aid: loops-so
url: https://raw.githubusercontent.com/api-evangelist/loops-so/refs/heads/main/apis.yml
apis:
- aid: loops-so:loops-api
  name: Loops API
  tags:
  - Email
  - Marketing
  - Transactional
  - Contacts
  - Campaigns
  - Events
  - SaaS
  humanURL: https://loops.so/docs/api-reference/intro
  properties:
  - url: https://loops.so/docs/api-reference/intro
    type: Documentation
  - url: https://app.loops.so/openapi.yaml
    type: OpenAPI
  - url: https://app.loops.so/openapi.json
    type: OpenAPI
  - url: openapi/loops-openapi.yml
    type: OpenAPI
  description: The Loops API is a single REST API exposing every Loops resource —
    contacts, contact properties, mailing lists, events, campaigns, email messages,
    themes, components, transactional sends, uploads, suppressions, and dedicated
    sending IPs. Base URL is https://app.loops.so/api/v1. Bearer-token authentication
    with API keys generated in Settings → API. Defaults to 10 requests/second per
    team with x-ratelimit-limit and x-ratelimit-remaining response headers; returns
    HTTP 429 when exceeded. OpenAPI 3.1 spec published at app.loops.so/openapi.yaml.
name: Loops
tags:
- Email
- Marketing Email
- Transactional Email
- Email Automation
- Email Campaigns
- Email Workflows
- Contacts
- Audience Management
- Events
- Webhooks
- SaaS
- Developer Tools
kind: contract
image: https://kinlane-productions2.s3.amazonaws.com/apis-json/apis-json-logo.jpg
access: 3rd-Party
common:
- url: https://loops.so
  type: Portal
- url: https://loops.so/docs
  name: Loops Docs
  type: Documentation
- url: https://loops.so/docs/api-reference/intro
  name: API Reference
  type: Documentation
- url: https://app.loops.so/openapi.yaml
  name: OpenAPI YAML
  type: OpenAPI
- url: https://app.loops.so/openapi.json
  name: OpenAPI JSON
  type: OpenAPI
- url: https://loops.so/docs/quickstart
  name: Quickstart
  type: GettingStarted
- url: https://loops.so/docs/webhooks
  name: Webhooks
  type: Webhooks
- url: https://loops.so/docs/integrations
  name: Integrations
  type: Integrations
- url: https://loops.so/pricing
  name: Pricing
  type: Pricing
- url: https://loops.so/blog
  type: Blog
- url: https://loops.so/changelog
  type: ChangeLog
- url: https://loops.so/legal/terms
  type: TermsOfService
- url: https://loops.so/legal/privacy
  type: PrivacyPolicy
- url: https://loops.so/legal/security
  type: Security
- url: https://app.loops.so/register
  name: Sign Up
  type: SignUp
- url: https://app.loops.so/login
  name: Sign In
  type: SignIn
- url: https://twitter.com/loops_so
  type: Twitter
- url: https://www.linkedin.com/company/loops-so
  type: LinkedIn
- url: https://github.com/loops-so
  name: Loops GitHub
  type: GitHubOrganization
- url: https://github.com/loops-so/loops-js
  name: Loops JavaScript SDK
  type: SDK
- url: https://github.com/loops-so/loops-nuxt
  name: Loops Nuxt SDK
  type: SDK
- url: https://github.com/loops-so/loops-php
  name: Loops PHP SDK
  type: SDK
- url: https://github.com/loops-so/loops-rb
  name: Loops Ruby SDK
  type: SDK
- url: https://github.com/loops-so/loops-go
  name: Loops Go SDK
  type: SDK
- url: https://github.com/loops-so/cli
  name: Loops CLI
  type: Tool
- url: https://github.com/loops-so/homebrew-tap
  name: Loops Homebrew Tap
  type: Tool
- url: https://github.com/loops-so/skills
  name: Loops Skills for Claude Code
  type: Tool
- url: https://github.com/loops-so/loops-nextjs
  name: Loops Next.js Example
  type: CodeExamples
- url: https://www.npmjs.com/package/loops
  name: loops on npm
  type: Package
- url: https://loops.so/pricing
  data:
  - id: free
    name: Free
    entries:
    - geo: US
      unit: 1
      label: User
      limit: 1
      price: Free
      metric: user
      timeFrame: month
      description: Free tier — no credit card required. Loops branding shown at the
        bottom of emails.
    elements:
    - name: Up to 1,000 subscribed contacts
    - name: Up to 4,000 sends per month (enough for weekly emails)
    - name: All features included
    - name: Transactional email at no extra charge
    - name: Unlimited team seats
    - name: Loops branding at the bottom of every email
    description: Free to start. No credit card required.
