Litmus website screenshot

Litmus

Email testing and analytics platform that allows developers and marketers to preview, test, and analyze email campaigns across multiple email clients and devices before sending.

Litmus publishes 6 APIs on the APIs.io network, including Analytics API, Campaigns API, Clients API, and 3 more. Tagged areas include Developer Tools, Email Testing, Marketing Tools, and Quality Assurance.

The Litmus catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Litmus’ developer surface includes authentication, documentation, getting-started guide, engineering blog, and 11 more developer resources.

🌐 Visit website 📡 Source on GitHub
36.5/100 thin ▬ flat Agent 26/100 agent aware Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0
AccessEnterprise
3 APIs
Developer ToolsEmail TestingMarketing ToolsQuality Assurance

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0
Composite quality — 36.5/100 · thin
Contract Quality 14.6 / 23
Developer Ergonomics 7.3 / 18
Access Clarity 4.3 / 18
Operational Transparency 1.2 / 12
Contract Governance 1.1 / 11
Discoverability 5.0 / 9
Create-or-Update Ergonomics 0.0 / 10
Agent readiness — 26/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
Documented Reversibility 0 / 6
MCP Server 0 / 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 0 / 6
Agent Skills 0 / 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 Well-Known Document 0 / 5
Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/litmus: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 6

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

Litmus Analytics API

Campaign engagement metrics and breakdowns

Litmus Campaigns API

Email campaign tracking and management

Litmus Clients API

Available email client configurations

Litmus Previews API

Email preview generation and management

Litmus Results API

Test result retrieval

Litmus Tests API

Email test creation and management

Open Collections 8

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

API Collection

OPEN COLLECTION

Litmus Email Analytics API

OPEN COLLECTION

Litmus Email Analytics Campaigns API

OPEN COLLECTION

Litmus Email Analytics Clients API

OPEN COLLECTION

Litmus Email Analytics API

OPEN COLLECTION

Litmus Instant API

OPEN COLLECTION

Litmus Email Analytics Results API

OPEN COLLECTION

Litmus Email Analytics Tests API

OPEN COLLECTION

Scroll for all 8

Pricing Plans 1

Published pricing tiers and plan structures.

Litmus Plans Pricing

7 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Litmus Rate Limits

4 limits

RATE LIMITS

FinOps 1

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

Litmus Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Litmus Context

7 classes · 46 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Litmus API Rules

6 rules · 5 warnings 1 info

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

Litmus Email Test

13 properties

JSON SCHEMA

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Litmus Authentication

http · 2 schemes

SECURITY

Litmus Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Litmus Trust Center

SOC 2, ISO 27001, GDPR

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Litmus Agentic Access

21 operations · 5 acting

21 operations · 5 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted
GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 JSONSchema
JSONSchema

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

JSONLD
JSONLD

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 5

Authentication, authorization, and security posture

TrustCenter
TrustCenter
 DomainSecurity
DomainSecurity
 Authentication
Authentication
 Authentication
Authentication
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

