Simple link shortening service

Quick start

1. Pick a strong shared secret and export it before starting the server:

   export SHORTENER_SECRET="replace-with-a-random-string"
   php -S 0.0.0.0:8080 -t webroot

2. Create a short link with an authenticated API call:

   SECRET="$SHORTENER_SECRET"
   TIMESTAMP=$(date -u +%s)
   BODY='{"url":"https://example.org"}'
   CANONICAL=$(printf "%s\n%s\n%s\n%s" "$TIMESTAMP" "POST" "/api/shorten" "$BODY")
   SIGNATURE=$(printf "%s" "$CANONICAL" | openssl dgst -sha256 -mac HMAC -macopt "key:$SECRET" -binary | base64)
   
   curl -X POST http://127.0.0.1:8080/api/shorten \
     -H "Content-Type: application/json" \
     -H "X-Timestamp: $TIMESTAMP" \
     -H "X-Signature: $SIGNATURE" \
     -d "$BODY"

   The signature is calculated as base64(hmac_sha256(timestamp + "\n" + METHOD + "\n" + PATH + "\n" + body, secret)) and requests are only accepted when the timestamp is within five minutes of the server time.

3. Resolve a short link (no authentication required):

   curl -i http://127.0.0.1:8080/abc

PowerShell helper

Import-Module "$PSScriptRoot/powershell/ShortenerClient.psm1"
$env:SHORTENER_SECRET = "replace-with-a-random-string"

New-ShortLink -Url "https://example.org" -ApiBaseUrl "http://127.0.0.1:8080"
Get-ShortLink -Code "abc" -ApiBaseUrl "http://127.0.0.1:8080"

Docker

Run the API with Docker Compose:

export SHORTENER_SECRET="replace-with-a-random-string"
docker compose up --build

The service listens on http://localhost:8080 and stores its SQLite database in ./data/shortener.sqlite on the host.

API

• POST /api/shorten (authenticated) accepts {"url": "https://target"} and returns the code, short_url, target_url, and created_at fields.
• GET /api/links/{code} (authenticated) returns metadata about an existing short link.
• GET /{code} (public) issues an HTTP redirect to the stored target URL.

Links are stored in data/shortener.sqlite using SQLite. The database and schema are created automatically on first run.