---
title: "Linkbreakers + Kit: sync QR code subscribers to Kit with tags"
description: "Connect Kit (formerly ConvertKit) with a v4 API key and every person who scans your QR codes and gives their email becomes a Kit subscriber, tagged so your sequences and automations pick them up, with their first name and form answers in custom fields. Consent decides whether a new subscriber is active. Setup, what is synced, and the Assistant and MCP tools."
canonical: "https://linkbreakers.com/help/article/linkbreakers-kit-integration-sync-qr-code-subscribers-and-tags"
last-updated: 2026-11-09
---

# Linkbreakers + Kit: sync QR code subscribers to Kit with tags

> Connect Kit (formerly ConvertKit) with a v4 API key and every person who scans your QR codes and gives their email becomes a Kit subscriber, tagged so your sequences and automations pick them up, with their first name and form answers in custom fields. Consent decides whether a new subscriber is active. Setup, what is synced, and the Assistant and MCP tools.

:::try-ai-prompt {"prompt":"Connect Kit with my v4 API key, tag synced subscribers with my QR leads tag and qr-{link}, and use my form's Consent field as their marketing consent","description":"Connect Kit with the Assistant.","target":"assistant"}:::

## Short answer

Linkbreakers syncs the people who scan your QR codes to Kit (formerly ConvertKit) directly. In the dashboard, open **Integrations**, pick **Kit**, paste a Kit v4 API key and select **Connect**. From then on, every person who goes through one of your links or QR codes and whose email Linkbreakers knows, for example after a form, is created or updated as a Kit subscriber, with their first name and form answers, and tagged with the tag you choose plus any other tags you set. Tags are how Kit starts sequences and automations, so a tag is what puts the person in your flow.

No Zapier, Make or webhook is needed. The integration is available on every plan.

## Quick summary

- Connect once per workspace with a v4 API key from **Settings > Developer**
- Subscribers are created, or found by email and updated
- First name and form answers (as custom fields) are filled in
- One main tag, plus up to 10 more tags, with `{link}` for the link's name; tags that do not exist yet are created
- Marketing consent decides whether a new subscriber is active or inactive
- Visitors known only by phone are not synced: Kit subscribers need an email
- Also set up from the Assistant, the MCP server or the REST API

## How it works

A subscriber is synced when a visitor goes through a step of a link's workflow and Linkbreakers knows their email. That is usually right after a [form](/help/article/how-to-create-a-form), but it can also come from the chat bot or any step that saves visitor data. Linkbreakers sends the subscriber to Kit from its servers, once per step, at the moments the connection covers (all of them by default).

Kit finds the subscriber by email or creates them. Linkbreakers then writes the custom fields and adds the tags. Tags are only ever added, never removed, and tagging sends no email by itself: it is your Kit automations that act on it.

## Connect Kit

1. In Kit, open **Settings > Developer** and select **Add a new key** (a v4 API key).
2. In Linkbreakers, open **Integrations** in the dashboard and pick **Kit**.
3. Paste the key in **Kit API key (v4)** and select **Connect**. Linkbreakers checks it against Kit before storing it.
4. Under **Add contacts to a tag**, choose the tag subscribers get, or **No tag: contacts only**.
5. Set the options and the delivery setting below, then save.

The key is encrypted when it is stored and never shown again; the page shows the Kit account name.

## What gets synced

| Linkbreakers | Kit |
|---|---|
| Email | Subscriber email (the match) |
| First name | First name |
| Form answers and other visitor data | Custom fields with the same key, as text, or the one you map them to |
| The tag you chose | Added to the subscriber |
| Tags you set | Added to the subscriber, created in Kit if needed |

Kit stores every custom field as text. An answer goes to the custom field with the same key, such as `company`. Create custom fields in Kit under **Subscribers > Custom fields**, with the same keys as your form fields, or map an answer to a field on the Kit page. Up to 140 fields are written per subscriber. **Test connection** lists the field keys Linkbreakers can write to.

Kit subscribers have no last name or phone of their own, so the visitor's last name and phone are not sent to Kit.

## Options

**Tags.** Tags added to each subscriber, separated by commas, up to 10, each up to 100 characters. `{link}` becomes the name of the link the person came through, so `qr-{link}` tells you which QR code brought each subscriber. A tag the account does not have yet is created.

