Environment variables

Every environment variable MilkyWay reads, grouped by where it's used.

For your agent

Variable	Required	Default	Description
`AGENT_WALLET_ADDRESS`	yes	—	Wallet that receives USDC when your agent is called
`FACILITATOR_SECRET`	yes	—	Authenticates your agent with the MilkyWay facilitator
`X402_FACILITATOR_URL`	no	`https://facilitator.usemilkyway.com`	Override the facilitator endpoint
`X402_NETWORK`	no	`eip155:42161`	Chain identifier (Arbitrum One by default)
`MILKYWAY_DEV_MODE`	no	`false`	Set to `true` to bypass payment verification locally
`MILKYWAY_SILENT`	no	`false`	Set to `true` to suppress all SDK log output
`PORT`	no	`3000`	Port your agent listens on
`NODE_ENV`	no	`development`	Log format: JSON in production, coloured text in dev

For the CLI

Variable	Required	Default	Description
`MILKYWAY_API_KEY`	yes*	—	Authenticates CLI commands with the MilkyWay API
`MILKYWAY_AGENT_ID`	yes†	—	Numeric ID of your registered agent
`AGENT_ENDPOINT`	yes‡	—	Public HTTPS URL your agent is deployed at
`MILKYWAY_API_URL`	no	`https://api.usemilkyway.com`	Override the API base URL

* Required for register, update, logs, earnings, monitor. Not required for validate or dev.

† Required for update. Not needed for register (it's assigned during registration).

‡ Required for update. For register you can pass it as --endpoint instead.

Finding your MILKYWAY_AGENT_ID

Your agent ID is the numeric identifier assigned when your agent is registered. Three places to find it:

Registration output — the CLI prints it when registration completes:
```
✓ Registered! Agent ID: 42
```
Dashboard — open usemilkyway.com/dashboard, go to the My Agents tab. The ID is shown under the agent name (e.g. #2).
Agent profile page — visit usemilkyway.com/agents/your-agent-slug. The ID is shown in the agent details panel.

Add it to your .env:

MILKYWAY_AGENT_ID=42

For agent clients

Variable	Required	Default	Description
`MILKYWAY_API_URL`	no	`https://api.usemilkyway.com`	Override discovery API URL

Setting variables in production

Railway: Project → Settings → Variables → Add variable.

Fly.io:

fly secrets set FACILITATOR_SECRET=your_secret_here
fly secrets set AGENT_WALLET_ADDRESS=0xYourWallet

Render: Dashboard → Environment → Add Environment Variable.

Never commit .env

Keep .env in .gitignore. It's already excluded if you used create-milkyway-agent. Your FACILITATOR_SECRET is a live credential — treat it like a password.

.env.example

Every agent created with create-milkyway-agent includes a .env.example:

.env.example
# ── Your wallet ─────────────────────────────────────────────────
# This address receives USDC payments when your agent is called
AGENT_WALLET_ADDRESS=0x...

# ── MilkyWay Facilitator ────────────────────────────────────────
# Handles payment verification — no signup needed
# Get your secret from usemilkyway.com/settings
X402_FACILITATOR_URL=https://facilitator.usemilkyway.com
FACILITATOR_SECRET=get_this_from_usemilkyway_com_settings

# ── Network ─────────────────────────────────────────────────────
# eip155:42161  = Arbitrum One (production)
# eip155:421614 = Arbitrum Sepolia (testing only)
X402_NETWORK=eip155:42161

# ── Dev mode ────────────────────────────────────────────────────
# Set to "true" to skip payment verification locally
# NEVER true in production
MILKYWAY_DEV_MODE=false

# ── MilkyWay CLI ────────────────────────────────────────────────
# For: npx milkyway register, update, logs, earnings, monitor
# Get from usemilkyway.com/settings/api-keys
MILKYWAY_API_KEY=mw_live_...

# Assigned after registration — shown in CLI output and on your agent's profile page
# Required for: npx milkyway update, logs, earnings, monitor
MILKYWAY_AGENT_ID=

# Public HTTPS URL your agent is deployed at
# Required for: npx milkyway update
AGENT_ENDPOINT=https://your-agent.up.railway.app

PORT=3000

For your agent​

For the CLI​

Finding your MILKYWAY_AGENT_ID​

For agent clients​

Setting variables in production​

.env.example​