  - id: paid
    name: Paid
    entries:
    - geo: US
      unit: 1
      label: User
      limit: 1
      price: Call
      metric: user
      timeFrame: month
      description: Paid plans remove send limits and Loops branding. Pricing scales
        by audience size and contact tier.
    elements:
    - name: Remove send limits
    - name: Remove Loops branding from emails
    - name: All features included
    - name: Transactional email at no extra charge
    - name: Unlimited team seats — never charged per seat
    - name: Never charged per send
    description: For teams sending beyond the free-tier limits.
  - id: custom
    name: Custom
    entries:
    - geo: US
      unit: 1
      label: User
      limit: 1
      price: Call
      metric: user
      timeFrame: month
      description: Custom plans for high-volume senders and enterprise.
    elements:
    - name: Custom contact and send volumes
    - name: Dedicated sending IPs
    - name: Custom plan terms
    description: Contact Loops for custom plans.
  name: Plans
  type: Plans
- type: Authentication
  data:
  - name: Bearer Token
    description: API keys are generated in the Loops dashboard under Settings → API
      and passed via the Authorization header as Bearer tokens. Test keys with GET
      /api-key.
- type: RateLimits
  data:
  - name: Default API rate limit
    description: 10 requests per second per team. Responses include x-ratelimit-limit
      and x-ratelimit-remaining headers; HTTP 429 returned when exceeded.
  - name: Webhook delivery rate limit
    description: Webhooks deliver at a maximum of 10 events per second; excess events
      are queued for subsequent delivery.
- type: Webhooks
  data:
  - name: Webhook event categories
    description: Contact events (contact.created, contact.unsubscribed, contact.deleted,
      contact.mailingList.subscribed/unsubscribed); email send events (campaign.email.sent,
      loop.email.sent, transactional.email.sent); email engagement (email.delivered,
      email.opened, email.clicked, email.softBounced, email.hardBounced, email.unsubscribed,
      email.resubscribed, email.spamReported); and testing.testEvent.
  - name: Webhook signing
    description: Each webhook carries Webhook-Id, Webhook-Timestamp, and Webhook-Signature
      (HMAC-SHA256) headers. Verify by recomputing the signature from event ID, timestamp,
      and raw body using the signing secret saved during webhook setup.
  - name: Webhook schema version
    description: Webhooks include webhookSchemaVersion 1.0.0, eventName, and eventTime
      (unix seconds). 30 days of delivery history is retained.
- type: Integrations
  data:
  - name: Stripe
    description: Sync Stripe customers to your Loops audience and trigger automated
      emails on billing events.
  - name: Supabase
    description: Send Supabase authentication emails (magic links, password reset,
      confirmations) through Loops.
  - name: Clerk
    description: Send Clerk authentication emails through Loops.
  - name: Auth0
    description: Route Auth0 authentication emails through Loops.
  - name: Auth.js
    description: Send Auth.js authentication emails through Loops.
  - name: Better Auth
    description: Route Better Auth transactional emails through Loops.
  - name: PostHog
    description: Sync PostHog events and identified users into Loops contacts and
      workflows.
  - name: Segment
    description: Sync Segment events and identified users into Loops.
  - name: RudderStack
    description: Sync RudderStack events into Loops as event triggers.
  - name: Fivetran
    description: Sync data into Loops via Fivetran connectors.
  - name: HubSpot
    description: Sync HubSpot contacts to Loops.
  - name: Salesforce
    description: Sync Salesforce contacts to Loops.
  - name: Attio
    description: Sync Attio CRM contacts to Loops.
  - name: Clay
    description: Push contacts from Clay into Loops.
  - name: Zapier
    description: Connect Loops to 6,000+ apps via Zapier for contact sync, event triggers,
      and email sends.
  - name: Make
    description: No-code automation flows that read from and write to Loops.
  - name: Integrately
    description: No-code integration platform for connecting Loops to other tools.
