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# Mailjet API and MCP server

> Mailjet has a full REST API (v3) for contacts, segments, campaign drafts, scheduling, sending and statistics, and an official MCP server that is read-only: it does not send emails or change Mailjet settings (checked 22 Oct 2026). The MCP server runs on your computer with an API key and secret.

Email platform for marketing campaigns and transactional email: contact lists and segments, a drag and drop Email Editor, automations, campaign statistics and an API.

## What is the Mailjet API?

Cotlet's Mailjet API exposes 14 endpoints for your own Mailjet account: list contact lists, list contacts, list segments, list campaigns, get campaign report, list campaign activity, create segment, duplicate campaign, update campaign, set campaign recipients, schedule campaign, send campaign, unschedule campaign and unsubscribe contacts. The list_contact_lists endpoint returns contact lists of your Mailjet account with their subscriber counts. Each endpoint takes simple JSON inputs like campaign_id, list_id or segment and works both as an operation of the mailjet_read or mailjet_write MCP tool for agents and as a REST call for scripts.

- **Category:** [Marketing & SEO](https://cotlet.dev/integrations/category/marketing-seo.md)
- **Endpoints:** 14 (6 read, 8 write)
- **Updated:** 2026-10-20

Mailjet has a full REST API (v3) for contacts, segments, campaign drafts, scheduling, sending and statistics, and an official MCP server that is read-only: it does not send emails or change Mailjet settings (checked 22 Oct 2026). Cotlet is a hosted MCP server and REST API for Mailjet with 14 endpoints (6 read, 8 write): you sign in once in your own cloud browser, your AI agent does the work.

## Does Mailjet have an official API?

Mailjet has a full REST API (v3) for contacts, segments, campaign drafts, scheduling, sending and statistics, and an official MCP server that is read-only: it does not send emails or change Mailjet settings (checked 22 Oct 2026). The MCP server runs on your computer with an API key and secret.

| Task | Mailjet official | Cotlet |
|---|---|---|
| List contact lists and contacts | Yes: REST API v3; the official MCP reads them too | Yes |
| Read campaign statistics | Yes: REST API statistics endpoints; the official MCP reads statistics but cannot act on them | Yes |
| List who opened, clicked or bounced | Partly: REST API reads statistics per contact, per link and per mail provider | Yes |
| Create a segment | Yes: REST API contact filters; the read-only MCP cannot create one | Yes |
| Unsubscribe or remove contacts in bulk | Yes: REST API manage-many-contacts; the read-only MCP cannot change contacts | Yes |
| Duplicate a campaign | Partly: REST API creates and updates drafts; copying a campaign is a Dashboard action | Yes |
| Set the subject, sender and recipients of a draft | Yes: REST API drafts; not in the read-only MCP | Yes |
| Schedule or send a campaign | Yes: REST API schedule and send; the official MCP does not send emails | Yes |

Sources: [Mailjet Help: Installing the Mailjet MCP Server](https://documentation.mailjet.com/hc/en-us/articles/42810091203867-Installing-the-Mailjet-MCP-Server), [Mailjet API reference: Campaigns](https://dev.mailjet.com/email/reference/campaigns/drafts/), [Mailjet API reference: Contacts](https://dev.mailjet.com/email/reference/contacts/contact-list/), [Mailjet API reference: Segmentation](https://dev.mailjet.com/email/reference/segmentation/)

## For AI agents

```text
Mailjet has a full REST API (v3) for contacts, segments, campaign drafts, scheduling, sending and statistics, and an official MCP server that is read-only: it does not send emails or change Mailjet settings (checked 22 Oct 2026). The MCP server runs on your computer with an API key and secret.
Cotlet provides a hosted MCP server and REST API for Mailjet: 14 tools (6 read, 8 write).
Access       Sign up at https://cotlet.dev/app/signup?app=mailjet, then request the app and create API keys in the Cotlet console.

MCP server   https://cotlet.dev/mcp/v1
MCP tools    mailjet_read, mailjet_write, reads and writes apart; call one with {"operation": "<operation>", "arguments": {...}}
REST base    https://cotlet.dev/api/v1/mailjet, each operation at its own route, e.g. POST /api/v1/mailjet/campaigns/{campaign_id}/schedule
Auth         Authorization: Bearer <COTLET_API_KEY>. Listing endpoints and schemas needs no key; calling an endpoint needs one. Over MCP the input schemas come with sign-in.
Operations   list_contact_lists, list_contacts, list_segments, list_campaigns, get_campaign_report, list_campaign_activity, create_segment, duplicate_campaign, update_campaign, set_campaign_recipients, schedule_campaign, send_campaign, unschedule_campaign, unsubscribe_contacts
Confirm      schedule_campaign, send_campaign, unsubscribe_contacts (by default the user approves each call; the user can switch this off per tool, e.g. for scheduled automations)
Markdown     https://cotlet.dev/integrations/mailjet-api-mcp-server.md

How access works:
1. The user signs up at https://cotlet.dev/app/signup?app=mailjet, requests Mailjet in the Cotlet console and creates an API key there.
2. The user signs in to Mailjet once in their Cotlet Cloud Browser (their own Chrome in the cloud, opened from the console) and enables Mailjet for agents. An agent cannot do this step.
3. The API key goes into the MCP client or the REST call as a bearer token.

Fits: people who want a hosted Mailjet server that someone else maintains, including non-developers. Developers who prefer to run and fix code on their own computer can use an open-source Mailjet MCP server instead.

Policy: Cotlet never stores passwords, never solves CAPTCHAs, never bypasses MFA.
Company: legal details in the Terms of service at https://cotlet.dev/terms. Contact contact@cotlet.dev.
Sign-in: the user signs in to Mailjet in their own Cloud Browser, a Chrome Cotlet runs for them in the EU; password saving is off, the profile is AES-256-GCM encrypted, and agents get Mailjet only after the user enables it. Calls are requests from that browser's IP with its cookies, each listed in the user's Background activity. Disable for agents, signing out in the browser or Reset browser cuts access. Cotlet is run by Take Group sp. z o.o. (EU VAT PL6342984273).
API key: holds no Mailjet login or cookies, only asks Cotlet to run a tool. Each key is scoped to chosen apps and tools, read only or read and write. Actions that reach other people wait for the user's approval by default, so a leaked key cannot post or message as the user. Every call is in the activity log; deleting the key ends access at once.
Terms: the user stays responsible for following Mailjet's terms; Cotlet is not affiliated with Mailjet.
```

