How to Connect Claude Duet to Sequenzy
Claude Duet is Anthropic's proactive agent, released as a research preview on October 21, 2026. It carries over the memory, skills, and connectors from your Claude account, which means connecting Sequenzy in Claude once gives Duet access to campaigns, sequences, subscribers, segments, templates, replies, and analytics.
This guide takes about ten minutes.
What You Need
- Access to Duet: a Pro or Max plan, a Claude account in the US, and an invitation from the waitlist
- A Sequenzy account
- Claude on the web, desktop, or mobile to add the connector, and the Duet app on iOS, Android, or claude.ai
Duet is not available on Team or Enterprise plans yet.
Which Sequenzy URL to Use
https://api.sequenzy.com/v1/mcpThis is Sequenzy's hosted MCP server, the one Claude uses on every platform. Duet works from Anthropic's cloud and cannot reach programs on your computer, so the local npx @sequenzy/mcp package does not work with it.
Step 1: Add Sequenzy as a Custom Connector in Claude
- In Claude, open Settings > Connectors.
- Choose Add custom connector.
- Name it
Sequenzy, paste the URL above, and confirm.
Anthropic sometimes renames these menus. If the labels differ, look for connectors under Settings or Customize.
Step 2: Sign In and Choose a Preset
Claude opens the Sequenzy sign-in page. Sign in, pick a permission preset, and select Allow.
| Preset | What Duet can do |
|---|---|
| Safer agent access | Inspect data, draft content, define lists and tags, tag contacts. No live delivery or deletes. This is the default |
| AI drafting | Also add and remove contacts in lists. No live delivery |
| Marketing sender | Manage and send campaigns and live sequences |
| Full access | Everything, including sending, settings, and deletes |
Keep Safer agent access to start. Duet asks before sending a message, and this preset adds a second check: Sequenzy itself refuses live sends from the connection. Your workspace role still applies, so a viewer stays read-only whatever preset you pick.
If you want a read-only first week, open Account Settings > API Keys in Sequenzy after connecting, find the key named Claude Remote MCP, and switch it to Read-only. You can widen it later on the same key without reconnecting.
Step 3: Test in a Claude Chat
Before involving Duet, check the connector in a normal Claude chat. Start a new chat, enable Sequenzy in the tools menu, and ask:
Using the Sequenzy connector, which workspace are you connected to? List
the active sequences with their trigger and the last three campaigns with
send date and status. Don't change anything.If it reports the wrong workspace, ask it to list your Sequenzy workspaces and switch.
Step 4: Confirm Duet Sees Sequenzy
Open Duet and send the same request. If Duet answers with your campaigns, it is using the connector.
If Duet says it has no Sequenzy connector, check that the connector is enabled in Claude, then ask Duet which connectors it can use. Anthropic documents that Duet carries over your Claude connectors but has not published notes on custom connectors in Duet specifically, and features can change during the research preview.
Step 5: Tell Duet What Belongs in the Brief
Anthropic says you can tell Duet what you want to hear about and how often. Give it a short, specific list:
For email, use the Sequenzy connector and only bring me:
- Subscriber replies in the Sequenzy inbox that are questions, bugs, or
cancellation risks, with a draft answer for questions
- Any send whose bounce or complaint rate is double its 4-week average
- Campaigns scheduled in the next 24 hours, with audience size
Put at most three email items in the morning brief. Read only unless I ask.Duet's background checks count toward your Claude usage limits, so a short list is cheaper at every check than "watch everything".
Step 6: Add a Weekly Review
For recurring work, ask once:
Every Friday afternoon, review the week in Sequenzy: sends, conversions,
unsubscribes, complaints, and sequence completions. Compare with the
previous four weeks and send me a short summary with one recommendation.
Read only.Duet tracks ongoing work in its Tasks tab, where you can see what it is doing and which tasks need your input.
Troubleshooting
Sign-in loops back to Claude without connecting
Finish the Sequenzy sign-in in the same browser as Claude and allow pop-ups. If the connector still shows as disconnected, remove it and add it again.
Tools return permission errors
The error names the missing Sequenzy permission. Open Account Settings > API Keys, edit the Claude Remote MCP key, and add the permission or switch preset. Then ask Duet to retry; the key value does not change.
Duet uses its browser instead of the connector
Anthropic says Duet uses its own browser for sites without a connector. Ask it to "use the Sequenzy connector". Connector calls are faster, and you cannot watch Duet's browser to check what it did.
A reply arrived but Duet did not mention it
Duet checks every few hours, so the reply may arrive before the next check. If it still does not appear, check that your instruction covers that sequence or campaign.
Disconnecting
Remove the connector in Claude under Settings > Connectors, then revoke its key in Sequenzy under Account Settings > API Keys, where remote connections appear as personal keys named Claude Remote MCP.
FAQ
Which URL do I use for Duet?
https://api.sequenzy.com/v1/mcp.
Is Sequenzy in Claude's connector directory?
Not yet. Add it as a custom connector.
Does Duet see connectors I add in Claude?
Anthropic says Duet carries over your Claude connectors. Ask Duet to confirm after you add Sequenzy.
Will it send without asking?
Duet asks before sending, and the default Sequenzy preset cannot send live email at all.
Can it react to replies immediately?
No. It finds them at its next check-in.
Next Steps
- See how to use Claude Duet for email marketing for workflows.
- Compare the 11 best email marketing tools for Claude Duet.
- Read more about MCP for email marketing.