Serverless Functions

Deploy individual functions as HTTP endpoints with zero infrastructure management. Functions scale to zero when idle, boot in milliseconds, and bill per invocation -- ideal for webhooks, scheduled tasks, lightweight APIs, and event handlers.

Use cases

Use Case	Description
Webhooks	Handle Stripe, GitHub, or any third-party webhook with zero cold-start concern.
Cron tasks	Run scheduled data jobs, reports, or cleanup routines without a persistent process.
API endpoints	Lightweight REST endpoints that only run when called.
Event handlers	React to RailPush deploy events, queue messages, or database triggers.

Supported runtimes

• Node.js 20
• Python 3.11

Limits

Limit	Value
Execution timeout	30 seconds
Memory	512 MB
Request payload	6 MB
Concurrency	Unlimited (scale to zero)

Create a function

API

curl -X POST https://railpush.com/api/v1/functions \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "process-webhook",
    "runtime": "node20",
    "source_type": "git",
    "repo": "acme/webhooks",
    "branch": "main",
    "handler": "index.handler"
  }'

# Response:
# {
#   "id": "fn-...",
#   "invoke_url": "https://fn-process-webhook.railpush.com",
#   "status": "deploying"
# }

Invoke a function

curl

# HTTP POST with JSON body
curl -X POST https://fn-process-webhook.railpush.com \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <token>" \
  -d '{"event": "payment.succeeded", "amount": 4900}'

# HTTP GET with query params
curl "https://fn-process-webhook.railpush.com?id=123"

API reference

Method	Endpoint	Description
POST	/api/v1/functions	Create a function
GET	/api/v1/functions	List all functions
GET	/api/v1/functions/:id	Get function details
PATCH	/api/v1/functions/:id	Update function config
DELETE	/api/v1/functions/:id	Delete a function
POST	/api/v1/functions/:id/invoke	Invoke synchronously (returns response)