## What can an AI agent do in Mailjet?

Cotlet is best for newsletter owners who run campaigns from the Mailjet dashboard and want their AI agent to segment, resend, schedule and clean lists without running or fixing a server.

- **[Resend a campaign to non-openers](https://cotlet.dev/integrations/mailjet-api-mcp-server/resend-campaign-to-non-openers.md)**: "In Mailjet, check how the "Autumn offer" campaign did. Make a segment of everyone on the Newsletter list who did not open it, duplicate the campaign with the subject "Last chance: Autumn offer", send it to that segment and schedule it for Monday 8:00 London time." → `get_campaign_report`, `create_segment`, `duplicate_campaign`, `update_campaign`, `set_campaign_recipients`, `schedule_campaign`
- **[Exclude inactive contacts from campaigns](https://cotlet.dev/integrations/mailjet-api-mcp-server/exclude-inactive-contacts.md)** (runs: weekly): "In Mailjet, find subscribers on my Newsletter list who have not opened anything in 180 days and did not click "Yes, keep me subscribed" in the Reconfirm October campaign. Show me how many there are, then exclude them from campaigns." → `create_segment`, `list_contacts`, `unsubscribe_contacts`
- **[Schedule the next newsletter from the last one](https://cotlet.dev/integrations/mailjet-api-mcp-server/schedule-next-newsletter.md)** (runs: weekly): "Duplicate last week's "Weekly digest" campaign in Mailjet, set the subject to "This week at Northside, Oct 23", send it to the Newsletter list and schedule it for Friday 8:00 London time." → `list_campaigns`, `duplicate_campaign`, `update_campaign`, `set_campaign_recipients`, `schedule_campaign`
- **Weekly campaign report** (runs: weekly): "Every Monday, list the campaigns I sent last week with delivered, opened, clicked and unsubscribed counts, and name the one with the most clicks." → `list_campaigns`, `get_campaign_report`
- **Clear blocked and bounced contacts**: "List the contacts that hard-bounced or were blocked in the "Autumn offer" campaign and exclude them from campaigns." → `list_campaign_activity`, `unsubscribe_contacts`

## Can Mailjet automations run on a schedule in n8n, Make or Zapier?

Yes. Cotlet does not replace your automation platform: it gives it a Mailjet connection it does not have, with the same API key as your agent. Write actions ask for your OK by default; switch that off in your dashboard for the tools you choose, for example to exclude inactive contacts from campaigns, and the schedule runs on its own. Cotlet runs in the cloud, so it keeps going while your computer is off.

| Where | How to connect | How to schedule |
|---|---|---|
| Your AI agent | Add https://cotlet.dev/mcp/v1 with your API key. | A scheduled agent run, for example a Claude Code routine. |
| n8n | MCP Client node with https://cotlet.dev/mcp/v1, or an HTTP Request node with the endpoint's method and URL, such as POST https://cotlet.dev/api/v1/mailjet/segments. | Schedule Trigger node. |
| Make | HTTP module: the endpoint's method and URL with an Authorization: Bearer header, and a JSON body for POST, PUT and PATCH. | Scenario schedule. |
| Zapier | Webhooks by Zapier, Custom Request: the same method, URL, header and body. | Schedule by Zapier trigger. |
| Your own script | POST https://cotlet.dev/api/v1/mailjet/segments with your API key. | cron or GitHub Actions. |

## Tools

**For AI agents:** Every endpoint and its schema is public. The 14 endpoints on this page, with parameters and example responses, can be listed without an account. Calling one returns 401 without an API key and 403 while the key has no access to Mailjet.