**Marketing consent.** Choose the answer where people agree to hear from you: the **Linkbreakers consent** (a Consent field on your form, or the marketing consent goal of the [chat bot](/help/article/how-to-add-an-ai-chat-bot-to-a-qr-code)), or any other answer, such as a checkbox of your own. You can also tick **Add to the tag only those who consented**: everyone is synced, only those who said yes get the main tag.

Kit's double opt-in belongs to its forms, and the connection holds a tag, not a form, so there is no double opt-in option for Kit.

## Marketing consent in Kit

Consent decides the state a new subscriber is created in:

- **With a consent answer chosen**: a new subscriber who said yes is created active; one who did not is created inactive, kept in Kit but not mailed
- **With no consent answer chosen**: new subscribers are created active, Kit's default
- **An existing subscriber keeps their state** either way, so someone who unsubscribed stays unsubscribed

If you only want to mail people who agreed, choose a consent answer.

## Which visitors and which links

The Kit page has the same three settings as the other Linkbreakers integrations:

- **Where**: every link, or only some links, directories and tags
- **When**: the moments of a visit (Entry, Interaction, Routing, Exit), or specific steps
- **What is sent**: all visitor data, only some, or just the visit. Email is always sent

Only visits by people are synced: bots, link previews and AI agents never become subscribers. Visits past your plan's tracked visits allowance are not synced.

## What is not synced

- Visitors without an email, including those known only by their phone. They are skipped, not counted as failures
- Last name and phone: Kit subscribers have neither
- Answers with no matching custom field
- Anything back from Kit

## Set it up from the Assistant, MCP or the API

**Assistant**: in the dashboard, ask "Connect Kit with my API key and tag new subscribers with QR leads".

**MCP server**: an agent connected to the [Linkbreakers MCP server](/help/article/mcp-server-setup) has `contact_integration_connect`, `contact_integration_lists` (the tags), `contact_integration_fields`, `contact_integration_update`, `contact_integration_test`, `contact_integration_get`, `contact_integrations_list` and `contact_integration_disconnect`, with the tool `CONTACT_TOOL_KIT`.

**REST API**, with a token that has the `integrations:write` scope:

```bash
curl -X POST https://api.linkbreakers.com/v1/integrations/contacts/CONTACT_TOOL_KIT/connect \
  -H "Authorization: Bearer $LINKBREAKERS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"apiKey": "your-kit-v4-key"}'

curl -X PATCH https://api.linkbreakers.com/v1/integrations/contacts/CONTACT_TOOL_KIT \
  -H "Authorization: Bearer $LINKBREAKERS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"contactListId": "1234567", "options": {"tags": ["qr-{link}"], "consentAttributeKey": "$marketingConsent"}}'
```

## Limits and caveats

- **Email required.** Phone-only visitors are skipped
- **One Kit account and one main tag per workspace**, plus up to 10 extra tags
- **No double opt-in** from Linkbreakers, since Kit's belongs to its forms
- **Without a consent answer, new subscribers are active**, as Kit makes them by default
- **No retries.** A subscriber Kit refuses is reported as the last error on the page, not sent again. If the chosen tag is deleted in Kit, the page asks you to choose another

## Frequently asked questions

### Why does Linkbreakers use a tag instead of a form or sequence?

Tagging is how Kit segments subscribers and starts automations, and unlike adding someone to a form it sends no email by itself. Build a Kit automation that starts on the tag to put people into a sequence.

### Are subscribers who did not consent mailed?

Not when you choose a consent answer: they are created inactive. Without a consent answer, Kit's default applies and they are active.

### Will someone who unsubscribed be subscribed again?

No. An existing subscriber keeps the state they have in Kit.

### Does the visitor's last name reach Kit?

No. Kit subscribers have a first name but no last name or phone of their own, so Linkbreakers sends the first name only.

### What happens when I disconnect Kit?

Visitors stop being synced and the stored key is deleted. Subscribers already in Kit stay there.

## Sources

- Linkbreakers Kit integration page, API and MCP tools, checked in the product on 2026-11-09.
- Kit API documentation: https://developers.kit.com/

## Last reviewed

2026-11-09 by Laurent Schaffner.