Loops
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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Loops the way a machine reads it — 65 machine-readable artifacts across 12 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Loops scores 48.2/100 (developing), with a separate agent-readiness read of 61/100 (agent native). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Loops
Each block below is one kind of artifact we hold for Loops. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 12
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
Loops API key API
The API key API from Loops — 1 operation(s) for api key.
Loops Campaigns API
Create and manage email campaigns
Loops Components API
View email components
Loops Contact properties API
Manage contact properties
Loops Contacts API
Manage contacts in your audience
Loops Dedicated sending IPs API
View dedicated sending IP addresses
Loops Email messages API
Manage email message content for campaigns
Loops Events API
Trigger email sending with events
Loops Mailing lists API
View mailing lists
Loops Themes API
View email themes
Loops Transactional emails API
Send and view transactional emails
Loops Uploads API
Upload image assets
Scroll within the panel for all 12 ·
Open Collections 1
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Loops OpenAPI Spec
OPEN COLLECTIONFeatures 26
The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.
Notable capabilities this provider offers.
Scroll within the panel for all 26 ·
Security Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Integrations 23
Pre-built integrations with other platforms tell you where this provider already fits in a stack.
Pre-built integrations with other platforms and tools.
Stripe
Sync Stripe customers to your Loops audience and trigger automated emails on billing events.
Supabase
Send Supabase authentication emails (magic links, password reset, confirmations) through Loops.
Clerk
Send Clerk authentication emails through Loops.
Auth0
Route Auth0 authentication emails through Loops.
Auth.js
Send Auth.js authentication emails through Loops.
Better Auth
Route Better Auth transactional emails through Loops.
PostHog
Sync PostHog events and identified users into Loops contacts and workflows.
Segment
Sync Segment events and identified users into Loops.
RudderStack
Sync RudderStack events into Loops as event triggers.
Fivetran
Sync data into Loops via Fivetran connectors.
HubSpot
Sync HubSpot contacts to Loops.
Salesforce
Sync Salesforce contacts to Loops.
Attio
Sync Attio CRM contacts to Loops.
Clay
Push contacts from Clay into Loops.
Zapier
Connect Loops to 6,000+ apps via Zapier for contact sync, event triggers, and email sends.
Make
No-code automation flows that read from and write to Loops.
Integrately
No-code integration platform for connecting Loops to other tools.
Bubble
Send transactional email and sync contacts from Bubble no-code apps.
Framer
Capture form submissions in Framer sites and add them to Loops.
Webflow
Capture Webflow form submissions and add them to Loops contacts.
Emailify
Import custom MJML email templates from Emailify into Loops.
Email Love
Import MJML email templates from Email Love into Loops.
Incoming Webhooks
Receive arbitrary HTTP payloads and turn them into Loops events.
Scroll within the panel for all 23 ·
Resources
Every other property we hold for Loops — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 4
Portal, sign-up, and the first successful call
Documentation 4
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 2
Pagination, idempotency, versioning, errors, and events
Build 11
SDKs, sample code, and the tooling you integrate with
Scroll within the panel for all 11 ·
Access & Security 4
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Commercial 4
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/loops-so · machine-readable index on apis.io