### list_contact_lists

Contact lists of your Mailjet account with their subscriber counts. Access: read. REST: `GET /api/v1/mailjet/contact-lists`. MCP: `mailjet_read → list_contact_lists`.

No parameters.

Returns every contact list with its list_id, name and number of subscribers, the same as Contacts, then Contact Lists. Use list_id as the list_id parameter of the other tools. A new account has one list, MyFirstTest, with your own address.

Example response:

```json
{
  "lists": [
    {
      "list_id": 10234567,
      "name": "Newsletter",
      "subscribers": 4203
    },
    {
      "list_id": 10234588,
      "name": "Workshop waitlist",
      "subscribers": 214
    }
  ]
}
```

### list_contacts

Contacts of one list with their properties, filtered by segment or email address. Access: read. REST: `GET /api/v1/mailjet/lists/{list_id}/contacts`. MCP: `mailjet_read → list_contacts`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `list_id` | integer | yes | Contact list ID from list_contact_lists. |
| `segment` | string | no | Name of a segment from list_segments. |
| `search` | string | no | A complete email address to look for. |
| `cursor` | string | no | next_cursor from the previous call. |

Lists the contacts of one contact list with their email address, subscription state and contact properties such as first name. segment narrows it to a segment from list_segments, and search matches a complete email address. Pass next_cursor back as cursor for the next page. The response also carries the total number of matching contacts.

Example response:

```json
{
  "total": 197,
  "contacts": [
    {
      "email": "sam@example.com",
      "subscribed": true,
      "properties": {
        "firstname": "Sam",
        "country": "GB"
      }
    },
    {
      "email": "lena@example.org",
      "subscribed": true,
      "properties": {
        "firstname": "Lena",
        "country": "DE"
      }
    }
  ],
  "next_cursor": "2"
}
```

### list_segments

Segments from Contacts, then Segmentation, with their filters. Access: read. REST: `GET /api/v1/mailjet/segments`. MCP: `mailjet_read → list_segments`.

No parameters.

Returns the segments on the My Segments page with their segment_id, name and a plain-language summary of the filters. Use the name as the segment parameter of list_contacts, set_campaign_recipients and unsubscribe_contacts.

Example response:

```json
{
  "segments": [
    {
      "segment_id": 2938471,
      "name": "Did not open: Autumn offer",
      "filters": "Not opened the campaign \"Autumn offer\" AND is subscribed to list \"Newsletter\""
    },
    {
      "segment_id": 2951108,
      "name": "Subscribers in Germany",
      "filters": "Property country is \"DE\""
    }
  ]
}
```

### list_campaigns

Campaigns of your account with their status, subject and list. Access: read. REST: `GET /api/v1/mailjet/campaigns`. MCP: `mailjet_read → list_campaigns`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `status` | enum | no | draft, scheduled or sent. Default: all three. |
| `search` | string | no | Part of the campaign name. |
| `cursor` | string | no | next_cursor from the previous call. |

Returns campaigns newest first with campaign_id, name, subject, status, the list they go to and, for sent ones, the send date. status filters by draft, scheduled or sent, and search matches part of the name. Pass next_cursor back as cursor for the next page.

Example response:

```json
{
  "campaigns": [
    {
      "campaign_id": 7164820931,
      "name": "Autumn offer",
      "subject": "Autumn offer: 20% off your next loaf",
      "status": "sent",
      "list": "Newsletter",
      "sent_at": "2026-10-14T08:00:00+01:00"
    },
    {
      "campaign_id": 7154402217,
      "name": "Weekly digest, Oct 15",
      "subject": "This week at Northside, Oct 15",
      "status": "sent",
      "list": "Newsletter",
      "sent_at": "2026-10-15T08:00:00+01:00"
    }
  ],
  "next_cursor": "2"
}
```

### get_campaign_report

Delivery and engagement numbers of one sent campaign. Access: read. REST: `GET /api/v1/mailjet/campaigns/{campaign_id}/report`. MCP: `mailjet_read → get_campaign_report`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |

Returns what the Overview tab of the campaign statistics shows: send date, subject, list, segment and sender, then delivered, opened, clicked, unsubscribed, marked as spam, blocked, soft-bounced and hard-bounced counts. A campaign still collecting opens returns the numbers so far. A draft has no report and returns an error.

