listmonk

listmonk is a free and open-source, self-hosted newsletter and mailing-list manager built in Go with a Vue front end. Every feature in the admin UI is backed by a documented REST API on the self-hosted instance (Basic auth with an API user and token) covering subscribers, lists, campaigns, templates, media, CSV import, transactional messages, and bounces. There is no hosted SaaS - users run their own instance.

listmonk publishes 8 APIs on the APIs.io network, including Bounces API, Campaigns API, Import API, and 5 more. Tagged areas include Email, Newsletter, Mailing List, Marketing, and Transactional Email.

The listmonk catalog on APIs.io includes 1 event-driven AsyncAPI specification.

listmonk’s developer surface includes authentication, documentation, changelog, CLI, sandbox, API reference, getting-started guide, and 28 more developer resources.

🌐 Visit website 📡 Source on GitHub

52.5/100 developing ▬ flat Agent 28/100 agent aware Full breakdown ↓
scored 2026-08-25 · rubric v0.14.0

AccessFreemiumSelf serve⚡ Free to try

8 APIs

Email NewsletterMailing ListMarketing Transactional Email Campaigns SubscribersBounce HandlingOpen-Source Self-Hosted Go PostgreSQL

Kin Score

Kin Score How this is scored →
scored 2026-08-25 · rubric v0.14.0

Composite quality — 52.5/100 · developing

Contract Quality 11.8 / 21

Developer Ergonomics 12.0 / 17

Access Clarity 4.9 / 17

Operational Transparency 7.6 / 11

Contract Governance 1.7 / 10

Discoverability 6.3 / 9

Regulatory Posture 4.8 / 15

Agent readiness — 28/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Surface 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Telecommunications regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/listmonk: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 8

Individual APIs this provider publishes, each with its own machine-readable definition.

Open Collections 10

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Rate Limits 1

Documented rate limits and quota policies.

