REST endpoints
Marketing tools with
a real public API.
Every tool I track that publishes a REST API you can actually read. Hook it into your warehouse, dashboards, scheduled jobs, or agent stack. Auth, SDK language, and OpenAPI spec verified at source, not guessed.
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Need a specific API?
Type a tool name or a category. Jump straight to auth, SDK languages, rate limits, and which plan unlocks the API.
Why it matters
What to look for in a marketing API
Three things separate a usable API from a frustrating one. An OpenAPI / Swagger spec means you can auto-generate typed clients. Official SDKs save auth boilerplate. Webhooks mean you can react to events instead of polling on a cron.
Each card shows these signals at a glance. Click into a tool for pricing per tier, rate limits, and a quickstart snippet.
My shortlist
Highest Agent-Fit Scores
The APIs that behave well under an agent. Scored on auth depth, action coverage, rate-limit honesty, and how predictable the responses are. The ones I'd wire into a Claude or LangChain stack first.
Leadpages
Landing Page Builder
Drag-and-drop landing page builder with 200+ templates and strong conversion optimization tools
Loops
Email Marketing
API-first email platform designed specifically for SaaS teams and product-focused businesses
Resend
Email Marketing
Developer-first email API
Mailjet
Email Marketing
Email platform combining marketing campaigns with developer APIs and volume-based pricing
Profound
AI Search Visibility
AI search analytics & brand visibility
Sequenzy
Email Marketing
AI-native email marketing with a first-party MCP server
Spec-published
APIs with an OpenAPI Spec
These publish a machine-readable spec. Drop the URL into Postman, generate a typed Node / Python / Go client, skip the docs-page wrangling.
Leadpages
Landing Page Builder
Drag-and-drop landing page builder with 200+ templates and strong conversion optimization tools
Loops
Email Marketing
API-first email platform designed specifically for SaaS teams and product-focused businesses
Resend
Email Marketing
Developer-first email API
Rankability
Content Optimization
AI-powered SEO tool for content optimization and AI search tracking built for agencies.
SearchApi
SEO API
SERP & search data API
Mailchimp
Email Marketing
Popular email marketing platform that has become overpriced with declining value for most users
Publer
Social Media Automation
Affordable social scheduler with AI assist, bulk uploads, and recycling for evergreen content.
Builderall
All-in-One Marketing
All-in-one marketing platform with 25+ tools including website builder, email marketing, and course creation
GoHighLevel
All-in-One Marketing
All-in-one CRM and marketing platform designed for agencies. Replaces multiple tools but has a steep learning curve.
ValueSERP
SEO API
Google SERP API
LinkResearchTools
SEO Software
Backlink analysis & audits
Podia
Online Course Platform
All-in-one creator platform with website builder, course hosting, and email marketing at budget-friendly prices
SendGrid
Email Marketing
Marketing + transactional email API
Flodesk
Email Marketing
Design-focused email marketing platform with beautiful templates and sales funnels for creators
GrowthBar
AI Content SEO
AI writing & SEO
Instapage
Landing Page Builder
Drag-and-drop landing page builder with A/B testing and personalization for marketers
LanderLab
Landing Page Builder
AI-powered landing page builder specialized for performance marketing with proven templates and native integrations
Zenserp
SEO Software
SERP scraping API
Docs-only
Other APIs
Public API documented, but no OpenAPI spec detected. You write the wrappers yourself. Still usable, just more legwork.
Mailjet
Email Marketing
Email platform combining marketing campaigns with developer APIs and volume-based pricing
Profound
AI Search Visibility
AI search analytics & brand visibility
Sequenzy
Email Marketing
AI-native email marketing with a first-party MCP server
ActiveCampaign
Email Marketing
AI-powered email marketing and automation platform for businesses serious about personalized campaigns
Ahrefs
SEO Software
Comprehensive SEO platform with powerful backlink analysis and keyword research tools
DataForSEO
SEO API
API-first SEO data platform for developers building SEO tools and software solutions
Kit
Email Marketing
Creator-focused email marketing platform with powerful automations and integrated monetization tools
Klaviyo
Ecommerce Marketing
AI-powered marketing automation platform for ecommerce businesses with unified customer data and omnichannel campaigns
Omnisend
Ecommerce Marketing
Ecommerce-focused email and SMS marketing platform with powerful automation and 160+ integrations
AWeber
Email Marketing
Established email marketing platform with 27 years of experience, AI features, and reliable fundamentals
Ayrshare
Social Media Automation
Social media API for SaaS builders: post and read analytics across 11+ networks via one REST API.