Example response:

```json
{
  "campaign_id": 7164820931,
  "name": "Autumn offer",
  "subject": "Autumn offer: 20% off your next loaf",
  "sent_at": "2026-10-14T08:00:00+01:00",
  "list": "Newsletter",
  "segment": null,
  "sender": "Northside Bakery <hello@northside.example>",
  "delivered": 1840,
  "opened": 702,
  "clicked": 96,
  "unsubscribed": 9,
  "marked_as_spam": 1,
  "blocked": 6,
  "soft_bounced": 4,
  "hard_bounced": 2
}
```

### list_campaign_activity

Contacts behind one count of a campaign: who opened, clicked, bounced or was blocked. Access: read. REST: `GET /api/v1/mailjet/campaign-activities`. MCP: `mailjet_read → list_campaign_activity`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |
| `event` | enum | yes | opened, clicked, unsubscribed, spam, blocked, soft_bounced, hard_bounced or retrying. |
| `email` | string | no | A complete email address to look for. |
| `cursor` | string | no | next_cursor from the previous call. |

Returns the contacts of one status of a campaign, as the Activity and Non-delivery tabs list them. For blocked and bounced statuses each row has the reason and the date. email matches a complete address. Pass next_cursor back as cursor for the next page.

Example response:

```json
{
  "total": 2,
  "activity": [
    {
      "email": "old.address@example.net",
      "event": "hard_bounced",
      "reason": "User unknown",
      "at": "2026-10-14T08:02:11+01:00"
    },
    {
      "email": "info@closed-shop.example",
      "event": "hard_bounced",
      "reason": "Domain not found",
      "at": "2026-10-14T08:02:40+01:00"
    }
  ],
  "next_cursor": null
}
```

### create_segment

Create a segment from activity, list and contact property filters. Access: write. REST: `POST /api/v1/mailjet/segments`. MCP: `mailjet_write → create_segment`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `name` | string | yes | Name of the segment. |
| `match` | enum | no | all (AND) or any (OR). Default: all. |
| `conditions` | array | yes | Filters as {type, value}. type: campaign_opened, campaign_not_opened, campaign_clicked or campaign_not_clicked (value: campaign_id); opened_last_days, not_opened_last_days, clicked_last_days or not_clicked_last_days (value: number of days); subscribed_to_list or not_subscribed_to_list (value: list_id); property (also field, operator and value). |
| `list_id` | integer | no | List to count the matching contacts against. |

Does what Create a segment does on the Segmentation page. match "all" combines the filters with AND and "any" with OR. Pass list_id to get the number of contacts that match, as Calculate number of contacts does. The segment reaches no one and is undone by deleting it in the Dashboard, so it does not wait for your OK. Mailjet recalculates it at send time.

Example response:

```json
{
  "segment_id": 2938471,
  "name": "Did not open: Autumn offer",
  "match": "all",
  "conditions": 2,
  "matching_contacts": 1121,
  "list_id": 10234567
}
```

### duplicate_campaign

Copy a sent or draft campaign into a new draft. Access: write. REST: `POST /api/v1/mailjet/campaigns/{campaign_id}/duplicate`. MCP: `mailjet_write → duplicate_campaign`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |
| `name` | string | no | Name of the new draft. Only you see it. |

Does what Duplicate in the cogwheel menu of the Campaigns page does. The copy is a draft with the same design, list and sender. The draft reaches no one and you can delete it from the Draft tab, so it does not wait for your OK.

Example response:

```json
{
  "campaign_id": 7182934615,
  "name": "Autumn offer, last chance",
  "status": "draft",
  "copied_from": 7164820931
}
```

### update_campaign

Change the name, subject or sender of a draft campaign. Access: write. REST: `PATCH /api/v1/mailjet/campaigns/{campaign_id}`. MCP: `mailjet_write → update_campaign`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |
| `name` | string | no | Campaign name. Only you see it. |
| `subject` | string | no | Subject line, up to 100 characters. |
| `sender_name` | string | no | From name. |
| `sender_email` | string | no | From address you own or manage in Mailjet. |

Sets the campaign name, the subject line and the From name and address of a draft. A scheduled or sent campaign cannot be edited and returns an error. The sender address must be one you may use in Mailjet. The design is not touched. The change reaches no one and is undone by calling the tool again, so it does not wait for your OK.

Example response:

```json
{
  "campaign_id": 7182934615,
  "name": "Autumn offer, last chance",
  "subject": "Last chance: Autumn offer",
  "sender": "Northside Bakery <hello@northside.example>",
  "status": "draft"
}
```

### set_campaign_recipients

Choose the contact list and optional segment a draft campaign goes to. Access: write. REST: `PUT /api/v1/mailjet/lists/{list_id}/campaigns/{campaign_id}/recipients`. MCP: `mailjet_write → set_campaign_recipients`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |
| `list_id` | integer | yes | Contact list ID from list_contact_lists. |
| `segment` | string | no | Name of a segment from list_segments. Default: the whole list. |

Does what the Contact list field and "Only send to a segment" do on the Create a new campaign page. A campaign goes to one list, and a segment narrows that list. Nothing is sent. The change reaches no one and is undone by calling the tool again, so it does not wait for your OK.