Community
Community

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: litmus
name: Litmus
description: Email testing and analytics platform that allows developers and marketers to preview, test, and analyze email
  campaigns across multiple email clients and devices before sending.
type: Index
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: enterprise
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Enterprise
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/litmus.png
tags:
- Developer Tools
- Email Testing
- Marketing Tools
- Quality Assurance
url: https://raw.githubusercontent.com/api-evangelist/litmus/refs/heads/main/apis.yml
created: '2025-01-01'
modified: '2026-05-19'
specificationVersion: '0.23'
apis:
- aid: litmus:litmus-analytics-api
  name: Litmus Analytics API
  description: Campaign engagement metrics and breakdowns
  humanURL: https://docs.litmus.com/instant
  baseURL: https://instant-api.litmus.com/v1
  tags:
  - Analytics
  properties:
  - type: OpenAPI
    url: openapi/litmus-analytics-api-openapi.yml
  - type: Documentation
    url: https://docs.litmus.com/instant
  - type: Authentication
    url: https://docs.litmus.com/oauth-integration-guide
  - type: Documentation
    url: https://docs.litmus.com/legacy-previews
  - type: Documentation
    url: https://docs.litmus.com/email-analytics
- aid: litmus:litmus-campaigns-api
  name: Litmus Campaigns API
  description: Email campaign tracking and management
  humanURL: https://docs.litmus.com/instant
  baseURL: https://instant-api.litmus.com/v1
  tags:
  - Campaigns
  properties:
  - type: OpenAPI
    url: openapi/litmus-campaigns-api-openapi.yml
  - type: Documentation
    url: https://docs.litmus.com/instant
  - type: Authentication
    url: https://docs.litmus.com/oauth-integration-guide
  - type: Documentation
    url: https://docs.litmus.com/legacy-previews
  - type: Documentation
    url: https://docs.litmus.com/email-analytics
- aid: litmus:litmus-clients-api
  name: Litmus Clients API
  description: Available email client configurations
  humanURL: https://docs.litmus.com/instant
  baseURL: https://instant-api.litmus.com/v1
  tags:
  - Clients
  properties:
  - type: OpenAPI
    url: openapi/litmus-clients-api-openapi.yml
  - type: Documentation
    url: https://docs.litmus.com/instant
  - type: Authentication
    url: https://docs.litmus.com/oauth-integration-guide
  - type: Documentation
    url: https://docs.litmus.com/legacy-previews
  - type: Documentation
    url: https://docs.litmus.com/email-analytics
- aid: litmus:litmus-previews-api
  name: Litmus Previews API
  description: Email preview generation and management
  humanURL: https://docs.litmus.com/instant
  baseURL: https://instant-api.litmus.com/v1
  tags:
  - Previews
  properties:
  - type: OpenAPI
    url: openapi/litmus-previews-api-openapi.yml
  - type: Documentation
    url: https://docs.litmus.com/instant
  - type: Authentication
    url: https://docs.litmus.com/oauth-integration-guide
  - type: Documentation
    url: https://docs.litmus.com/legacy-previews
  - type: Documentation
    url: https://docs.litmus.com/email-analytics
- aid: litmus:litmus-results-api
  name: Litmus Results API
  description: Test result retrieval
  humanURL: https://docs.litmus.com/instant
  baseURL: https://instant-api.litmus.com/v1
  tags:
  - Results
  properties:
  - type: OpenAPI
    url: openapi/litmus-results-api-openapi.yml
  - type: Documentation
    url: https://docs.litmus.com/instant
  - type: Authentication
    url: https://docs.litmus.com/oauth-integration-guide
  - type: Documentation
    url: https://docs.litmus.com/legacy-previews
  - type: Documentation
    url: https://docs.litmus.com/email-analytics
- aid: litmus:litmus-tests-api
  name: Litmus Tests API
  description: Email test creation and management
  humanURL: https://docs.litmus.com/instant
  baseURL: https://instant-api.litmus.com/v1
  tags:
  - Tests
  properties:
  - type: OpenAPI
    url: openapi/litmus-tests-api-openapi.yml
  - type: Documentation
    url: https://docs.litmus.com/instant
  - type: Authentication
    url: https://docs.litmus.com/oauth-integration-guide
  - type: Documentation
    url: https://docs.litmus.com/legacy-previews
  - type: Documentation
    url: https://docs.litmus.com/email-analytics
common:
- type: AgenticAccess
  url: agentic-access/litmus-agentic-access.yml
- type: TrustCenter
  url: security/litmus-trust-center.yml
- type: DomainSecurity
  url: security/litmus-domain-security.yml
- type: Authentication
  url: authentication/litmus-authentication.yml
- type: GitHubOrganization
  url: https://github.com/litmus
- type: LinkedIn
  url: https://www.linkedin.com/company/litmus-com
- url: https://www.litmus.com/
  type: Website
- url: https://docs.litmus.com/
  type: Documentation
- url: https://www.litmus.com/getting-started/test-your-email
  type: GettingStarted
- url: https://www.litmus.com/blog/
  type: Blog
- url: https://litmus.com/community
  type: Community
- url: https://docs.litmus.com/oauth-integration-guide
  type: Authentication
- url: https://docs.litmus.com/oauth/web-application-flow
  type: Authentication
- type: JSONSchema
  url: json-schema/litmus-email-test-schema.json
  name: Litmus Email Test JSON Schema
  description: JSON Schema for Litmus email test objects covering preview, spam filter, and link-check test requests and results.
- type: JSONLD
  url: json-ld/litmus-context.jsonld
  name: Litmus JSON-LD Context
  description: Linked data context mapping Litmus email test and campaign entities to standard vocabularies.
- type: Integrations
  url: https://www.litmus.com/integrations
integrations:
- name: Litmus
- name: Wistia video thumbnail
- name: Litmus page view feature example
- name: TrustRadius
- name: Booking.com
- name: Ford
- name: LendingTree
- name: publicis Worldwide
- name: Johnson and Johnson
- name: Target
- name: Cisco
- name: Sony
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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