Loops

Loops is an email platform built for software companies, combining marketing campaigns, product and lifecycle automation, and transactional email on one contact model. Its REST API v1 exposes 64 operations across contacts, contact properties, mailing lists, audience segments, events and event patterns, campaigns, transactional emails, email messages authored in its own LMX markup, themes, components, uploads and workflow graphs, plus a 17-event signed webhook surface. Loops publishes its OpenAPI 3.1 document openly, ships first-party SDKs for JavaScript, Go, PHP, Ruby and Nuxt, a Go CLI, four versioned Agent Skills, and a hosted OAuth-protected MCP server at mcp.loops.so. Pricing is based on stored subscribed contacts rather than send volume, with a permanent free tier. The operating company is Astrodon Corporation.

Loops publishes 21 API contracts indexed on the APIs.io network, including API key API, Audience segments API, Campaign groups API, and 18 more. Tagged areas include Email, Email API, Marketing Automation, Transactional Email, and Lifecycle Email.

The Loops catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.

Loops’ developer surface includes authentication, code examples, CLI, changelog, documentation, API reference, getting-started guide, and 39 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

76.6/100 exemplar ▬ flat Agent 65/100 agent native Front door AI 3/6 light Heartbeat 44/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract 1 MCP Servers 4 Agent Skills

Email Email API Marketing Automation Transactional EmailLifecycle EmailWebhook Software-as-a-Service Communications Developer Tools MCP Agents Campaigns

What this lets a business do 3

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

Customer Relationship Management

BC-420

Audience segmentsContact propertiesContacts

POST /v1/contacts/create GET /v1/contacts/find POST /v1/audience-segments POST /v1/contacts/properties

Marketing Management

BC-400

CampaignsWorkflow nodesWorkflows

POST /v1/campaigns POST /v1/workflows POST /v1/workflows/{workflowId} POST /v1/workflows/{workflowId}/mailing-list

Application Communications

AE-150

Email Messages

POST /v1/email-messages/{emailMessageId} POST /v1/email-messages/{emailMessageId}/preview

What people ask Loops 18

The questions people put to an LLM, and the jobs they hand an agent, that Loops's APIs answer — each one linked to the operation that does it. Generated by API Evangelist

Loops Transactional emails API Send a transactional email “How do I send a password reset or receipt email to one person?” List published transactional emails “Which transactional emails are published and ready to send?” List all transactional emails incl. drafts “What transactional emails exist, including ones not yet published?” Create a transactional email “How do I set up a new transactional email template?”

Loops Workflow nodes API Add a node to a workflow “How do I insert a new step into a workflow?” Add a branch to a branch or experiment node “How do I add another path under a branch node?” Get a workflow node “How do I see the settings of a single workflow step?” Update a workflow node's settings “How do I change the configuration of one workflow step?”

Loops Contacts API Add a new contact “How do I add a new subscriber to my audience?” Update or upsert a contact “How do I change an existing contact's name or properties?” Find a contact by email or user ID “Is a given email address already a contact?” Delete a contact “How do I permanently remove someone from my audience?”

Loops Workflows API List workflows “What automated workflows do I have?” Create a draft workflow “How do I start a new email automation workflow?” Get a workflow's graph “How do I see all the steps and connections in a workflow?” Rename or redescribe a workflow “How do I rename an existing workflow?”

Loops Campaign groups API List campaign groups “Which groups are my campaigns organized into?” Create a campaign group “How do I make a new folder to organize campaigns?” Get a campaign group “How do I see the details of a single campaign group?” Rename or redescribe a campaign group “How do I rename an existing campaign group?”

Loops Themes API Get an email theme “How do I see the styles in a particular email theme?” Update an email theme “If I change a theme's styles, which emails are affected?” List email themes “Which email themes has my team created?” Create an email theme “How do I create a new theme to style my emails?”

Loops Campaigns API List campaigns “What email campaigns do I have in Loops?” Create a draft campaign “How do I start a new draft email campaign?” Get a campaign “How do I check the status and settings of one campaign?” Update a campaign's audience, group or schedule “How do I reschedule a draft campaign that already exists?”

Loops Components API Get an email component “How do I view the LMX body of a reusable email component?” Update an email component “If I edit a shared component, do the emails using it change too?” List email components “Which reusable email components exist on my team?” Create an email component “How do I create a reusable block I can drop into emails?”

