day-3

Day 3: Deploy Your Agent to Railway

Goal: Deploy your Day 2 agent (with memory and tools) to the cloud using Railway, making it accessible via REST API from anywhere.

Quick Start

# 1. Login to Railway
railway login

# 2. Create a new project
cd day-3
railway init
# Enter a name for your project when prompted

# 3. Link to your project
railway link

# 4. Deploy (will fail - that's expected!)
railway up

# 5. Add your OpenAI API key
# Go to railway.app → Your Service → Variables → Add OPENAI_API_KEY

# 6. Deploy again (now it will work!)
railway up

# 7. Get your URL
railway domain

# 8. Test it
curl https://your-url.up.railway.app/health

Prerequisites

1. Railway Account: Sign up at railway.app
2. Railway CLI: Install Railway CLI

   # macOS/Linux
   curl -fsSL https://railway.app/install.sh | sh
   
   # Or via npm
   npm install -g @railway/cli

3. OpenAI API Key: From Day 1-2

Add Environment Variables

Now add your OpenAI API key so the agent can work.

Option A: Via Railway Dashboard

1. Go to railway.app
2. Click your project → Click your service
3. Go to Variables tab
4. Click + New Variable
5. Add OPENAI_API_KEY with your key value
6. (Optional) Add SERPER_API_KEY for web search tool
7. Railway automatically redeploys

Option B: Via CLI

# Set environment variables AFTER first deploy
railway variables --set "OPENAI_API_KEY=your-key-here"

# Optional: Add SERPER_API_KEY for web search
railway variables --set "SERPER_API_KEY=your-serper-key"

# Deploy again with variables
railway up

What Railway does:

1. Reads railway.json for config
2. Installs packages from requirements.txt
3. Starts your FastAPI server
4. Gives you a public URL

Get Your Public URL

After deployment completes (takes 2-3 minutes):

Option A: CLI

railway domain

Option B: Dashboard

• Go to railway.app → Your service → "Settings" tab
• Look for "Public URL" or click "Generate Domain"

Example output:

https://day-3-agent-production.up.railway.app

Save this URL - you'll use it to interact with your agent.

Testing Your Deployed Agent

Test 1: Health Check

curl https://your-app.up.railway.app/health

Expected response:

{
  "status": "healthy",
  "memory_enabled": true,
  "tools_count": 5
}

Test 2: Query Your Agent

curl -X POST https://your-app.up.railway.app/query \
  -H "Content-Type: application/json" \
  -d '{"question": "What is 123 * 456?"}'

Expected response:

{
  "answer": "The result of 123 * 456 is 56,088.",
  "timestamp": "2026-01-24T10:30:00Z",
  "processing_time": 2.5
}

Test 3: Test Memory

# First request - tell the agent something
curl -X POST https://your-app.up.railway.app/query \
  -H "Content-Type: application/json" \
  -d '{"question": "My name is Alex and I love Python"}'

# Second request - see if it remembers
curl -X POST https://your-app.up.railway.app/query \
  -H "Content-Type: application/json" \
  -d '{"question": "What is my name?"}'

Expected: Agent should remember your name from the first request.