One command
Add Mailgun to any Ashlr Stack project with a single command. Stack runs the auth flow, verifies the credential, and writes every secret slot into Phantom.
stack add mailgun
Or describe what you're building and let Claude pick it up via stack recommend:
stack recommend "transactional email for my app"Auth flow
Paste a long-lived API key once. Stack verifies it against the provider's API before writing to Phantom.
How-to: Paste an API key from https://app.mailgun.com/settings/api_security.
Secret slots
stack add mailgun writes these 1 secret
slot into your Phantom vault:
MAILGUN_API_KEY
The values never leave Phantom in plaintext. Your .env file references slot
names, and stack exec -- <cmd> swaps them in at process-spawn time via
Phantom's local proxy.
Related providers in Email
- Resend — Transactional + React Email. API key stored in Phantom.
- SendGrid — High-volume transactional mail. API key verified against /v3/scopes on paste.
- Postmark — Deliverability-focused transactional. Account token verified against /servers on paste.
FAQ
Do I need a Mailgun account to use it with Stack?
Yes — Stack provisions Mailgun on your behalf, but it authenticates as you. Paste a long-lived API key once. Stack verifies it against the provider's API before writing to Phantom. If you don't have a credential yet, create one at https://app.mailgun.com and paste it once.
Where does Stack store my Mailgun credentials?
In Phantom Secrets, an E2E-encrypted local vault. Stack writes the secret slot names (MAILGUN_API_KEY) into .stack.toml — the actual values live only in Phantom and never touch disk in plaintext.
Can I rotate or revoke this integration later?
Yes. Run `stack remove mailgun` to pull the Mailgun service back out (Phantom secrets deleted, MCP entry removed, .stack.toml cleaned up). Rotate the underlying Mailgun credentials in their dashboard — https://app.mailgun.com — and Stack's next `doctor --fix` will pick up the new values.