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Kit MCP server

16 operations0 webhooks

Email marketing with Kit (formerly ConvertKit) - manage subscribers, tags, custom fields and forms, subscribe an address through a form, unsubscribe a subscriber, and read the account with its plan and sending addresses.

Use Kit in Claude, ChatGPT, Cursor or another MCP client

Connect Kit once in Corsair, then add one MCP address to your agent.

Connect Kit
Setup steps for Claude, ChatGPT, Cursor and Claude Code

Building your own app on the Corsair SDK? Get API keys

Try Kit with your agent

Connect Kit, then paste this into Claude, ChatGPT or Cursor. For ideas from other apps, see the use cases.

Using Corsair, show me what you can do in Kit on my account, then run one read-only example and show me the result.

Runs once, when you ask

Kit tools and triggers

Tools are what your agent can do in Kit through Corsair's MCP server. Triggers are the Kit events a routine can start from.

Subscribers

  • CreateWrite

    Create a subscriber, or return the existing one for an address already on the list. Unknown custom field keys are ignored and named in `warnings`

    subscribers.create

  • GetRead-only

    One subscriber with their custom field values and location

    subscribers.get

  • ListRead-only

    Subscribers by state, address or date, cursor-paged, with optional attribution, tags and location

    subscribers.list

  • UnsubscribeDestructive

    Unsubscribe a subscriber, which stops every future send to them; re-subscribing takes their own action, not a call

    subscribers.unsubscribe

  • UpdateWrite

    Change a subscriber’s address, first name or custom field values

    subscribers.update

Tags

  • CreateWrite

    Create a tag, or return the existing one when the name is taken

    tags.create

  • ListRead-only

    Every tag, optionally with its active subscriber count

    tags.list

  • Tag SubscriberWrite

    Add a tag to an existing subscriber, found by email address

    tags.tagSubscriber

  • Untag SubscriberWrite

    Remove a tag from a subscriber, found by email address

    tags.untagSubscriber

  • UpdateWrite

    Rename a tag

    tags.update

Custom Fields

  • CreateWrite

    Create a custom field; Kit derives its `key` from the label

    customFields.create

  • ListRead-only

    Every custom field with the `key` a subscriber’s `fields` map uses

    customFields.list

Connect Kit to Claude, ChatGPT or Cursor

  1. 1

    Connect Kit in Corsair

    Add your Kit API key once in Corsair. Corsair stores the credential encrypted and makes the Kit API calls for your agent, so it never goes into a prompt or a config file. Connect Kit

    If your link lets the agent add apps, you can skip this: it gives you a sign-in link the first time it needs Kit. On a ChatGPT personal plan, connect Kit here first.

  2. 2

    Add Corsair's MCP server to your agent

    Every client uses the same address:

    https://mcp.corsair.dev/mcp
    Open Customize → Connectors → Add custom connector, paste the address, then select Connect.

    Codex, Gemini CLI, VS Code, Zed and other clients with OAuth sign-in work the same way. Clients without it, such as GitHub Copilot's coding agent, use a link's own address and an API key. Setup for every client

  3. 3

    Sign in and choose what needs your approval

    Your client opens Corsair to sign in. Pick a link: the apps your agent can use and a mode that decides what it may do without asking. In the default Cautious mode, Kit's read and write operations run right away and its 2 destructive operations wait for your approval. Strict mode asks before every write and refuses destructive operations, and Read mode allows reads only.

FAQ

Install corsair and @corsair-dev/kit, add the Kit plugin, and connect with an API key. Then call methods like corsair.kit.api.account.get() from your app. Corsair keeps each tenant isolated.

Yes. Kit requires an API key from your Kit account or developer dashboard. Create credentials with access that matches what you automate, then paste them into Corsair or connect through managed auth in Hub.

Yes. One Corsair client can hit Kit, GitHub, Notion, Stripe, and the rest. Trigger Kit from a webhook, push updates to Slack, or chain actions across plugins. Same tenant context across integrations, plain TypeScript.

Teams use Corsair for email marketing with Kit (formerly ConvertKit) - manage subscribers, tags, custom fields and forms, subscribe an address through a form, unsubscribe a subscriber, and read the account with its plan and sending addresses. Common builds include sync jobs, admin tooling, and agents that call Kit APIs from your backend.

The SDK is open source. Self-host and you pay Corsair nothing for the integration layer. Hub bills for hosted auth and execution, not per Kit API call. Hub has a generous free tier. For hobby projects you can probably run the whole thing on free. Paid plans start to matter with more tenants or heavier traffic.

We maintain @corsair-dev/kit in the open repo. When Kit ships API changes, upgrade the package. Your call sites stay typed. You should not need to rewrite the integration layer each time.

No. Corsair does not read your Kit data or hold individual access credentials. Credentials stay in your database. API calls run on your instance. We do not store Kit data on your behalf.

Yes. Add https://mcp.corsair.dev/mcp as a custom connector or MCP server in Claude, ChatGPT, Cursor, VS Code, Claude Code, Codex or any client that supports remote MCP servers with OAuth sign-in, then sign in to Corsair. On ChatGPT personal plans, custom servers currently get read tools only.

Yes. Put Kit on a link in Strict mode and every write waits for your approval, while destructive actions are refused. The default Cautious mode asks only before the 2 destructive Kit operations. You can change a link's mode at hub.corsair.dev/me.