Mailjet API

Name: Mailjet API API
Brand: Mailjet API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentCommunicationsEmail Deliverybasic25 EndpointsREST

For Agents

Send transactional email and manage Mailjet contacts, templates, and newsletter campaigns through a 25-endpoint surface that combines Send API v3.1 with REST v3 resources.

Quickstart

Get started with Mailjet API in minutes using your preferred integration method.

# Add to your MCP client config (Claude Desktop, Cursor, Windsurf)
{
  "jentic": {
    "url": "https://api.jentic.com/mcp",
    "auth": "oauth"
  }
}

# Then ask your agent:
"send a transactional email through mailjet"

# → Jentic returns the GET /events tool with parameter schema, agent executes.

Capabilities

What an agent can do with Mailjet API API.

Send transactional email through POST /v3.1/send with full attachment and template support

Create, list, and update contacts and contact lists for marketing sends

Subscribe and unsubscribe contacts in bulk via /managemanycontacts

Manage email templates with content read and update operations

GET STARTED

Start building with Mailjet API API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI document for Mailjet API, keeping it validated and agent-ready.

Jentic publishes the only available OpenAPI specification for Mailjet API, keeping it validated and agent-ready. Mailjet is a transactional and marketing email API that combines a Send API at /v3.1/send for outbound delivery with a REST API at /v3/REST for managing contacts, contact lists, templates, senders, statistics, and newsletter campaigns. The 25 endpoints in this spec cover the core operational surface for both transactional and marketing teams. Authentication is HTTP Basic with the API key as username and the secret key as password.

Use Cases

Patterns agents use Mailjet API API for, with concrete tasks.

★ Transactional Email from a Backend

Send transactional email such as order receipts and password resets from a backend by posting to /v3.1/send. The Send API v3.1 supports per-message templates, variables, attachments, and inline images, so a single call covers everything an application needs. Mailjet processes the request and returns per-message status that can be persisted for reconciliation.

POST /v3.1/send with Messages=[{From:{Email:hello@app.com},To:[{Email:jane@example.com}],Subject:"Receipt",HTMLPart:"..."}] and confirm Status is success.

Contact List Management

Manage marketing contact lists at scale by combining /v3/REST/contact and /v3/REST/contactslist with the bulk /managemanycontacts endpoint. The bulk endpoint accepts a list of contacts and an action (addnoforce, addforce, remove, unsub) so a single request can subscribe or remove hundreds of recipients without per-row HTTP overhead.

POST /v3/REST/contactslist/{list_id}/managemanycontacts with Action=addnoforce and Contacts as a list of 200 email/name pairs.

Template Lifecycle Updates

Automate template updates from a content workflow by reading current template content via GET /v3/REST/template/{template_id}/detailcontent, swapping in updated HTML, and posting it back through the same endpoint. Combined with /v3/REST/template (list and create) the workflow covers the full template lifecycle without leaving the API.

GET /v3/REST/template/12345/detailcontent, replace the HTML content, then POST the updated body back to the same endpoint.

Newsletter Campaign Scheduling

Build, list, and send newsletter campaign drafts through /v3/REST/newsletter, then trigger send via POST /v3/REST/newsletter/{newsletter_id}/send when ready. This lets a content team programmatically queue campaigns from a CMS workflow rather than relying on the Mailjet UI.

List drafts via GET /v3/REST/newsletter, find the one named "Spring sale", then POST /v3/REST/newsletter/{newsletter_id}/send to deliver it.

Agent-Driven Marketing Operations

An AI agent that runs marketing operations can use Mailjet through Jentic to manage lists, update templates, and trigger newsletter sends in one chained workflow. The basic-auth credentials live in the Jentic vault, so an autonomous agent can drive marketing sends without ever seeing the API or secret keys directly.

Update the Spring template content via /v3/REST/template/{id}/detailcontent, then send the matching newsletter draft via /v3/REST/newsletter/{id}/send and report the message id.