Blotato
Social Media Automation
AI-native content remixer and multi-platform publisher built around viral-post workflows.
Bolta.ai
Social Media Automation
AI co-pilot for short-form video: turn long videos into platform-ready clips with hooks and captions.
Bright Data
SEO Software
Web data & SERP API
Buffer
Social Media Automation
Veteran social scheduler with a clean UI and a generous free plan for solopreneurs.
Clickfunnels
All-in-One Marketing
All-in-one marketing platform for building sales funnels, hosting courses, and managing customers
Crawly
SEO Software
Free native macOS SEO crawler with built-in MCP server.
Frase
AI Content SEO
AI-powered SEO content platform with research, optimization, and AI search visibility tracking
HubSpot
All-in-One Marketing
All-in-one CRM and marketing platform with generous free tools but steep paid plan pricing jumps
Lumar
SEO Software
Enterprise SEO crawler
MailerLite
Email Marketing
Affordable email marketing with surprisingly powerful features and stellar support
Mailgun
Email Marketing
Developer email API
Peec AI
AI Search Visibility
AI brand visibility tracking
Postmark
Email Marketing
Transactional email with top deliverability
SE Ranking
SEO Software
Complete SEO platform with AI visibility tracking, rank monitoring, and competitive research tools.
Screaming Frog
SEO Software
Desktop SEO crawler for technical audits with unlimited crawling for $259/year
Semrush
SEO Software
Complete SEO platform with AI search tracking, keyword research, competitor analysis, and content optimization tools.
SerpApi
SEO API
Real-time SERP API
Serpstat
SEO Software
All-in-one SEO platform
SimilarWeb
SEO Software
Digital market intelligence platform for traffic analysis and competitive research.
Thinkific
Online Course Platform
Course platform with drag-and-drop builder, communities, and commerce tools for educators and businesses
Unbounce
Landing Page Builder
Drag-and-drop landing page builder with A/B testing and AI optimization for marketers and agencies
Unipile
Social Media Automation
Messaging API that unifies LinkedIn, WhatsApp, Instagram, Telegram DMs into a single integration.
Zernio
Social Media Automation
AI agent for social media management, scheduling, and DMs across 10+ platforms.
beehiiv
Email Marketing
All-in-one newsletter platform with built-in website builder and monetization tools for creators
Customer.io
Email Marketing
Advanced customer engagement platform with AI agents, starting at $100/month for data-driven teams
Drip
Ecommerce Marketing
Email marketing automation platform built for ecommerce brands with advanced segmentation and workflows.
Encharge
Email Marketing
SaaS marketing automation
Ghost
Newsletter Platform
Publishing platform with built-in newsletter and membership monetization. No platform fees on revenue.