Example response:

```json
{
  "campaign_id": 7182934615,
  "list": "Newsletter",
  "segment": "Did not open: Autumn offer",
  "status": "draft"
}
```

### schedule_campaign

Schedule a draft campaign to send at a set time. Access: write, asks the user first. REST: `POST /api/v1/mailjet/campaigns/{campaign_id}/schedule`. MCP: `mailjet_write → schedule_campaign`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |
| `send_at` | string | yes | ISO 8601 date and time with offset, for example 2026-10-23T08:00:00+01:00. |

Does what scheduling on the Review & Send page does. send_at is an ISO 8601 date and time with an offset, up to 60 days ahead, and the response returns the time Mailjet stored. Mailjet does not let you edit a scheduled campaign: use unschedule_campaign first. It reaches your contacts. By default you confirm each call; you can switch that off for this tool.

Example response:

```json
{
  "campaign_id": 7203318846,
  "name": "Weekly digest, Oct 23",
  "subject": "This week at Northside, Oct 23",
  "status": "scheduled",
  "scheduled_for": "2026-10-23T08:00:00+01:00"
}
```

### send_campaign

Send a draft campaign now. Access: write, asks the user first. REST: `POST /api/v1/mailjet/campaigns/{campaign_id}`. MCP: `mailjet_write → send_campaign`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |

Does what Send now on the Review & Send page does. The campaign goes to its list or segment at once and cannot be recalled. On the Free plan a campaign made in the Email Editor reaches at most 200 addresses, and an account over 1,000 stored contacts is on a sending hold, which removes Send now. By default you confirm each call; you can switch that off for this tool.

Example response:

```json
{
  "campaign_id": 7182934615,
  "name": "Autumn offer, last chance",
  "status": "sending",
  "recipients": 1121
}
```

### unschedule_campaign

Cancel the schedule of a campaign so it can be edited. Access: write. REST: `POST /api/v1/mailjet/campaigns/{campaign_id}/unschedule`. MCP: `mailjet_write → unschedule_campaign`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `campaign_id` | integer | yes | Campaign ID from list_campaigns. |

Cancels the scheduled send, which Mailjet requires before you can change a scheduled campaign. The campaign returns to draft with its content, list and segment. It stops mail instead of sending it and is undone with schedule_campaign, so it does not wait for your OK.

Example response:

```json
{
  "campaign_id": 7203318846,
  "name": "Weekly digest, Oct 23",
  "status": "draft"
}
```

### unsubscribe_contacts

Unsubscribe contacts from a list or exclude them from all campaigns. Access: write, asks the user first. REST: `POST /api/v1/mailjet/contacts/unsubscribe`. MCP: `mailjet_write → unsubscribe_contacts`.

| Parameter | Type | Required | Description |
|---|---|---|---|
| `scope` | enum | yes | list or exclusion_list. |
| `list_id` | integer | no | Contact list ID. Required when scope is list. |
| `segment` | string | no | Name of a segment from list_segments. |
| `emails` | array | no | Email addresses to unsubscribe or exclude. Give emails or segment, not both. |

Give a segment or a list of emails. scope "list" unsubscribes the contacts from the list in list_id and keeps them on it. scope "exclusion_list" adds them to the Campaign Exclusion List, so they get no campaign or automation email from any list, but still get transactional email. The tool never deletes a contact, because Mailjet deletes are permanent. By default you confirm each call; you can switch that off for this tool.

Example response:

```json
{
  "scope": "exclusion_list",
  "segment": "No answer to reconfirmation",
  "excluded": 197
}
```

## How do I connect Mailjet to Claude Code, Codex or Cursor?

Connecting Mailjet takes three steps: sign up, sign in to Mailjet once in your Cloud Browser and enable it for agents, then add one MCP server or call the REST API with the same key.

### Connect Mailjet to your agent.

1. **Create an account** Sign up and add Mailjet in the console. Your API key is there too.

2. **Sign in to Mailjet in your Cloud Browser** Open your Cloud Browser in the console: your own Chrome in the cloud. Sign in to Mailjet there yourself, the way you always do, then press Enable for agents, read only or read and write. We never save your password, and your agent keeps working even when your computer is off.

3. **Add Cotlet to your agent** Paste the snippet for your client. The same server and key serve every app you connect, so you do this once.

   Claude Code:

```
claude mcp add --transport http cotlet \
  https://cotlet.dev/mcp/v1 \
  --header "Authorization: Bearer $COTLET_API_KEY"
```

   Cursor:

```
{
  "mcpServers": {
    "cotlet": {
      "url": "https://cotlet.dev/mcp/v1",
      "headers": {
        "Authorization": "Bearer ${COTLET_API_KEY}"
      }
    }
  }
}
```

   Codex:

```
# ~/.codex/config.toml
[mcp_servers.cotlet]
url = "https://cotlet.dev/mcp/v1"
bearer_token_env_var = "COTLET_API_KEY"
```

4. **Ask your agent** Ask in plain words. Your agent finds the Mailjet tools on the server and calls them for you; anything that reaches other people waits for your OK unless you switch that off for a tool.

```
In Mailjet, check how the "Autumn offer" campaign did. Make a segment of everyone on the Newsletter list who did not open it, duplicate the campaign with the subject "Last chance: Autumn offer", send it to that segment and schedule it for Monday 8:00 London time.
```