Listmonk Rate Limits

4 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

Sandbox

DeveloperPortal

GettingStarted

Demo

Documentation 4

Reference material describing how the API behaves

Documentation

OpenAPI

AsyncAPI

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Webhooks

Conventions

ErrorCatalog

DataModel

Conformance

Lifecycle

Build 5

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

ToolCrosswalk

CLI

SourceCode

Access & Security 4

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

VulnerabilityDisclosure

VulnerabilityDisclosure

Security

Security

Operate 3

Status, limits, changes, and where to get help

RateLimits

RateLimits

ChangeLog

ChangeLog

Support

Support

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

License

License

Company 2

The organization behind the API

LinkedIn

Website

Website

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: listmonk
url: https://raw.githubusercontent.com/api-evangelist/listmonk/refs/heads/main/apis.yml
name: listmonk
kind: company
description: listmonk is a free and open-source, self-hosted newsletter and mailing-list manager built in Go with a Vue front
  end. Every feature in the admin UI is backed by a documented REST API on the self-hosted instance (Basic auth with an API
  user and token) covering subscribers, lists, campaigns, templates, media, CSV import, transactional messages, and bounces.
  There is no hosted SaaS - users run their own instance.
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/listmonk.png
tags:
- Email
- Newsletter
- Mailing List
- Marketing
- Transactional Email
- Campaigns
- Subscribers
- Bounce Handling
- Open-Source
- Self-Hosted
- Go
- PostgreSQL
tags_raw:
- Email
- Newsletter
- Mailing List
- Marketing
- Transactional Email
- Campaigns
- Subscribers
- Bounce Handling
- Open Source
- Self-Hosted
- Go
- PostgreSQL
created: '2026-06-25'
modified: '2026-08-13'
specificationVersion: '0.23'
apis:
- aid: listmonk:listmonk-bounces-api
  name: listmonk Bounces API
  description: The Bounces API from listmonk — 2 operation(s) for bounces.
  humanURL: https://listmonk.app/docs/apis/bounces/
  baseURL: https://{listmonk_host}/api
  tags:
  - Bounces
  properties:
  - type: OpenAPI
    url: openapi/listmonk-bounces-api-openapi.yml
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
  - type: Documentation
    url: https://listmonk.app/docs/apis/bounces/
- aid: listmonk:listmonk-campaigns-api
  name: listmonk Campaigns API
  description: The Campaigns API from listmonk — 8 operation(s) for campaigns.
  humanURL: https://listmonk.app/docs/apis/campaigns/
  baseURL: https://{listmonk_host}/api
  tags:
  - Campaigns
  properties:
  - type: OpenAPI
    url: openapi/listmonk-campaigns-api-openapi.yml
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
  - type: Documentation
    url: https://listmonk.app/docs/apis/campaigns/
- aid: listmonk:listmonk-import-api
  name: listmonk Import API
  description: The Import API from listmonk — 2 operation(s) for import.
  humanURL: https://listmonk.app/docs/apis/import/
  baseURL: https://{listmonk_host}/api
  tags:
  - Import
  properties:
  - type: OpenAPI
    url: openapi/listmonk-import-api-openapi.yml
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
  - type: Documentation
    url: https://listmonk.app/docs/apis/import/
- aid: listmonk:listmonk-lists-api
  name: listmonk Lists API
  description: The Lists API from listmonk — 3 operation(s) for lists.
  humanURL: https://listmonk.app/docs/apis/lists/
  baseURL: https://{listmonk_host}/api
  tags:
  - List
  tags_raw:
  - Lists
  properties:
  - type: OpenAPI
    url: openapi/listmonk-lists-api-openapi.yml
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
  - type: Documentation
    url: https://listmonk.app/docs/apis/lists/
- aid: listmonk:listmonk-media-api
  name: listmonk Media API
  description: The Media API from listmonk — 2 operation(s) for media.
  humanURL: https://listmonk.app/docs/apis/media/
  baseURL: https://{listmonk_host}/api
  tags:
  - Media
  properties:
  - type: OpenAPI
    url: openapi/listmonk-media-api-openapi.yml
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
  - type: Documentation
    url: https://listmonk.app/docs/apis/media/
- aid: listmonk:listmonk-subscribers-api
  name: listmonk Subscribers API
  description: The Subscribers API from listmonk — 10 operation(s) for subscribers.
  humanURL: https://listmonk.app/docs/apis/subscribers/
  baseURL: https://{listmonk_host}/api
  tags:
  - Subscribers
  properties:
  - type: OpenAPI
    url: openapi/listmonk-subscribers-api-openapi.yml
  - type: Documentation
    url: https://listmonk.app/docs/apis/subscribers/
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
- aid: listmonk:listmonk-templates-api
  name: listmonk Templates API
  description: The Templates API from listmonk — 5 operation(s) for templates.
  humanURL: https://listmonk.app/docs/apis/templates/
  baseURL: https://{listmonk_host}/api
  tags:
  - Templates
  properties:
  - type: OpenAPI
    url: openapi/listmonk-templates-api-openapi.yml
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
  - type: Documentation
    url: https://listmonk.app/docs/apis/templates/
- aid: listmonk:listmonk-transactional-api
  name: listmonk Transactional API
  description: The Transactional API from listmonk — 1 operation(s) for transactional.
  humanURL: https://listmonk.app/docs/apis/transactional/
  baseURL: https://{listmonk_host}/api
  tags:
  - Transactional
  properties:
  - type: OpenAPI
    url: openapi/listmonk-transactional-api-openapi.yml
  - type: APIReference
    url: https://listmonk.app/docs/apis/apis/
  - type: Documentation
    url: https://listmonk.app/docs/apis/transactional/
common:
- type: AgenticAccess
  url: agentic-access/listmonk-agentic-access.yml
- type: DomainSecurity
  url: security/listmonk-domain-security.yml
- type: Authentication
  url: authentication/listmonk-authentication.yml
- type: GitHubOrganization
  url: https://github.com/knadh/listmonk
- type: LinkedIn
  url: https://www.linkedin.com/in/knadh
- type: Website
  url: https://listmonk.app
- type: Documentation
  url: https://listmonk.app/docs/apis/apis/
- type: Plans
  url: plans/listmonk-plans-pricing.yml
- type: RateLimits
  url: rate-limits/listmonk-rate-limits.yml
- type: FinOps
  url: finops/listmonk-finops.yml
- type: OpenAPI
  url: openapi/_original/listmonk-collections-openapi.yml
- type: Overlay
  url: overlays/listmonk-collections-overlay.yaml
- type: Packages
  url: packages/listmonk-packages.yml
- type: LLMsTxt
  url: llms/listmonk-llms.txt
- type: AgentSkill
  url: skills/_index.yml
- type: ToolCrosswalk
  url: mcp/listmonk-tool-crosswalk.yml
- type: AsyncAPI
  url: asyncapi/listmonk-bounce-webhooks-asyncapi.yml
- type: Webhooks
  url: asyncapi/listmonk-bounce-webhooks-asyncapi.yml
- type: Conventions
  url: conventions/listmonk-conventions.yml
- type: ErrorCatalog
  url: errors/listmonk-problem-types.yml
- type: DataModel
  url: data-model/listmonk-data-model.yml
- type: Conformance
  url: conformance/listmonk-conformance.yml
- type: Lifecycle
  url: lifecycle/listmonk-lifecycle.yml
- type: ChangeLog
  url: changelog/listmonk-changelog.yml
- type: CLI
  url: cli/listmonk-cli.yml
- type: Sandbox
  url: sandbox/listmonk-sandbox.yml
- type: VulnerabilityDisclosure
  url: security/listmonk-vulnerability-disclosure.yml
- type: Security
  url: https://listmonk.app/docs/security-reports/
- type: DeveloperPortal
  url: https://listmonk.app/docs/
- type: APIReference
  url: https://listmonk.app/docs/apis/apis/
- type: GettingStarted
  url: https://listmonk.app/docs/installation/
- type: Support
  url: https://github.com/knadh/listmonk/issues
- type: SourceCode
  url: https://github.com/knadh/listmonk
- type: License
  url: https://github.com/knadh/listmonk/blob/master/LICENSE
- type: Demo
  url: https://demo.listmonk.app/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 18
  pass: local-v1

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