Loops Email messages API Get an email message “How do I read the subject, sender and content of an email message?” Edit an email's subject, sender or content “How do I set the subject line and sender on a draft email?” Send a test preview of an email “How do I send myself a test copy of an email before it goes out?” Check an email for publishing errors “What errors are blocking this email from being published?”

Loops Transactional groups API List transactional groups “Which groups organize my transactional emails?” Create a transactional group “How do I create a folder for transactional emails?” Get a transactional group “How do I see one transactional group's details?” Rename or redescribe a transactional group “How do I rename an existing transactional group?”

Loops Audience segments API Get an audience segment “How do I look up the details of one audience segment?” List audience segments “What audience segments have we set up?” Create an audience segment “How do I create a saved audience segment from filter conditions?”

Loops Event patterns API List event patterns for workflow triggers “Which events can trigger a workflow?” Look up an event pattern by event name “What properties does the event named PaymentReceived carry?” Get an event pattern by ID “How do I fetch an event pattern when I only have its ID?”

Showing 12 of 18 APIs with phrasing — see every API.

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 76.6/100 · exemplar

Contract Quality 11.9 / 19

Developer Ergonomics 11.8 / 15

Access Clarity 15.0 / 15

Operational Transparency 7.2 / 10

Contract Governance 2.9 / 9

Discoverability 5.6 / 8

Regulatory Posture 5.9 / 15

Create-or-Update Ergonomics 1.1 / 10

Agent readiness — 65/100 · agent native

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 4 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

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.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too
Agentic Commerce Well-Known Document +5 pts — a parsing /.well-known/ucp.json or acp.json declaring a version and at least one service, OR (0.27) a live x402 payment challenge from _data/x402-adoption.json — `self` when its endpoints are on the provider's own domain, `platform` when they are on a vendor's
Well-Known Catalog +4 pts — common[].type includes WellKnown, APICatalog, or api-catalog
Consent & Bot Identity +3 pts — common[].type includes AIPREF, ContentSignal, WebBotAuth, or HTTPMessageSignatures

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 63.7 — up to +9.1 composite points
Contract Governance scores 31.8 — up to +8.2 composite points
Developer Ergonomics scores 78.6 — up to +4.3 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/loops/apis.yml: open an issue on github.com/api-evangelist/loops to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Agent Skills (SKILL.md packages)	covered	36.1	1	1
Stripe App Marketplace and Partner Ecosystem (builders on Stripe)	covered	36.1	1	1
Official SDKs on Packagist, pub.dev and Hex	covered	36.1	1	1
Bubble Plugin Marketplace (official vendor plugins on Bubble)	covered	36.1	1	1

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 6

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Model Context Protocol (MCP)

measured — observed by APIs.io (verified)

Agent Skills

measured — observed by APIs.io (published)

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

OpenAPI

measured — observed by APIs.io (published)

AsyncAPI

measured — observed by APIs.io (published)

OAuth 2.0

measured — observed by APIs.io (declared)

APIs 21

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

Loops API key API

Validate a Loops API key and discover which team it belongs to. 1 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Audience segments API

Read and create saved audience segments used to target campaigns and workflows. 3 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Campaign groups API

Organize campaigns into groups. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Campaigns API

Create, target, schedule and update email campaigns. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Components API

Create, read and update reusable LMX email components. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Configuration API

Read team configuration, including dedicated sending IP addresses. 1 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Contact properties API

Create and list the custom properties available on contacts. 2 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Contacts API

Create, update, find and delete contacts, and manage suppression status. 6 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Email messages API

Read, update, preview and Guardian-validate the LMX body of campaigns, workflow emails and transactional templates. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Event patterns API

Read the event patterns Loops has detected from incoming events, including their observed properties. 3 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Events API

Send events that update contact activity and trigger published workflows. 1 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Mailing lists API

List the mailing lists in your account. 1 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Themes API

Create, read and update reusable email themes. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Transactional emails API

Create, edit, publish, list and send transactional email templates with data variables. 8 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Transactional groups API

Organize transactional emails into groups. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Uploads API

Upload image assets for use in emails via a presigned-URL flow. 2 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Workflow nodes API

Create, read, update, delete and reroute the nodes of a workflow graph. 7 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops Workflows API

List, create, inspect and update automation workflows and their mailing-list targeting. 5 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).

