Customer.io MCP

CALL ANY TOOL

List and inspect campaigns, track events, query customer profiles, and send transactional messages.

customerio_campaigns_list

List campaigns

List all Customer.io campaigns with status, type, and send count.

Parameters

Name

Type

Required

Description

type

string

Optional

Campaign type: email, push, sms, webhook

limit

integer

Optional

Max campaigns to return

customerio_campaign_get

Get campaign

customerio_customers_search

Search customers

customerio_customer_get

Get customer

customerio_event_track

Track event

customerio_transactional_send

Send transactional

Build your Agent

Drop the toolkit in, point it at the user, and your marketing automation agent can use Customer.io MCP from the first run.

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import { ScalekitClient } from "@scalekit-sdk/node";
import { DynamicStructuredTool } from "@langchain/core/tools";
import { createReactAgent } from "@langchain/langgraph/prebuilt";
import { z } from "zod";

const sk = new ScalekitClient(envUrl, clientId, clientSecret);

const { tools } = await sk.tools.listScopedTools("user_123", {
  filter: { connectionNames: ["customeriomcp"], toolNames: ["customerio_campaigns_list", "customerio_campaign_get", "customerio_customers_search"] },
  pageSize: 100,
});

const lcTools = tools.map((t) => new DynamicStructuredTool({
  name: t.tool.definition.name,
  description: t.tool.definition.description,
  schema: z.object({}).passthrough(),
  func: async (args) => {
    const { data } = await sk.tools.executeTool({
      toolName: t.tool.definition.name,
      identifier: "user_123",
      params: args,
    });
    return JSON.stringify(data);
  },
}));

const agent = createReactAgent({ llm, tools: lcTools });

Copied

import { ScalekitClient } from "@scalekit-sdk/node";
import OpenAI from "openai";

const sk = new ScalekitClient(envUrl, clientId, clientSecret);
const openai = new OpenAI();

const { tools } = await sk.tools.listScopedTools("user_123", {
  filter: { connectionNames: ["customeriomcp"], toolNames: ["customerio_campaigns_list", "customerio_campaign_get", "customerio_customers_search"] },
  pageSize: 100,
});

const llmTools = tools.map((t) => ({
  type: "function",
  function: {
    name: t.tool.definition.name,
    description: t.tool.definition.description,
    parameters: t.tool.definition.input_schema,
  },
}));

const resp = await openai.responses.create({
  model: "gpt-4o", input: prompt, tools: llmTools,
});

import { ScalekitClient } from "@scalekit-sdk/node";
import Anthropic from "@anthropic-ai/sdk";

const sk = new ScalekitClient(envUrl, clientId, clientSecret);
const anthropic = new Anthropic();

const { tools } = await sk.tools.listScopedTools("user_123", {
  filter: { connectionNames: ["customeriomcp"], toolNames: ["customerio_campaigns_list", "customerio_campaign_get", "customerio_customers_search"] },
  pageSize: 100,
});

const llmTools = tools.map((t) => ({
  name: t.tool.definition.name,
  description: t.tool.definition.description,
  input_schema: t.tool.definition.input_schema,
}));

const msg = await anthropic.messages.create({
  model: "claude-sonnet-4-6", max_tokens: 1024,
  tools: llmTools,
  messages: [{ role: "user", content: prompt }],
});

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import { Agent } from "@google/adk/agents";
import {
  MCPToolset, StreamableHTTPConnectionParams,
} from "@google/adk/tools/mcp";

const toolset = new MCPToolset({
  connectionParams: new StreamableHTTPConnectionParams({
    url: "https://mcp.scalekit.com/customeriomcp",
    headers: { Authorization: `Bearer ${userScopedToken}` },
  }),
});

const agent = new Agent({
  name: "agent", model: "gemini-2.0-flash",
  tools: await toolset.getTools(),
});

Try these prompts

Paste any prompt into your agent to start using Customer.io MCP.

Search & recall

Copy the prompt

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List all active email campaigns.

Copy the prompt

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Which campaigns are in draft status?

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Find customers in segment [segment name].

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Get metrics for campaign [campaign name].

Action & sends

Copy the prompt

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Track event [event name] for customer [id].

