Deploy Inbox Zero | Open-Source AI Email Assistant for Gmail and Outlook

Deploy and Host Inbox Zero on Railway

Inbox Zero is the open-source AI email assistant for Gmail and Outlook. You describe how you want your email handled in plain English: label and archive newsletters, draft replies in your voice, flag cold outreach, follow up on threads nobody answered. Inbox Zero applies those rules to new mail as it arrives. It also has one-click bulk unsubscribe, a reply tracker, email digests, meeting briefs and an assistant chat over your inbox. This template runs the full self-hosted version with every premium feature unlocked, using your own AI provider key, so your mail never passes through someone else's SaaS.

About Hosting Inbox Zero

The stack is four services: Inbox Zero, Redis-HTTP, Redis and Postgres.

• Inbox Zero is the Next.js web app and API on the public domain. It receives Gmail push notifications and Outlook webhooks, runs your rules through the LLM and acts on your mailbox.
• Scheduled jobs built in. Upstream runs a separate cron container that calls the app's job endpoints. Here the same loops run inside the Inbox Zero service and start once the app is healthy: scheduled actions and snoozes every 15 minutes, automation jobs, digests, meeting briefs and follow-up reminders, and Gmail/Outlook watch renewal every 6 hours. That keeps real-time notifications from expiring.
• Redis-HTTP is serverless-redis-http, the Upstash-compatible REST proxy that upstream's compose file also uses. Inbox Zero talks to Redis through it for caching, rate limits and locks.
• Redis backs that proxy and the live inbox updates in the UI.
• Postgres holds users, connected accounts, rules, history and encrypted OAuth tokens.
• Safe first boot. On a fresh deploy Postgres is often still starting. Upstream's start script skips failed migrations and boots anyway, which leaves an app without tables. This template retries the migrations until they succeed, and only then starts the server.
• Locked to you. Only the addresses in AUTH_ALLOWED_EMAILS can sign up, so nobody else can use your instance or your AI key.

Common Use Cases

• An AI assistant that triages, labels, archives and pre-drafts replies for a busy founder or sales inbox
• Cleaning up years of newsletters and promotions with bulk unsubscribe and archive, without granting a third-party SaaS access to your mailbox
• A team or company deployment where email content and AI calls must stay on infrastructure you control, with your own LLM provider or zero-data-retention keys

Dependencies for Inbox Zero Hosting

• Postgres 17 (included, private network only)
• Redis 8 and the serverless-redis-http proxy (included, private network only)
• A Google Cloud OAuth client (for Gmail) and/or a Microsoft Entra app registration (for Outlook)
• An API key from an LLM provider: Anthropic, OpenAI, Google, OpenRouter, Groq, Bedrock and more

Deployment Dependencies

• Inbox Zero self-hosting docs
• Google OAuth setup and Google Pub/Sub setup
• Microsoft OAuth setup
• LLM providers and model settings
• Inbox Zero on GitHub
• Template source on GitHub

Implementation Details

Inbox Zero lives at the Inbox Zero service's Railway domain (https://.up.railway.app, written YOUR_DOMAIN below). You can deploy before you have the OAuth credentials: put placeholders in GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET and GOOGLE_PUBSUB_TOPIC_NAME, read the domain off the service once it is up, then come back and fill them in. The first boot runs the database migrations and takes 2–3 minutes.

Gmail (Google OAuth)

1. In Google Cloud Console, create or pick a project and open APIs & Services → OAuth consent screen. Choose Internal for Google Workspace, or External for personal Gmail. With External, add your own address under Audience → Test users.
2. Under Data Access → Add or remove scopes, add userinfo.profile, userinfo.email, https://www.googleapis.com/auth/gmail.modify and https://www.googleapis.com/auth/gmail.settings.basic.
3. Enable the Gmail API.
4. Go to Credentials → Create credentials → OAuth client ID → Web application. Set Authorized JavaScript origins to https://YOUR_DOMAIN, and Authorized redirect URIs to:
   • https://YOUR_DOMAIN/api/auth/callback/google
   • https://YOUR_DOMAIN/api/google/linking/callback
   • https://YOUR_DOMAIN/api/google/calendar/callback (optional, calendar)
   • https://YOUR_DOMAIN/api/google/drive/callback (optional, Drive)
5. Copy the client ID and secret into GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET on the Inbox Zero service.
6. For real-time email processing, create a Pub/Sub topic (for example inbox-zero-emails). Under its Permissions, grant gmail-api-push@system.gserviceaccount.com the Pub/Sub Publisher role.
7. On that topic, create a Push subscription with the endpoint https://YOUR_DOMAIN/api/google/webhook?token=TOKEN. Use the GOOGLE_PUBSUB_VERIFICATION_TOKEN value from the service's Variables tab as TOKEN.
8. Set GOOGLE_PUBSUB_TOPIC_NAME to the full name, projects//topics/inbox-zero-emails, and let the service redeploy.

Outlook (Microsoft OAuth, optional)

1. In the Azure portal, open Microsoft Entra ID → App registrations → New registration. Pick multitenant for any Microsoft account, or single tenant for your organization only. Add a Web redirect URI: https://YOUR_DOMAIN/api/auth/callback/microsoft.
2. Under Authentication, add https://YOUR_DOMAIN/api/outlook/linking/callback. Optionally add https://YOUR_DOMAIN/api/outlook/calendar/callback and https://YOUR_DOMAIN/api/outlook/drive/callback.
3. Under API permissions → Microsoft Graph → Delegated, add openid, profile, email, User.Read, offline_access, Mail.ReadWrite, Mail.Send, MailboxSettings.ReadWrite, Calendars.Read, Calendars.ReadWrite and Files.ReadWrite.
4. Under Certificates & secrets → New client secret, create a secret. Set MICROSOFT_CLIENT_ID (Application ID) and MICROSOFT_CLIENT_SECRET (the secret's Value). For single tenant, also set MICROSOFT_TENANT_ID.
5. Outlook only? Set GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET and GOOGLE_PUBSUB_TOPIC_NAME to skipped.

AI provider. DEFAULT_LLMS and ECONOMY_LLMS take provider:model entries, and the default is Anthropic. For OpenAI, use for example openai:gpt-6-luna; the same pattern works for google:, openrouter:, groq: and bedrock:. Put the matching key in LLM_API_KEY. A ChatGPT or Claude subscription does not include API access; the key needs billing credits on the provider's platform.

Sign in at https://YOUR_DOMAIN with Google or Microsoft, using an address listed in AUTH_ALLOWED_EMAILS. To add teammates, extend that list, or set AUTH_ALLOWED_EMAIL_DOMAINS=yourcompany.com instead.

Memory. Expect about 1.1 GB at idle on Railway: about 0.9 GB for Inbox Zero, 120 MB each for Redis-HTTP and Postgres, and under 10 MB for Redis. Inbox Zero alone is over the Trial plan's limit, so deploy on Hobby or above.

Custom domain. Add it in the Inbox Zero service's Settings → Networking. Set NEXT_PUBLIC_BASE_URL to https://your.domain, then update the OAuth redirect URIs and the Pub/Sub push endpoint to the new domain.

Never change EMAIL_ENCRYPT_SECRET or EMAIL_ENCRYPT_SALT after the first sign-in. They encrypt the stored OAuth tokens, so changing them disconnects every mailbox.

Backups. Everything lives in Postgres, so turn on Railway's volume backups for the Postgres volume.

Why Deploy Inbox Zero on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying Inbox Zero on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.