How to Build an AI Agent for Gmail and Slack

The workflow problem

Customer-facing teams monitor shared inboxes. support@, sales@, partnerships@, billing@. Each inbox receives a mix of urgent requests, routine questions, spam, and messages that should have gone somewhere else entirely. A billing question lands in the support inbox. A partnership proposal sits in the sales inbox for three days because the rep thought it was a marketing pitch. An urgent production issue reported by email does not get seen until someone checks the inbox during their morning triage routine, hours after the customer sent it.

The team’s actual work, collaboration, decisions, and responses, happens in Slack. But email and Slack are separate workflows. Someone has to open the inbox, read each email, decide who should handle it, copy the relevant content into Slack, wait for a response, then go back to Gmail to write the reply. This manual routing is tedious, error-prone, and slow. On a busy day, emails sit for hours because nobody wants to be the one doing inbox triage when they have other work to do.

Forwarding rules help for simple cases but break down quickly. You can forward all emails containing “billing” to a billing channel, but when a customer writes “I love your product but I have a billing question and also want to discuss expanding our contract,” a keyword filter does not know that this needs both the billing team and the account manager. The email gets routed to one place, the other party never sees it, and the customer gets a partial response.

Why an AI agent, not just automation

Email forwarding rules operate on surface-level signals: sender address, subject line keywords, recipient. They cannot read an email and understand its intent, urgency, or the expertise required to respond. An AI agent can.

The agent reads each incoming email and makes a nuanced routing decision. It understands that an email from a known enterprise customer reporting a data discrepancy in their dashboard is urgent, should go to the engineering support channel, and should also alert the account manager. It recognizes that an email asking about pricing for a 500-seat deployment is a high-value sales inquiry, not a support ticket. It identifies that a message written in frustrated language about repeated billing errors needs immediate human attention, not a templated response.

Beyond routing, the agent drafts contextual responses. Not generic templates with “Dear Valued Customer,” but responses that address the specific question asked, reference relevant documentation or knowledge base articles, and match the tone of the incoming email. The human reviewer refines and sends the draft rather than writing from scratch, cutting response time from thirty minutes to five. When the agent is uncertain about the right answer, it says so explicitly in the draft rather than guessing, ensuring the human reviewer adds genuine value rather than just approving boilerplate.

How it works with ACP

The Agentic Control Plane connects to Gmail via OAuth with scoped access to specific inboxes (typically shared team addresses, not personal accounts) and to Slack via a bot token with access to designated channels. The agent can read incoming emails, draft replies in Gmail, and post messages and threads in Slack channels.

When a new email arrives in a monitored inbox, the agent processes it through several stages. First, it classifies the email by type (support request, sales inquiry, partnership proposal, feedback, spam) and urgency (immediate, same-day, routine). Then it identifies the appropriate Slack channel based on the classification and any additional context like the sender’s company, existing conversation history, or mentioned products. Finally, it posts a structured summary to the channel and, when appropriate, drafts a response.

The Slack post is not a raw email forward. It is a structured card that includes the sender information, a one-line summary of the request, the full email content in a collapsible thread, suggested response actions, and the agent’s drafted reply if applicable. Team members can react to claim the email, discuss in the thread, and approve or edit the draft response directly from Slack.

Here is how the agent handles a multi-faceted customer email:

Incoming email to support@ from sarah.chen@acmecorp.com:

“Hi team, we’ve been using your API for three months and love it. However, we’re seeing intermittent 429 errors during our peak processing window (2-4 PM EST). We’re currently on the Growth plan doing about 50K requests/hour during peak. Two questions: (1) Is there a way to increase our rate limit without upgrading? (2) We’re also interested in the Enterprise plan pricing because we’re planning to scale to 200K req/hour by Q3.”

Agent posts to #customer-support:

“New inquiry from Acme Corp (Growth plan customer, 3 months) Urgency: Standard | Type: Technical support + Sales inquiry

Sarah Chen is hitting rate limits (429s) at 50K req/hr during peak hours. Two requests:

1. Rate limit increase on current Growth plan
2. Enterprise plan pricing for 200K req/hr by Q3

Draft response: [expand thread to see] Action needed: Technical answer from support + pricing handoff to sales

I’ve also posted this to #sales with the Enterprise pricing request.”