Copy the prompt

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Send transactional [template id] to [email].

Copy the prompt

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List all customers with attribute [attr] = [value].

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Pull open and click rates for [campaign].

Reporting & optimization

Copy the prompt

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Which campaigns had the lowest open rates this week?

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Compare send volume by channel this month.

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List customers who triggered [event] but did not convert.

Copy the prompt

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Show unsubscribe rate by campaign type.

SEE HOW AUTH WORKS

Users authorize Customer.io MCP once. Their credentials stay vaulted, every call is checked, and every action is logged.

1

Authorize

Your user connects

Customer.io MCP

once. We tie it to their identity and the meetings they approved — no shared bot account, no org-wide access

Who:

user ‘A’

when:

Once per user

access:

Limited to user

2

Store

Their

Customer.io MCP

token lives in a vault scoped to them. User A's meetings are never reachable by an agent acting for user B, even on the same connection

vault:

encrypted

scope:

per-user

tokens:

auto-refreshed

3

Resolve

When your agent calls a

Customer.io MCP

tool, we fetch the right token server-side. It never touches your agent, never appears in the LLM context, never shows up in your logs

speed:

~40ms

check:

before every call

seen by:

nobody

4

Audit

Every

Customer.io MCP

tool call is logged — who triggered it, which meeting was fetched, what came back. 90 days of history, tied to the user who authorized it

history:

90 days

export:

SIEM-ready

logged:

every call

Test other agents

Same per-user auth pattern across other marketing automation agents and MCP connectors. Working code, live demos, fork what fits.

SALES

Outbound prospecting agent

Build targeted prospect lists with Apollo, enrich with firmographic data, and draft personalised outreach. Runs on a schedule.

Apollo

View agent

GTM

HubSpot to Slack updates agent

Watch HubSpot deal stage changes and post structured updates to the right Slack channel. Reps stop checking the CRM all day.

HubSpot

Slack

View agent

Why Scalekit

Secure your agent's access. Connectors ship in minutes

Other connector libraries treat auth as a demo afterthought. Scalekit starts with user identity, scope enforcement, and audit.

01.

Campaigns sent from the wrong sender identity

A shared Customer.io API key looks fine in a demo. In production, every transactional send and event track appears as a service account. Attribution breaks. Scalekit resolves the actual user's key so sends come from the right identity.

// shared API key
key = "api_customerio_shared_xxx"
audit → bot_service_account
user_filter → broken

// scalekit · per-user
key = resolve(user_id)
audit → user_abc
scope → enforced ✓

02.

Authentication is not authorization

03.

Multi-tenancy is architectural

04.

Customer.io MCP today. Others tomorrow.

“Our agents act across Salesforce, Gong, Google Drive, and more, on behalf of every customer. Scalekit behind the scenes meant we can keep adding tools without ever rebuilding how credentials or tool calling work.”

Venu Madhav Kattagoni

Head of Engineering / Von

FAQs

Frequently Asked Questions

Does the agent access Customer.io MCP as the user or as a shared key?

As the user. Each workspace member authorizes once and Scalekit resolves their credential at request time. Audit logs attribute every action to that user, not a shared service account.

Where is the Customer.io MCP api key stored?

In Scalekit's managed AES-256 token vault, namespaced per tenant. Refresh is automatic. Revocation is a single dashboard action. Tokens never appear in prompts, logs, or LLM context.

Can I limit what the agent is allowed to do in Customer.io MCP?

Yes. Pass a tool name filter to listScopedTools so the marketing automation agent only sees the subset you authorize. Pre-API-call scope checks block out-of-policy actions before the request reaches Customer.io MCP.

What happens when a user revokes Customer.io MCP access?

The connection is invalidated on the next tool call. Subsequent requests for that user fail closed with a clear error. Other users in the tenant remain unaffected. The event is logged for audit.

Can the agent send messages to any customer in the workspace?

Only customers the authorizing user's API key has access to. Customer.io API key scope determines which workspace and data center is accessible. A key scoped to one workspace cannot reach another, and send quotas apply per key.

Tools your marketing automation agent reaches for on Customer.io MCP, scoped per user.