Kajabi
All-in-One Marketing
All-in-one platform for course creators, coaches, and experts to build, market, and sell knowledge products
LowFruits
SEO Software
SERP-focused keyword research tool that analyzes competition weaknesses beyond traditional KD scores
Mangools
SEO Software
User-friendly SEO suite with excellent keyword research tools and competitive pricing for agencies
NeuronWriter
AI Content SEO
SERP content optimization
OnCrawl
SEO Software
SEO crawler & log analysis
Sistrix
SEO Software
SEO visibility & toolbox
Zoho Campaigns
Email Marketing
Email marketing platform with SMS and deep Zoho ecosystem integration for business users
Botify
SEO Software
Enterprise SEO platform with AI search optimization and custom pricing for large-scale sites
Braze
Email Marketing
Enterprise customer engagement
Brevo
Email Marketing
All-in-one email marketing platform with SMS, automation, and AI features at competitive prices
Buttondown
Newsletter Platform
Minimal newsletter platform with markdown support and privacy-first approach for content creators
Constant Contact
Email Marketing
Established email marketing platform with simple tools but outdated features at $12-80/month
GetResponse
Email Marketing
AI-powered email marketing platform with automation, landing pages, and webinars starting at $19/month
Keap
All-in-One Marketing
All-in-one CRM and marketing automation platform for small businesses ready to scale operations
Keywords Everywhere
SEO Software
Keyword metrics API
Majestic
SEO Software
Backlink index & link data
Ortto
Email Marketing
CDP + journey automation
Plunk
Email Marketing
Open-source email platform
Sender
Email Marketing
Affordable email marketing platform with generous free plan and multichannel automation
SpyFu
SEO API
Competitive intelligence tool for Google Ads and SEO research with 18+ years of historical data
SurferSEO
AI Content SEO
AI-powered SEO platform for content optimization across Google and AI search engines
Systeme.io
All-in-One Marketing
Complete marketing platform with sales funnels, email marketing, courses, and more at budget-friendly prices
Wincher
SEO Software
Keyword rank tracking
Benchmark Email
Email Marketing
Simple email builder with AI tools but no automation or A/B testing
Conductor
SEO Software
Enterprise SEO & content
MailerSend
Email Marketing
Transactional + bulk email API
Outranking
AI Content SEO
AI SEO writing
AccuRanker
SEO Software
Fast keyword rank tracker
Advanced Web Ranking
SEO Software
Rank tracking & reporting
AnswerThePublic
SEO Software
Visual keyword research tool that maps out questions people actually search for online
Athena HQ
AI Search Visibility
GEO analytics platform
Authoritas
SEO Software
SEO platform & SERP API
BrightEdge
SEO Software
Enterprise SEO platform
Bundle.social
Social Media Automation
Social media API for developers: one endpoint to publish to TikTok, Instagram, LinkedIn, YouTube, X, Pinterest.
Campaign Monitor
Email Marketing
Elegant email marketing platform with powerful automation and beautiful templates for growing businesses
EmailOctopus
Email Marketing
Budget-friendly email marketing platform with a generous free plan and simple automation for small businesses.
Iterable
Email Marketing
Enterprise cross-channel marketing
JetOctopus
SEO Software
SEO crawler & log analyzer
Kartra
All-in-One Marketing
True all-in-one marketing platform with advanced funnels, email automation, and membership hosting
LearnWorlds
Online Course Platform
AI-powered course platform with interactive video tools and white-label branding at premium prices
Moosend
Email Marketing
Email marketing platform with powerful automation, landing pages, and forms at budget-friendly pricing
Moz Pro
SEO Software
Veteran SEO platform with 20+ years of experience and comprehensive toolkit for rankings, traffic, and optimization
Nightwatch
SEO Software
Rank tracking & SEO analytics
Otterly.ai
AI Search Visibility
AI search visibility monitoring
Oxylabs
SEO API
SERP scraper & proxies
Perspective Funnels
Landing Page Builder
Mobile-first funnel builder with interactive features and high conversion templates for modern marketers.
Postiz
Social Media Automation
Open-source social media scheduler with AI assist; self-host or use the cloud version.
Ryte
SEO Software
Website quality & technical SEO
Scrunch AI
AI Search Visibility
AI answer-engine visibility
Seobility
SEO Software
User-friendly SEO platform with website auditing, keyword tracking, and backlink analysis for all skill levels.
Teachable
Online Course Platform
Course platform with AI tools, global payments, and mobile apps for serious creators scaling worldwide
Wishpond
All-in-One Marketing
All-in-one marketing platform with landing pages, email marketing, and lead generation tools
seoClarity
SEO Software
Enterprise SEO platform
Landingi
Landing Page Builder
Landing page builder with AI assistance, A/B testing, and 170+ integrations for marketers
Selzy
Email Marketing
Budget email marketing with flexible pricing and strong support, but basic automation features
Prefer an MCP server?
If you're wiring tools into Claude, Cursor, or Codex, an MCP server is usually less code than the REST API. The /mcp directory lists every tool that ships one.
See the MCP directory