Agent posts to #sales:

“Expansion opportunity - Acme Corp: Current Growth customer looking to 4x their usage to 200K req/hr by Q3. Requesting Enterprise pricing. Technical context in #customer-support thread. Sarah Chen is the contact.”

In the #customer-support thread, the agent provides a draft:

“Draft reply: ‘Hi Sarah, thanks for the feedback and for being an API customer! For your rate limit question: Growth plans support burst capacity up to 75K req/hr. I can enable burst mode on your account immediately, which should resolve the 429 errors during your peak window. For Enterprise pricing at 200K req/hr, I’m looping in [account manager] who can walk you through options and volume pricing. They’ll reach out within one business day. Let me know if the burst mode doesn’t resolve the immediate issue.’”

Support engineer reviews the draft, adjusts the burst capacity details, and sends from Gmail through the agent.

The agent maintains a thread in Slack for each email conversation, so follow-up replies from the customer appear in the same thread, preserving context across multiple exchanges.

Governance and security

Email contains some of the most sensitive data in any organization: customer communications, contracts, personal information, and confidential business discussions. The agent’s access must be tightly controlled.

Gmail OAuth scopes are restricted to the minimum necessary. The agent uses gmail.readonly to read incoming emails and gmail.compose to draft responses in the shared inbox. It does not have gmail.modify (cannot move, delete, or label emails) or access to sent mail history beyond conversations it is actively managing. Crucially, the agent is connected to shared team inboxes, not individual employee email accounts. Personal email remains completely inaccessible.

Slack bot permissions are scoped to specific channels. The agent can post to designated routing channels (#support, #sales, #billing) but cannot access private channels, DMs, or channels it has not been added to. It can read messages in threads it created to maintain conversation context but does not monitor general Slack activity.

Sensitive content handling is configurable. The agent can be configured to redact credit card numbers, social security numbers, and other PII patterns before posting to Slack. Emails flagged as containing attachments with certain file types (such as contracts or financial documents) can be routed differently, with only metadata posted to Slack and the full content accessible only through Gmail.

The ACP audit trail records every email processed, its classification, routing decision, and any draft response generated. This audit trail enables teams to review the agent’s routing accuracy, identify emails that were misclassified, and demonstrate response time improvements. For organizations with email retention policies, the audit log complements Gmail’s native retention without duplicating email content.

Response drafts are never sent automatically. The agent always requires a human to review, edit if necessary, and explicitly approve before any reply leaves Gmail. This human-in-the-loop requirement is enforced at the platform level and cannot be bypassed by agent configuration.

Example use cases

• Multi-channel customer routing: A customer email that touches support, billing, and sales topics is simultaneously posted to all relevant Slack channels with context specific to each team, ensuring comprehensive handling without the customer needing to send separate emails.

• SLA monitoring: The agent tracks response times for each email and escalates in Slack when an inquiry approaches the SLA deadline without a response, posting to a manager’s channel with the aging email details.

• After-hours triage: Emails arriving outside business hours are classified by urgency. Truly urgent issues trigger Slack notifications to on-call staff. Routine inquiries queue for morning triage with draft responses already prepared.

• Customer context enrichment: When routing an email, the agent includes context from previous conversations in the same Slack thread, showing the customer’s history, plan type, and open tickets, so the responder has full context without switching to a CRM.

• Response quality analytics: The agent tracks which draft responses are sent as-is versus heavily edited, providing insights into which types of inquiries it handles well and where human expertise is most needed.

Getting started

Set up your Gmail-to-Slack routing agent in three steps:

1. Sign up at cloud.agenticcontrolplane.com and create your workspace.
2. Connect your tools by authorizing the shared Gmail inbox and your Slack workspace on the Data Sources page. Select which inbox to monitor and which Slack channels should receive different types of emails.
3. Describe your agent: “Monitor the support inbox. Classify each email by type and urgency. Route to the appropriate Slack channel with a summary and draft response. Escalate urgent emails immediately. Track response times and alert when SLAs are at risk.”

Your first emails will be routed with intelligent summaries and draft responses within minutes, with every action logged in the audit trail.