Work with this as data
Every API here is available over the APIs.io API and to AI agents over MCP.
MCP server
One button, every client — Claude, Cursor, VS Code and the rest.
https://apis.io/mcp
Tools for apis
7 MCP tools reach this
find_apisBrowse and filter every API in the catalog.get_api_artifactsOne API's artifacts, grouped by type.get_openapiThe primary OpenAPI for this API.find_similar_apisAPIs that look like this one.apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.resolveTurn a domain, URL or GitHub org into the provider it belongs to.find_cohortsEvery scored population of providers in the catalog.
Call it yourself
curl for this page
This API
curl "https://apis.io/api/v1/apis/litmus-tests-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"Discovery needs no key. Ratings and market analysis are Pro.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.
A second provider on the same verified email joins the account you already have.
OpenAPI Specification
openapi: 3.2.0
info:
title: Litmus Legacy Previews Tests API
description: The Litmus Legacy Previews API provides REST endpoints for running email preview tests, spam filter tests, link-check tests, and code analysis against submitted email HTML. Tests are initiated by POSTing email content to the API and results are polled until rendering is complete. Authentication uses HTTP Basic Auth with Litmus account credentials.
version: 1.0.0
contact:
name: Litmus Support
url: https://www.litmus.com/support/
termsOfService: https://www.litmus.com/terms-of-service/
servers:
- url: https://previews-api.litmus.com/api/v1
description: Litmus Legacy Previews API Production Server
security:
- basicAuth: []
tags:
- name: Tests
description: Email test creation and management
paths:
/tests:
get:
operationId: listTests
summary: Litmus List tests
description: Returns a paginated list of all email tests run under the authenticated account. Each test entry includes the test type, creation timestamp, current status, and a link to the full test results.
tags:
- Tests
parameters:
- $ref: '#/components/parameters/pageParam'
- $ref: '#/components/parameters/perPageParam'
responses:
'200':
description: Paginated list of tests
content:
application/json:
schema:
$ref: '#/components/schemas/TestList'
'401':
description: Invalid credentials
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
post:
operationId: createTest
summary: Litmus Create a test
description: Creates a new email test by submitting email HTML, subject, and optional sender details. The test type (preview, spam, links) determines which checks are run. Returns the newly created test object with an ID for polling results.
tags:
- Tests
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/CreateTestRequest'
responses:
'201':
description: Test created successfully
content:
application/json:
schema:
$ref: '#/components/schemas/Test'
'400':
description: Invalid request body
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'401':
description: Invalid credentials
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
/tests/{testId}:
get:
operationId: getTest
summary: Litmus Get a test
description: Retrieves a specific email test by its numeric ID. Returns the test status and all available results. Poll this endpoint until the test status transitions to complete for all requested test types.
tags:
- Tests
parameters:
- $ref: '#/components/parameters/testIdParam'
responses:
'200':
description: Test retrieved successfully
content:
application/json:
schema:
$ref: '#/components/schemas/Test'
'401':
description: Invalid credentials
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'404':
description: Test not found
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
delete:
operationId: deleteTest
summary: Litmus Delete a test
description: Permanently deletes an email test and all associated results from the Litmus account. This action cannot be undone.
tags:
- Tests
parameters:
- $ref: '#/components/parameters/testIdParam'
responses:
'204':
description: Test deleted successfully
'401':
description: Invalid credentials
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'404':
description: Test not found
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
components:
parameters:
perPageParam:
name: per_page
in: query
description: Number of results per page
required: false
schema:
type: integer
minimum: 1
maximum: 100
default: 25
pageParam:
name: page
in: query
description: Page number for paginated results (1-based)
required: false
schema:
type: integer
minimum: 1
default: 1
testIdParam:
name: testId
in: path
description: Numeric identifier of the email test
required: true
schema:
type: integer
example: 12345678
schemas:
Error:
type: object
description: An API error response
required:
- message
properties:
message:
type: string
description: Human-readable error message
example: Authentication required
code:
type: string
description: Machine-readable error code
example: unauthorized
TestList:
type: object
description: Paginated list of email tests
properties:
tests:
type: array
description: Array of test summaries
items:
$ref: '#/components/schemas/Test'
total:
type: integer
description: Total number of tests in the account
example: 128
page:
type: integer
description: Current page number
example: 1
per_page:
type: integer
description: Number of tests per page
example: 25
CreateTestRequest:
type: object
description: Request body for creating an email test
required:
- html
properties:
html:
type: string
description: Full HTML source of the email to be tested
plain_text:
type: string
description: Optional plain text alternative of the email
subject:
type: string
description: Email subject line
maxLength: 998
from_address:
type: string
format: email
description: Sender email address used for spam filter testing
example: sender@example.com
from_name:
type: string
description: Sender display name used in spam filter context
example: My Company
clients:
type: array
description: Email client slugs to include in preview rendering
items:
type: string
example:
- GMAIL
- OL2019
run_spam_filter_tests:
type: boolean
description: Whether to run spam filter tests on the submitted email
default: false
run_link_check_tests:
type: boolean
description: Whether to run link reachability checks on URLs in the email HTML
default: false
Test:
type: object
description: An email test with status and result references
properties:
id:
type: integer
description: Unique numeric identifier for the test
example: 12345678
status:
type: string
description: Overall status of the test
enum:
- pending
- processing
- complete
- failed
example: complete
created_at:
type: string
format: date-time
description: Timestamp when the test was created
completed_at:
type: string
format: date-time
description: Timestamp when the test completed
subject:
type: string
description: Email subject that was tested
example: Welcome to Our Newsletter
from_address:
type: string
format: email
description: Sender address used in the test
example: sender@example.com
previews_requested:
type: boolean
description: Whether email client preview rendering was requested
spam_requested:
type: boolean
description: Whether spam filter testing was requested
links_requested:
type: boolean
description: Whether link checking was requested
securitySchemes:
basicAuth:
type: http
scheme: basic
description: HTTP Basic Auth using Litmus account username and password
externalDocs:
description: Litmus Legacy Previews API Documentation
url: https://docs.litmus.com/legacy-previews