Upstream

Upstream is an AI-powered email client built by Upstream Labs, Inc. and backed by Y Combinator. It connects to Gmail and uses agentic AI to sort incoming messages, pre-draft replies in the user's personal voice and tone, and surface smart follow-ups at the right time. The product is available as a web app and an iOS app, with a free-forever tier and paid plans for individuals and teams.

What It Is

Upstream sits on top of Gmail as a full inbox replacement rather than a plugin or add-on. Its core job is to reduce the cognitive load of email by doing three things automatically: organizing messages into focused "Splits," generating ready-to-send draft replies before you even open a thread, and scheduling follow-up reminders with pre-written drafts so nothing slips through the cracks. The product is positioned as "the first inbox designed for humans and agents," signaling that it is built to work alongside AI agents as well as human users.

How the Core Workflow Works

The Upstream workflow has three main stages:

• Triage: On arrival, messages are sorted into Splits (Primary, Needs Reply, VIP, Noise, etc.). Cold emails and newsletters are moved out of the way automatically. A "Needs Reply" view surfaces only the threads that require action.
• Draft: Upstream analyzes past sent emails to build a personalized voice-and-tone profile. When you open a message, an AI draft is already waiting. Drafts account for recipient history, thread context, and individual writing patterns.
• Follow-up: For threads where a reply was sent but no response came, Upstream assesses context to determine the right return time and pre-generates a follow-up draft.

Additional productivity features include keyboard shortcuts, a command palette (Command K), snooze, send-later, undo send, bulk triage for clearing backlogs, and multi-account support.

Team Collaboration Layer

Beyond individual productivity, Upstream includes a collaboration layer aimed at teams:

• Channels turn email threads into shared spaces where multiple team members can work together.
• Team Comments let colleagues have private discussions inside a thread without sending an external reply.
• Thread Sharing makes it easy to loop in teammates on any conversation.
• The free Core plan supports up to 5 team seats; paid plans remove the seat cap.

Integrations and Agent Support

Upstream connects to external tools to bring additional context into the inbox. The homepage highlights a native integration with Granola (a meeting notes tool) that automatically drafts follow-up emails after each meeting. The "For Agents" section indicates that AI agents can interact with the inbox directly, handling requests such as tracking receipts, booking meetings, or drafting personal notes. The product also surfaces context from calendar and knowledge-base apps.

Security and Privacy Posture

Upstream states CASA Tier 2 compliance, full encryption in transit and at rest, and a policy of never training AI models on user email data. Infrastructure is described as secure cloud with a claimed 99.9% uptime SLA.

Current Status

Upstream launched publicly on Product Hunt (the homepage displays a live Product Hunt banner). The company is incorporated as Upstream Labs, Inc. and lists Y Combinator as a backer. An iOS app is available on the App Store (app ID 6751403722). The pricing page shows an active "Save 20%" annual billing toggle, and the feature comparison table is live with three tiers: Core (free), Pro, and Max.