Connect Slack to Claude and ChatGPT
Yes — Claude and ChatGPT can both read, search and reply to your Slack messages through Mailopoly, which is listed in the Claude Connectors Directory and is an approved app in the ChatGPT app directory. Connect Slack to Mailopoly through Slack's own sign-in, add Mailopoly in Claude or ChatGPT, and ask. The whole setup takes about a minute. Business channels are a Pro or Business plan feature, and your Slack workspace admin may need to approve the Mailopoly app.
Before you start
- A Mailopoly account — 7-day free trial, no credit card.
- A Mailopoly Pro or Business plan — messaging channels aren't on the email-only plans.
- Business channels are a Pro or Business plan feature, and your Slack workspace admin may need to approve the Mailopoly app.
- Claude on any plan, including Free, or ChatGPT with apps enabled.
Connect Slack to Claude or ChatGPT in three steps
1Connect Slack to Mailopoly
- Start a Mailopoly account at mailopoly.com/sign-up on a Pro or Business plan.
- In the Mailopoly web app open Profile → Apps and choose Connect Slack.
- Sign in to Slack and choose the workspace. If your workspace restricts apps, an admin approves Mailopoly from the request Slack sends them.
- Pick the channels and direct messages you want in your inbox. They arrive alongside your email, filtered by Cleanbox and briefed in My Day.
Already signed in? Open Profile → Apps in the Mailopoly web app ↗
2Add Mailopoly to Claude or ChatGPT
This part is the same whatever you connected in step 1. Mailopoly is listed in both directories, so it's a search and a tap — no endpoint URL to paste.
Claude
- Open Settings → Connectors on claude.ai or in the Claude app — or choose Add connectors from the + menu in any chat.
- Search the directory for Mailopoly and choose Connect.
- Sign in with your Mailopoly account when prompted, then choose what Claude is allowed to do. Reading, making changes and sending are separate permissions.
- Back in the chat, make sure the Mailopoly connector is switched on, then ask.
One listing covers Claude.ai, Claude Desktop, Claude mobile, Claude Code and Cowork, and it works on every Claude plan, including Free. In Claude Code you can also run claude mcp add --transport http mailopoly https://fastapi.prod.aws.mailopoly.com/mcp-server/ and then /mcp to sign in.
ChatGPT
- Open the Apps directory in ChatGPT — from the + menu in any chat, or Settings → Apps & Connectors.
- Search for Mailopoly and choose Connect.
- Sign in with your Mailopoly account when prompted, then choose what ChatGPT is allowed to do. Reading, making changes and sending are separate permissions.
- In any chat, type
@Mailopolyand ask.
Mailopoly is an approved app in the ChatGPT app directory, so there's no developer mode and no endpoint URL to paste. Once connected it's available in every ChatGPT conversation on the web and in the mobile apps.
Using something else? Claude Code, Cowork, Codex and any client that supports remote MCP servers connect the same way — the Mailopoly MCP page has the endpoint and per-client steps.
3Ask about your Slack
Whatever you've connected to Mailopoly is what your assistant can reach. Some things people ask on day one:
- What happened in #launch on Slack this week?
- Did anyone on Slack ask me a question I haven't answered?
- Reply in the Slack thread with Dana — say the deck is ready.
What Claude and ChatGPT can do with Slack through Mailopoly
- Read and search your Slack conversations alongside your email, in one question.
- Catch up on a week in a channel. "What happened on Slack this week?" comes back as a summary, not a scroll.
- Find the message you half remember — by person, date or topic, across Slack and every inbox you've connected.
- Reply back out through Slack, from the account or handle the message came in on. Sending is a separate permission and a confirm-first action.
- One feed, one task list. Slack messages that need action land in My Day next to the emails that do.
- Unified with your email. Ask about a customer and get their Slack thread and their emails in the same answer.
Reading, making changes and sending are separate permissions you grant when you connect, and you can revoke an assistant at any time from Settings → Security in the Mailopoly app. More on the security page.
What goes wrong with Slack, and the fix
- Workspace admins may need to approve the app. Slack sends the request; nothing arrives until it's approved.
- Private channels only appear once you're a member and have chosen to include them.
- Replies go back out through Slack from your own Slack account, in the thread they belong to.
7-day free trial, no credit card. Connect Slack in about a minute.
Frequently asked questions
Other connect guides
Email providers
- Gmail
- Outlook
- Yahoo Mail
- iCloud Mail
- AOL Mail
- Comcast Email
- Zoho Mail
- Yandex Mail
- GMX
- Fastmail
- Any IMAP Mailbox
