What the Klaviyo MCP server actually is
Klaviyo shipped its MCP server in September 2025 and was one of the
first ESPs into Claude's connector directory, in January 2026. It is
first-party and hosted by Klaviyo at
mcp.klaviyo.com/mcp, you authenticate with your normal
Klaviyo login through OAuth, and there is no key to create for the
standard route. Since May 2026 it can also render interactive charts
inline in Claude, so a revenue question can come back as a dashboard
rather than a paragraph.
The tool surface is the largest of any ESP connector: over 200 tools across 18 categories, generated from the same API Klaviyo's own interface uses. By default clients get a core set of about 40 tools, which is the right amount; the full set is available when a setup needs catalogs, coupons or webhooks.
Role gate. The hosted server only authenticates users with an Owner, Admin or Manager role on the Klaviyo account. If Connect fails, check your role before anything else.
What it can do, area by area
| Area | Access | What it means for a marketer |
|---|---|---|
| Campaigns read and write | Read + create, clone, update | Pull past campaigns, create new ones, clone winners, assign templates, estimate recipients. Klaviyo's own guidance for agencies: treat the output as drafts a human QAs before anything is scheduled. |
| Templates read and write | Read + create + preview | Create real drag-and-drop templates, not just raw HTML, render them to check the result, and fire a preview send to yourself. |
| Lists & segments read and write | Full create and update | Create and edit segments and lists in a sentence, and see which flows a list or segment triggers before touching it. |
| Profiles read and write | Read + create, update, subscribe | Look up any customer's history, update attributes, manage subscriptions, run bulk imports and suppressions. |
| Reporting read only | Read | Campaign and flow reports, plus metric aggregates: revenue attributed per flow, campaign or segment over windows up to a year. The strongest single reason to connect. |
| Flows mostly read | Read + status change | List flows and read their structure, turn a flow live or back to draft. Editing the emails inside a flow is not on the surface; see the limits below. |
| Catalogs & images read and write | Read + bulk jobs, upload | Query products and variants, run bulk catalog jobs, upload images by URL for use in templates. |
Set it up in Claude, step by step
Check your Klaviyo role
You need Owner, Admin or Manager on the account. Everything else about the standard route is two clicks, so this is the only real prerequisite.
Connect from the directory
In Claude, open Settings, then Connectors, search for Klaviyo and click Connect. You sign in to Klaviyo and approve the permissions. No URL, no key, no config file.
Turn it on inside the chat
Start a new chat, click the plus button, open Connectors and toggle Klaviyo on. Connectors are per conversation, which keeps your research chats and your account-connected chats separate on purpose.
Verify with something read-only
List my Klaviyo segments with their sizes, and name my five most recent campaigns. Don't change anything.
Agencies and multi-account setups. The directory listing connects one account. For several client accounts, add the server as a custom connector once per account with https://mcp.klaviyo.com/mcp?company=account-name, and keep one Claude Project per client. Custom connectors require a paid Claude plan. There is also a local variant (uvx klaviyo-mcp-server@latest with a private API key) for config-file setups; the hosted route is where new capability lands first.
The first prompts worth running
Klaviyo's connector is at its best on revenue questions, because the metric-aggregate reporting can answer things the dashboard makes you assemble by hand.
Which flows and campaigns drove the most attributed revenue in the last 90 days? Show revenue per recipient, not just totals.
List my live flows and when each was last edited. Which ones have the weakest conversion per trigger, and what would you test first?
Draft a campaign for my VIP segment announcing [offer]: subject, preview text, body. Create it in Klaviyo with the template assigned, but do not schedule it.
What it will not do
- It will not build a flow. The only flow write is a status change (live, draft, manual). The emails inside a flow cannot be edited from chat, so flow work means drafting content with the agent and assembling in Klaviyo.
- Treat sending as not-yet. The tool list includes campaign send jobs, but Klaviyo's own agency guidance says end-to-end scheduling and sending is still rolling out through 2026, and to QA everything as a draft. That is the honest workflow today: create, review, and schedule in Klaviyo yourself.
- User-generated content carries a warning. Klaviyo flags tools that return customer-written data (events, profiles, reviews) as a prompt-injection risk and says to review each call. If that worries you, connect with the option that disables those tools, or stay read-only at first.
- The full tool set is heavy. 200+ tools weigh on a chat's context. The default core set of about 40 is enough for campaign work; only widen it when a job needs catalogs or coupons.
- It does not run on its own. No triggers, no background execution. The flows do that; the connector is for the conversation.
Where Plainpaper fits
Klaviyo's connector reads and writes the account, but the deciding happens somewhere else: which segment, which offer, which subject line, and who signed it off. On a Plainpaper board the agent pulls revenue data through Klaviyo's connector, drafts the campaign and its variants as cards, and creates nothing in Klaviyo until you approve. The Klaviyo and Shopify workflow guide runs that loop end to end for an ecommerce store.
Key takeaways
- Klaviyo's MCP server is first-party, hosted at mcp.klaviyo.com/mcp, and in Claude's connector directory: OAuth sign-in, no API key, free with any Klaviyo account.
- Over 200 tools in 18 categories, with a default core set of about 40. Campaigns, drag-and-drop templates, segments, profiles, catalogs and revenue reporting are all on the surface.
- Flow editing is the big gap: status changes only, no editing the emails inside a flow.
- Klaviyo's own guidance is to treat campaign output as drafts a human QAs; end-to-end send is still rolling out through 2026.
- You need an Owner, Admin or Manager role, and tools that return customer-written content carry Klaviyo's own prompt-injection warning.
Frequently asked questions
Is there an official Klaviyo MCP server?
Yes. Klaviyo built and hosts it, shipped it in September 2025, and listed it in Claude's connector directory in January 2026. There is also a local package for config-file setups, but the hosted server is the recommended route and the one that gets new capability first.
Do I need an API key?
Not for the standard route. The directory connector authenticates with your Klaviyo login over OAuth. A private API key is only needed for the local variant, which is a developer setup.
Can Claude send a Klaviyo campaign?
It can create one, clone one and assign its template. For sending, Klaviyo's agency guidance is explicit that end-to-end scheduling and sending is still rolling out during 2026 and that output should be QA'd as drafts. Create in chat, review, schedule in Klaviyo.
Can it build or edit flows?
No. It can list flows, read their structure and switch a flow between live and draft, and that is the ceiling. The emails inside a flow are not editable from chat, so the working pattern is: agent drafts the flow's emails, you assemble them in Klaviyo's flow builder.
What does it cost, and which plan do I need?
The server is free and available to every Klaviyo customer, including free accounts. The only Klaviyo-side gate is your role: Owner, Admin or Manager. On the Claude side, the directory connector is the standard route; only the multi-account custom-connector setup requires a paid Claude plan.
What is the prompt-injection warning about?
Some tools return content your customers wrote: event data, profile fields, reviews. Klaviyo warns that a malicious string in that data could try to steer the agent, and tells you to review each tool call. The connector can be added with those tools disabled, which is the sensible default for a first week.
Keep reading
- Klaviyo, Shopify and Claude workflow: the ecommerce campaign loop this connector powers.
- Best email template tools for Claude: Klaviyo next to Brevo, MailerLite and the other ESPs that clear the marketer bar.
- Post-purchase flow playbook: mine order patterns for the second-order sequence, exactly the data this connector reads.
- Welcome series playbook: the flow content the agent drafts before you assemble it in Klaviyo.
- Draft email campaigns in Plainpaper: email cards, A/B variants, and the ESP handoff.