MailerLite API
Email marketing platform API for managing subscribers, groups, campaigns, automations, and forms. Supports creating and sending email campaigns, managing subscriber lists and segments, tracking campaign analytics, and building email automation workflows programmatically.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
HTTPS enforced on all endpoints. API tokens passed as Authorization Bearer header (better than query param). No scope granularity - single token has full account access. No IP allowlist feature. Tokens do not expire by default, requiring manual rotation. GDPR-compliant data handling with EU data residency option.
⚡ Reliability
Best When
An agent needs to manage newsletter subscribers, trigger marketing email campaigns, or sync contact data with an email marketing list that uses the MailerLite platform.
Avoid When
You need transactional email, do not have properly opted-in subscriber consent, or require advanced CRM-style segmentation beyond email marketing.
Use Cases
- • Adding or updating subscribers programmatically from agent-driven signup flows
- • Triggering email campaigns or automation sequences based on agent-detected events
- • Syncing subscriber data and segments between CRM and MailerLite from an agent
- • Fetching campaign open/click analytics for reporting agents
- • Managing subscriber groups and fields for personalization workflows
Not For
- • Transactional email (one-to-one triggered emails) - use SendGrid or Postmark instead
- • Very large volume cold outreach - MailerLite requires opted-in subscribers
- • SMS or multi-channel marketing beyond email
Interface
Authentication
API token passed as Bearer token in Authorization header. Single token grants full account access with no scope granularity. Tokens are generated in the MailerLite dashboard and do not expire. Classic API and new API (v2) use separate token formats.
Pricing
Pricing is subscriber-count based, not request-based. API access included on all plans. Free tier is genuinely useful for small lists. New MailerLite (2022+) and Classic MailerLite have separate APIs - ensure you target the correct one.
Agent Metadata
Known Gotchas
- ⚠ New MailerLite API (2022+) and Classic API are entirely separate with different endpoints and authentication - agents must target the correct version based on account type
- ⚠ Sending a campaign is a two-step process: create campaign then POST to /campaigns/{id}/schedule - agents that only create campaigns will not send them
- ⚠ Rate limit of 60 requests/minute applies per token - agents doing bulk subscriber operations must implement backoff on 429 responses
- ⚠ Subscriber status 'unsubscribed' cannot be changed to 'active' via API - resubscribing a user requires the user to opt in again through a form
- ⚠ Webhook events do not include subscriber data inline - agents must make a follow-up API call to fetch subscriber details on webhook events
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for MailerLite API.
Scores are editorial opinions as of 2026-03-06.