug
│   └── [year]/
│       └── [month]/
│           └── [day]/
│               └── [slug].ts      → /blog/:year/:month/:day/:slug

Parameter Validation

Extract and validate parameters in your route handlers:

// File: routes/users/[id].ts
// 1. Get param then validate; if invalid → 400
import type { Context } from '@neabyte/deserve'

// GET /users/:id
export function GET(ctx: Context): Response {
  const id = ctx.param('id')
  if (!id || !/^\d+$/.test(id)) {
    return ctx.send.json({ error: 'Invalid user ID' }, { status: 400 })
  }
  return ctx.send.json({ userId: parseInt(id) })
}