### Call Mailjet from your scripts.

1. **Export your API key** Your scripts use the same API key as your agent. Keep it in an environment variable, never in your code.

```
export COTLET_API_KEY="cotlet_..."
```

2. **Call a tool** Every tool is an endpoint under /api/v1/mailjet with its own method and path, listed with the endpoints above. Path parameters go in the URL; the other parameters go in the query for GET and DELETE and in a JSON body otherwise.

```
curl -X POST https://cotlet.dev/api/v1/mailjet/campaigns/7203318846/schedule \
  -H "Authorization: Bearer $COTLET_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"send_at":"2026-10-23T08:00:00+01:00"}'
```

3. **Read the result** You get plain JSON back, ready for your script. A failed call costs nothing.

```
{
  "campaign_id": 7203318846,
  "name": "Weekly digest, Oct 23",
  "subject": "This week at Northside, Oct 23",
  "status": "scheduled",
  "scheduled_for": "2026-10-23T08:00:00+01:00"
}
```

## Why use Cotlet for Mailjet?

**Built for agents**

- One MCP server for every app you connect.
- The same tools as a REST API for scripts and cron jobs.
- Works with Claude Code, Codex and Cursor.

**Your login stays yours**

- You sign in to Mailjet yourself, in your own Cloud Browser. We never save your password; the profile is encrypted with AES-256-GCM, the cipher 1Password uses.
- A+ on Qualys SSL Labs, securityheaders.com and Mozilla Observatory.
- The model never sees a login.
- No stored passwords, no CAPTCHA solving, no MFA bypass.

**You stay in control**

- Scope each API key: its apps, its tools, read only or read and write.
- Anything that reaches other people waits for your OK, so a leaked key cannot post or message as you.
- Every background request listed in your Background activity. Disable for agents in one click.

**Kept working for you**

- We test every integration every 6 hours.
- When Mailjet changes, the tool pauses until we fix it.
- Failed calls cost nothing.

## Is it safe to connect Mailjet to Cotlet?

Yes. You sign in to Mailjet yourself, in your own Cloud Browser, and we never save your password. Your agents only get Mailjet once you enable it, and every background request is listed. The browser profile is stored encrypted with AES-256-GCM, the same cipher 1Password uses for its vaults and Apple for iCloud Keychain. Independent public scanners grade cotlet.dev A+ and find it clean; click a result to rerun it yourself.

- **A+ on Qualys SSL Labs**: Encryption in transit: TLS setup and certificates, on all four server addresses. [Live result](https://www.ssllabs.com/ssltest/analyze.html?d=cotlet.dev)
- **A+ on securityheaders.com**: Browser protections sent with every page, all six headers present. [Live result](https://securityheaders.com/?q=cotlet.dev&followRedirects=on)
- **A+ on Mozilla Observatory**: Mozilla's web security baseline: score 120 of 100, 12 of 12 tests passed. [Live result](https://developer.mozilla.org/en-US/observatory/analyze?host=cotlet.dev)
- **Clean on Sucuri SiteCheck**: No malware, spam or defacement, and not on any of 9 blocklists, Google Safe Browsing included. [Live result](https://sitecheck.sucuri.net/results/cotlet.dev)

[How Cotlet protects your access](https://cotlet.dev/security.md)

### Common concerns

**Who runs Cotlet?**

Cotlet is run by Take Group, a Polish software company working since 2019. Take Group runs about 3,200 websites on its own systems and has its own DevOps team for infrastructure security. We built and used integrations like this inside the company for years before opening them as Cotlet.

**Is this an official Mailjet integration?**

No, Cotlet is independent of Mailjet. Mailjet's own API is too limited for this work. Cotlet works through your own Mailjet account, the way you use Mailjet in the browser, so you need no partner approval and no developer setup.

**What about client data and GDPR?**

Cotlet is run from the EU and follows the GDPR. Cloud Browsers run in Finland, a Tier 1 country in the ITU Global Cybersecurity Index 2024. Data passes through a call and is not kept after it.

**Can I start with read only?**

Yes. Enable the app for agents as read only, or make the API key read only, and anything that reaches other people waits for your OK unless you switch that off per tool.

**Is it reliable?**

Every Cotlet service is checked every 3 minutes from Europe, North America, Asia and Australia. The live results and any outage are public at status.cotlet.dev.

**How do I stop?**

Press Disable for agents next to Mailjet in your console: your agents lose access at once and you stay signed in. Signing out of Mailjet in the browser works too, and Reset browser deletes the whole profile.