Key Endpoints

25 endpoints — jentic publishes the only available openapi specification for mailjet api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

POST

/v3.1/send

Send transactional email

POST

/v3/REST/contact

Create a contact

POST

/v3/REST/contactslist/{list_id}/managemanycontacts

Bulk-update contacts in a list

GET

/v3/REST/message/{message_id}

Get a single message

POST

/v3/REST/template/{template_id}/detailcontent

Update template content

POST

/v3/REST/newsletter/{newsletter_id}/send

Send a newsletter draft

POST

/v3.1/send

Send transactional email

POST

/v3/REST/contact

Create a contact

POST

/v3/REST/contactslist/{list_id}/managemanycontacts

Bulk-update contacts in a list

GET

/v3/REST/message/{message_id}

Get a single message

POST

/v3/REST/template/{template_id}/detailcontent

Update template content

Why though Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

The Mailjet API key and secret key pair is stored encrypted in the Jentic vault. Agents receive a scoped basic-auth token at execution time and the raw secret never enters agent context.

Intent-based discovery

Agents search Jentic by intent (e.g., "send a transactional email mailjet") and Jentic returns POST /v3.1/send with its input schema, ready to execute against the right path.

Time to first call

Direct Mailjet integration: 1-2 days to wire up basic auth, the dual v3.1/v3 path conventions, and 429 retry logic. Through Jentic: under 1 hour — search, load, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Alternative

SendGrid Mail Send

High-volume transactional email API from Twilio.

Choose SendGrid when send volume is very high, when the surrounding Twilio suite is in use, or when you prefer bearer-token auth over basic auth.

Alternative

MailerSend API

Transactional email API with bearer-token auth and a small endpoint surface.

Choose MailerSend when you only need transactional email and prefer a simpler 5-endpoint surface.

Alternative

Brevo (formerly Sendinblue)

Combined transactional, marketing, and SMS provider with a unified API.

Choose Brevo when SMS is needed in the same vendor as transactional and marketing email.

Complementary

mailboxlayer

Real-time email validation that runs before submitting to Mailjet.

Validate addresses through mailboxlayer before adding them to a Mailjet contact list to suppress likely bounces.

FAQs

Specific to using Mailjet API API through Jentic.

Why is there no official OpenAPI spec for Mailjet API?

Mailjet does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Mailjet API via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.

What authentication does the Mailjet API use?

Mailjet uses HTTP Basic authentication via the BasicAuth scheme. The username is your Mailjet API key and the password is the secret key — both are issued from the Mailjet dashboard. Through Jentic the pair is stored encrypted in the vault and injected into the Authorization header at execution time.

Can I send transactional email and manage marketing in one API?

Yes. The same auth covers both surfaces — POST /v3.1/send is the transactional Send API and the /v3/REST/* paths cover marketing resources such as contacts, lists, templates, and newsletters. This is why Mailjet positions itself as a single API for both transactional and marketing email.

What are the rate limits for the Mailjet API?

Rate limits depend on your Mailjet plan tier and are documented at dev.mailjet.com. The Send API supports high-throughput per-second rates on paid tiers, and the REST API has its own per-minute caps. The OpenAPI spec does not encode the limits, so watch for 429 responses and back off.

How do I bulk-subscribe contacts through Jentic?

Search Jentic for "bulk subscribe contacts mailjet" to load POST /v3/REST/contactslist/{list_id}/managemanycontacts, then execute with Action set to addnoforce and Contacts as the email/name list. The endpoint avoids per-contact HTTP overhead and is the right choice for hundreds of records at a time.

Is the Mailjet API free?

Mailjet includes API access on the free plan up to 6000 emails per month with a 200/day cap. Paid plans raise the volume cap and unlock advanced features such as dedicated IPs, segmentation, and per-message statistics.

Can I update template HTML through the API?

Yes. POST /v3/REST/template/{template_id}/detailcontent updates the HTML, MJML, and text parts of an existing template. Pair it with GET on the same path to read current content before swapping in updates from a content workflow.