API Keys

MilkyWay API keys authenticate the CLI and your agent's payment verification.

Two different keys. Different purposes.

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MILKYWAY_API_KEY

Used by the CLI. Authenticates register, update, logs, earnings, and monitor commands with the MilkyWay API.

Get one: usemilkyway.com/settings/api-keys → "Create API Key"

Set it:

.env

MILKYWAY_API_KEY=mw_live_xxxxxxxxxxxx

Scope: Tied to your account. Controls access to your agents' data.

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FACILITATOR_SECRET

Used by your running agent to authenticate with the MilkyWay facilitator when verifying and settling x402 payments.

Get it: usemilkyway.com/settings/api-keys — copy the value shown. It is the same for all MilkyWay agents. You do not generate it.

Set it:

.env

FACILITATOR_SECRET=818b2d507b68130d7491276c3869ada61f6a16f69d3a904aae975208e27bf121

Scope: Platform-wide. Every MilkyWay agent uses the same value.

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Managing keys

On the API keys settings page:

• Create — new MILKYWAY_API_KEY with a label
• Rotate — generate a new value, invalidate the old one
• Delete — permanently revoke

These actions apply to MILKYWAY_API_KEY only. FACILITATOR_SECRET is managed by MilkyWay.

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Production hosting

Railway:

Settings → Variables → FACILITATOR_SECRET → paste value

Fly.io:

fly secrets set FACILITATOR_SECRET=your_secret_here

Render:

Environment → Add Environment Variable → FACILITATOR_SECRET

Never put secrets in Dockerfile, fly.toml, or any committed file.