## Is there a Mailjet MCP server on GitHub?

Yes. Mailjet publishes an open-source MCP server on GitHub, and others exist, usually maintained by one person. The official one is read-only: it answers questions about your account but sends and changes nothing. You install it on your own computer with Git, Node.js and your API key and secret, and you keep it running yourself. Cotlet hosts a server that also segments, duplicates, schedules and sends, and our team keeps it working.

|  | GitHub MCP server | Cotlet |
|---|---|---|
| Setup | Clone the repo, install it, add your API key and secret to each MCP client | Sign up, sign in to Mailjet once, add one MCP server or API key |
| When Mailjet changes | It breaks until you or the maintainer fix it | Our team tests it daily and fixes it for you; failed calls are free |
| Your Mailjet access | An API key and secret in a config file on your computer, readable by any program you run | Your sign-in lives in your own Cloud Browser in the EU, profile encrypted, only for the apps you enable, disabled for agents in one click |
| When access ends | Calls fail until you create a new key or reset the secret | Your Cloud Browser keeps you signed in; if Mailjet logs you out, your agent gets a link to sign in again |
| Upkeep | You update, monitor and debug it yourself | Nothing to host or update |
| Where it runs | Your computer, while it is on | Hosted: Claude Code, Codex, Cursor, n8n and scripts, also on a schedule |
| Price | Free, paid for with your time | Free 7-day trial, then pay-as-you-go credit packs, no subscription |

### Which one fits you

**Pick Cotlet if**

- you are not a developer, or you do not want to maintain a server
- you need it to keep working when Mailjet changes, without checking it yourself
- your agent or a script should run it on a schedule, also while your computer is off

**Pick an open-source server if**

- you are comfortable installing, updating and fixing it yourself
- you want your sign-in to stay on your own computer
- you only need it now and then, from one MCP client

## How much does the Mailjet API cost?

Free 7-day trial with 2,000 credits, no card needed. After that, the Mailjet API is pay as you go with no limit on apps: Credit packs from $29 for 5,000 credits, one-time, no subscription. A successful call uses 20 to 30 credits (25 for most tools, about $0.10 to $0.15), your Cloud Browser uses 50 credits a day while it has an app enabled for agents, however many apps that is, and an agent driving the browser itself uses 5 credits a minute. Credit packs stay valid for 12 months and stack, so unused credits carry over.

| Credits | Price, one time | Calls at 25 credits | Per 1,000 credits |
|---|---|---|---|
| 5,000 | $29 | 200 | $5.80 |
| 15,000 | $79 | 600 | $5.27 |
| 32,000 | $149 | 1,280 | $4.66 |
| 60,000 | $249 | 2,400 | $4.15 |

Only successful calls use credits; failed calls and timeouts cost nothing. At a balance of 0 calls pause, never a surprise charge. Authenticate with the `Authorization: Bearer` header. [See full pricing](https://cotlet.dev/pricing.md)

## How Cotlet holds your access

Cotlet hosts MCP servers and REST APIs for apps with no usable API. Your agent works in your own Mailjet account.

- **Company details:** Cotlet is run by Take Group sp. z o.o., a company registered in Poland. Its full address and registration numbers are in the Terms of service. [Terms of service](https://cotlet.dev/terms)
- **Your sign-in:** You sign in to Mailjet yourself, in your own Cloud Browser: a Chrome we run for you in the EU, one per app. We never save your password (password saving is off), the profile is stored encrypted with AES-256-GCM, and your agents get Mailjet only after you enable it. When Mailjet signs you out, your agent gives you a link to sign in again. [Security](https://cotlet.dev/security.md)
- **Revoking access:** Press Disable for agents next to Mailjet, sign out of Mailjet in your Cloud Browser, or reset the browser. Every background request is listed in your Background activity. Actions that reach other people wait for your OK unless you switch that off per tool.
- **What we never do:** Store passwords, solve CAPTCHAs or bypass MFA.
- **Mailjet's terms:** You use your own Mailjet account and stay responsible for following Mailjet's terms. Cotlet is independent and not affiliated with Mailjet. [Terms](https://cotlet.dev/terms)
- **Contact:** Questions about the company, security or an app: [contact@cotlet.dev](mailto:contact@cotlet.dev)

## Frequently asked questions

**How do I get access?**

Sign up free, open Mailjet in the console and press Request access. Then you create your API key and connect Mailjet there.

**Do I need to be technical?**

No. You sign in to Mailjet once in your Cloud Browser, a normal Chrome you open from the console, and paste one command into your agent, or one URL into n8n. Your agent can walk you through it. There is no server to install, update or fix.

**Is it safe to connect Mailjet to Cotlet?**

Yes. You sign in to Mailjet yourself, in your own Cloud Browser in the EU, and we never save your password. Your agents only get Mailjet once you enable it, every background request is listed, and the browser profile is stored encrypted with AES-256-GCM, the cipher 1Password uses for its vaults. The AI model never sees a login, posts and messages wait for your OK, and Disable for agents cuts access in one click. Independent scanners grade cotlet.dev A+ on Qualys SSL Labs, securityheaders.com and Mozilla Observatory; live results are on https://cotlet.dev/security.

**Is a hosted server safer than a local one? My Mailjet sign-in would leave my computer.**

On Cotlet you sign in inside your own Cloud Browser, which only you open, and its profile is stored encrypted with AES-256-GCM in the EU. Agents get only the apps you enable, and every background request is listed. A local server keeps your Mailjet cookie in a plain file on your computer, readable by any program you run, and stops when your computer is off.

