Open source alternative to Superhuman, Shortwave, HEY and Spark
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Manage your email with a self-hosted inbox on Cloudflare Workers, backed by an AI agent that drafts replies and searches conversations.
If you already use Cloudflare for domains or hosting, Agentic Inbox adds a working email client with AI drafting to your existing infrastructure. The setup path (Wrangler and the Cloudflare dashboard) will be familiar, and your email data stays in Durable Objects under your account.
Skip if you need per-mailbox access control for multiple users, or if you are not already running Cloudflare infrastructure and do not want to start.
Replaces AI email clients like Superhuman or Shortwave for teams already in the Cloudflare ecosystem. The AI agent auto-drafts replies and lets you manage email through a modern web interface at no additional per-seat software cost.
Skip if your team needs a mobile app, calendar integration, or a managed support tier. Agentic Inbox is a developer-deployed tool with no mobile client documented in the README.
The MCP server at /mcp lets external AI tools query any mailbox by passing a mailboxId parameter. This makes Agentic Inbox a practical integration point for agents that need to read, search, or send email as part of a larger automated workflow.
Skip if you need per-tool or per-agent mailbox authorization. The Cloudflare Access policy is the single trust boundary; all authorized users and tools can access all mailboxes.
AI-enhanced email clients have become a crowded SaaS category. Superhuman, Shortwave, HEY, and Spark each offer intelligent inbox features, but every one of them requires handing your email over to their servers. There is no self-hosting path, no data portability guarantee beyond a GDPR export, and no protection if their pricing changes or the service shuts down.
For developers and teams that handle sensitive communications, running email through a third-party SaaS is a real risk. The inbox is one of the most data-dense places in any organization: it holds contracts, credentials, client conversations, and internal decisions. Storing that on a commercial service you do not control is a tradeoff many teams accept only because no self-hosted alternative with AI capabilities previously existed.
Sends and receives email via Cloudflare Email Routing. Includes a rich text composer with reply/forward threading, folder organization, search across conversations, and R2 attachment storage. All email stays in Cloudflare infrastructure under your account.
Each mailbox runs in its own Cloudflare Durable Object with a dedicated SQLite database, keeping storage scoped and isolated by design. One mailbox cannot read another's data. Attachments go to R2, keeping binary storage separate from the relational database.
A side panel runs an AI agent built on the Cloudflare Agents SDK and Workers AI (moonshotai/kimi-k2.5 model). It provides nine tools: reading the inbox, searching conversations, drafting replies, and sending on confirmation. All operations require explicit user approval before sending.
When a new email arrives, the AI agent reads it automatically and generates a draft reply. The draft waits for your review; the agent never sends without explicit confirmation. Custom system prompts per mailbox let you control the agent's writing tone and behavior.
Ships with an MCP server at /mcp so external AI tools (Claude Code, Cursor, and others) can operate on any mailbox by passing a mailboxId parameter. Authorization is governed by the Cloudflare Access policy, which is the single trust boundary for all mailbox access.
Superhuman is a proprietary AI email client with no self-hosting option. Agentic Inbox is an Apache-2.0 alternative that runs on your own Cloudflare Workers infrastructure.
| Feature | Agentic Inbox | Superhuman |
|---|---|---|
| License | Apache-2.0 | Proprietary |
| Self-hosting | Yes (Cloudflare Workers) | No |
| Email storage | Your Cloudflare account | Superhuman's infrastructure |
| AI drafting | Yes, with confirmation gate | Yes |
| Pricing | Cloudflare usage rates | Paid monthly subscription |
Agentic Inbox is the better choice when email data sovereignty matters: it keeps your inbox in infrastructure you control, not on a third-party's servers. Superhuman is the better pick for teams that need a polished mobile experience, Gmail and Outlook sync, or an enterprise support tier with no infrastructure to manage.
Shortwave is a proprietary AI email client with no self-hosting option, designed for Gmail users. Agentic Inbox brings AI drafting to any custom domain on Cloudflare with full data ownership.
| Feature | Agentic Inbox | Shortwave |
|---|---|---|
| License | Apache-2.0 | Proprietary |
| Self-hosting | Yes | No |
| Email backend | Cloudflare Email Routing | Gmail |
| AI features | 9-tool agent panel, auto-draft | AI summarization, triage |
| Pricing | Cloudflare usage rates | Paid monthly subscription |
Agentic Inbox is the better choice for teams not on Gmail and for those who require their email to stay on their own infrastructure. Shortwave is the better choice if you are committed to Gmail and want a managed product with no deployment overhead.
HEY is a proprietary opinionated email service with custom domains and no self-hosting option. Agentic Inbox takes the opposite approach: open source, self-hosted on Cloudflare, with an AI agent built in.
Agentic Inbox wins on data ownership and AI integration. HEY's opinionated inbox model offers a polished managed experience that Agentic Inbox does not replicate. HEY suits users who want to buy a well-designed inbox experience; Agentic Inbox suits developers who want to own their email stack.
Self-hosting deploys to Cloudflare Workers; clone the repo, install dependencies, and run the deploy script.
```bash
git clone https://github.com/cloudflare/agentic-inbox
cd agentic-inbox
npm install
npm run deploy
```The software is Apache-2.0 licensed and free to deploy. You pay Cloudflare's standard rates for Workers, Durable Objects, R2, and Email Routing, all of which have free tiers for low-volume use. There is no per-seat fee for the software itself.
It works with any domain managed on Cloudflare. You set the domain at deployment time via the DOMAINS variable, configure Email Routing to forward inbound email to the Worker, and create mailboxes for any address on that domain. Domains not on Cloudflare require adding or transferring DNS to Cloudflare first.
No. The agent auto-drafts a reply when new email arrives, but it holds that draft for explicit confirmation before sending. All outbound sending requires your approval. You can also customize the agent's tone and behavior with per-mailbox system prompts.
The agent runs on Cloudflare Workers AI using the moonshotai/kimi-k2.5 model. Workers AI runs on Cloudflare's own network; no third-party AI API key is required beyond what Cloudflare provisions automatically during deployment.
Yes, with a caveat: any user who passes the Cloudflare Access policy can access all mailboxes. There is no per-mailbox access control; the Access policy is the single trust boundary. For small teams where everyone should see everything, this works well. For teams that need per-user mailbox isolation, this is a current architectural limitation noted explicitly in the README.
#2 in the Superhuman guide
Fast keyboard triage with chat, tasks, and agents attached
#3 in the Superhuman guide
Fast desktop drop-in with a unified inbox
#4 in the Superhuman guide
Proven, extensible desktop email client
#5 in the Superhuman guide
Keyboard-first terminal triage
Run agentic-inbox on your own server
Self-host agentic-inbox on a Hostinger VPS.
Deploy on HostingerFeatured
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