  - name: Bubble
    description: Send transactional email and sync contacts from Bubble no-code apps.
  - name: Framer
    description: Capture form submissions in Framer sites and add them to Loops.
  - name: Webflow
    description: Capture Webflow form submissions and add them to Loops contacts.
  - name: Emailify
    description: Import custom MJML email templates from Emailify into Loops.
  - name: Email Love
    description: Import MJML email templates from Email Love into Loops.
  - name: Incoming Webhooks
    description: Receive arbitrary HTTP payloads and turn them into Loops events.
- type: Features
  data:
  - Unified platform for product, marketing, and transactional email built for software
    companies
  - Single REST API (OpenAPI 3.1 published at app.loops.so/openapi.yaml) covering
    contacts, properties, mailing lists, events, campaigns, email messages, themes,
    components, transactional, uploads, suppressions, and dedicated sending IPs
  - Bearer-token API key authentication with a GET /api-key test endpoint
  - 10 requests/second per team baseline rate limit with x-ratelimit-* response headers
  - Contacts API — create, update, find, delete; manage suppression status
  - Contact properties API — create custom properties and list the full property catalog
  - Mailing lists API — list mailing lists and manage list membership via contact
    updates
  - Events API — POST /events/send to trigger loops (workflows) and personalize
    content
  - Campaigns API — full CRUD plus list, with separate endpoints for the email message
    body
  - Email message API — fetch and update the content of an individual email message
    inside a campaign
  - Themes and components API — read reusable themes and shared components used across
    emails
  - Transactional email API — send transactional emails with template variables, file
    attachments, and headers; list transactional sends
  - Uploads API — create and complete file uploads for use in transactional attachments
  - Dedicated sending IPs API — list dedicated IPs assigned to your account
  - Webhook system with HMAC-SHA256 signing, 30 days of delivery history, contact
    + email + send + testing events, schema version 1.0.0
  - Lifecycle workflows ("loops") with triggers, timers, branching, and conditional
    logic
  - Saved segments built from contact properties and engagement data
  - A/B testing for campaigns
  - Email design editor optimized for major email clients
  - Analytics for conversion, opens, clicks, bounces, and unsubscribes
  - Official SDKs for JavaScript/TypeScript, Nuxt, PHP, Ruby, and Go; community SDKs
    for Laravel and Rails
  - Official `loops` CLI (Go) with Homebrew tap distribution
  - Official Claude Code Skills repository for the Loops API and CLI
  - 25+ integrations across Stripe, Supabase, Clerk, Auth0, Auth.js, Better Auth,
    PostHog, Segment, RudderStack, Fivetran, HubSpot, Salesforce, Attio, Clay, Zapier,
    Make, Integrately, Bubble, Framer, Webflow, Emailify, and Email Love
  - Transactional email included at no extra charge on every plan
  - Unlimited team seats — never billed per seat or per send
  sources:
  - https://loops.so
  - https://loops.so/docs/api-reference/intro
  - https://app.loops.so/openapi.yaml
  - https://loops.so/docs/webhooks
  - https://loops.so/docs/integrations
  - https://loops.so/pricing
  - https://github.com/loops-so
  updated: '2026-05-25'
created: '2026-05-25T00:00:00.000Z'
modified: '2026-05-25'
position: Consuming
description: Loops is a modern email platform purpose-built for software companies,
  combining product, marketing, and transactional email behind a single REST API
  and a single audience. Contacts, contact properties, mailing lists, events, segments,
  campaigns, email messages, themes, components, uploads, transactional sends, and
  dedicated sending IPs are all first-class API resources, with an OpenAPI 3.1 spec
  published at app.loops.so/openapi.yaml. Lifecycle workflows ("loops") use the
  Events API as their trigger, an HMAC-SHA256-signed webhook stream broadcasts every
  contact and email event for real-time integrations, and official SDKs ship for
  JavaScript, Nuxt, PHP, Ruby, and Go alongside an official Go-based CLI. Transactional
  email is included on every plan, team seats are unlimited, and a generous free
  tier covers 1,000 contacts and 4,000 sends per month — making Loops a Tier-1
  developer-first email service for SaaS teams from waitlist to IPO.
maintainers:
- FN: Kin Lane
  email: info@apievangelist.com
  X: apievangelist
  url: https://apievangelist.com
specificationVersion: '0.16'