**Why does Cotlet send requests instead of clicking in my browser?**

To be fast, Cotlet doesn't click through Mailjet's pages. It sends the same requests your browser would, from your browser's IP with its cookies, without opening a window. Mailjet sees the same browser and IP you signed in with, and every request is listed in your Background activity.

**What if someone gets my Cotlet API key?**

The key holds no Mailjet login or cookies, it only asks Cotlet to run a tool. It can call only the apps and tools you gave it, and a read-only key changes nothing. Anything that reaches other people, like posts, comments or messages, waits for your OK in the dashboard by default, so a leaked key cannot post or message as you. When you switch approval off for a scheduled job, give that job its own key limited to that one tool. Every call is in your activity log, and deleting the key ends access at once.

**Why a signed-in browser and not OAuth, like other integration platforms?**

Mailjet offers no OAuth token you can simply grant for these tools: its official API leaves them out or needs a developer app, a plan or an approval first (see the official API section above). That is why Cotlet sets the limits itself: per key, per tool, with your approval before anything reaches other people. Cotlet is run by Take Group sp. z o.o., an EU company (VAT PL6342984273).

**Which Mailjet plan or role does my agent need?**

Cotlet works in the account you sign in with, so your plan and role still apply. Segments are included in Essential, Premium and Custom, not in Free or Starter. On the Free plan a campaign made in the Email Editor reaches at most 200 addresses and the account holds at most 1,000 contacts, with a sending hold above that. A shared user needs a role such as Marketer or Manager, and account sharing is a Premium and Custom feature (Mailjet Help: Segmentation guide, Free Plan Limits, Account Sharing).

**Can my agent design the email?**

No. The tools set the name, subject, sender, recipients and sending time of a campaign, and duplicate_campaign copies a campaign you already designed. The design stays in the drag and drop Email Editor or your own template.

**Can my agent post or send messages in Mailjet without asking me?**

No. Every call to schedule_campaign, send_campaign or unsubscribe_contacts waits for your OK by default. For scheduled automations you can switch confirmation off per tool in your dashboard, for example only for approvals. create_segment, duplicate_campaign, update_campaign, set_campaign_recipients, unschedule_campaign runs without asking, because it sends nothing to anyone and one call undoes it.

**Can I use the Mailjet API in n8n?**

Yes. Add https://cotlet.dev/mcp/v1 with your API key in n8n's MCP Client node, or call its endpoints under https://cotlet.dev/api/v1/mailjet from the HTTP Request node.

---

Give your AI agents your signed-in browser.

**Product:** [Integrations](https://cotlet.dev/integrations.md) · [Use cases](https://cotlet.dev/use-cases.md) · [How it works](https://cotlet.dev/how-it-works.md) · [Pricing](https://cotlet.dev/pricing.md) · [Security](https://cotlet.dev/security.md)

**Resources:** [Blog](https://cotlet.dev/blog.md) · [API docs](https://cotlet.dev/docs.md) · [Help center](https://cotlet.dev/help.md) · [Changelog](https://cotlet.dev/changelog.md) · [GitHub](https://github.com/cotletdev/cotlet)

**Solutions:** [For developers](https://cotlet.dev/for-developers.md) · [For automation agencies](https://cotlet.dev/for-agencies.md)

**Company:** [About](https://cotlet.dev/about.md) · [AI info: company facts](https://cotlet.dev/ai-info.md) · [Contact](https://cotlet.dev/contact.md)

**Legal:** [Terms of service](https://cotlet.dev/terms) · [Privacy policy](https://cotlet.dev/privacy) · [Refund policy](https://cotlet.dev/refunds) · [Acceptable use](https://cotlet.dev/acceptable-use) · [Cookie policy](https://cotlet.dev/cookies) · [DPA](https://cotlet.dev/dpa) · [Subprocessors](https://cotlet.dev/subprocessors)

**Elsewhere:** [Status page](https://status.cotlet.dev) · [Cotlet on GitHub](https://github.com/cotletdev) · [Cotlet on X](https://x.com/cotletdev) · [Cotlet on LinkedIn](https://www.linkedin.com/company/cotletdev) · [Cotlet on Product Hunt](https://www.producthunt.com/products/cotlet) · [Cotlet on Crunchbase](https://www.crunchbase.com/organization/cotlet) · [Cotlet on SaaSHub](https://www.saashub.com/cotlet)

Cotlet is an independent service. It is not affiliated with, endorsed by or sponsored by any of the products listed on this site. Product names are trademarks of their respective owners.

## For AI agents: sign your user up

Is your user asking you to sign them up for Cotlet? You can do it for them, no account or key needed.

1. Read the fields and their allowed values: GET https://cotlet.dev/api/v1/access-requests
2. Ask the user for each value: email, apps, what you will do with them. If they leave the password to you, generate a strong one and show it to them.
3. Show the user what you will send, then POST it as JSON to https://cotlet.dev/api/v1/access-requests.

One call creates the account and sends the access request; we email the user when access is granted.