Loops MCP Server

Remote Model Context Protocol server for Loops, reachable at https://mcp.loops.so over Streamable HTTP with OAuth 2.0 (PKCE, scope "mcp"). Exposes four meta-tools — search, desc...

Loops Webhooks

Outbound event surface. Seventeen signed event types covering contact lifecycle, mailing-list membership, and email delivery, engagement and complaint signals, delivered by HTTP...

Loops Webhooks API

Events Loops sends to your configured webhook endpoint when certain events happen in your account. Configure an endpoint in Settings → Webhooks. Each account supports one webhoo...

OPEN COLLECTION

Scroll for all 11

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Loops MCP Server

Remote MCP server at mcp.loops.so over streamable HTTP requiring OAuth; 4 tools listed.

Default API rate limit: 10 requests
Content API rate limit: 60 requests
Email sending rate — free plan: 10 emails

All 8 limits →

Billed by: subscribed contacts · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Loops Plans Pricing

3 plans

PLANS

Loops Price Estimates

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Loops Rate Limits

8 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Loops

SLA

FinOps 1

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

Loops Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Loops Webhooks

Event catalog for the Loops webhook surface, derived operation-for-operation from the `webhooks` block of the Loops OpenAPI 3.1 document (info.version 1.21.6, published at https...

ASYNCAPI

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Loops API Rules

56 rules · 45 errors 9 warnings 2 info

SPECTRAL

7 actions · update · loops-workflows-api-openapi.yml

DERIVED

Scroll for all 36

Security Posture 3

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

Loops Authentication

http/oauth2 · 2 schemes

SECURITY

Loops Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Loops Trust Center

SOC 2, EU-U.S. Data Privacy Framework, Swiss-U.S. Data Privacy Framework

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Loops Scopes

1 scope

1 scopes

SCOPES

Agentic Access 1

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

Loops Agentic Access

64 operations · 35 acting

AGENTIC

Resources

Get Started 5

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

Quickstart

SignUp

Login

Documentation 3

Reference material describing how the API behaves

AsyncAPI

AsyncAPI

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

MCPServer

AgentSkill

WellKnown

LLMsTxt

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Conventions

Idempotency

ErrorCatalog

DataModel

Webhooks

Lifecycle

Conformance

Scroll for all 7

Build 6

SDKs, sample code, and the tooling you integrate with

Examples

Packages

SDKs

CLI

ToolCrosswalk

GitHubOrganization

GitHubOrganization

Access & Security 5

Authentication, authorization, and security posture

Authentication

OAuthScopes

Compliance

TrustCenter

DomainSecurity

Operate 4

Status, limits, changes, and where to get help

RateLimits

StatusPage

ChangeLog

Support

Commercial 6

Pricing, plans, and the legal terms of use

Plans

FinOps

Pricing

TermsOfService

PrivacyPolicy

DataProcessingAgreement

DataProcessingAgreement

Company 3

The organization behind the API

Website

Website

Blog

Blog

LinkedIn

Other 2

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

Glossary

Glossary

Source (apis.yml)

aid: loops
url: https://raw.githubusercontent.com/api-evangelist/loops/refs/heads/main/apis.yml
name: Loops
kind: company
description: Loops is an email platform built for software companies, combining marketing campaigns, product and lifecycle
  automation, and transactional email on one contact model. Its REST API v1 exposes 64 operations across contacts, contact
  properties, mailing lists, audience segments, events and event patterns, campaigns, transactional emails, email messages
  authored in its own LMX markup, themes, components, uploads and workflow graphs, plus a 17-event signed webhook surface.
  Loops publishes its OpenAPI 3.1 document openly, ships first-party SDKs for JavaScript, Go, PHP, Ruby and Nuxt, a Go CLI,
  four versioned Agent Skills, and a hosted OAuth-protected MCP server at mcp.loops.so. Pricing is based on stored subscribed
  contacts rather than send volume, with a permanent free tier. The operating company is Astrodon Corporation.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: true
  label: Free plan, self-serve signup
  confidence: high
  source:
  - https://loops.so/pricing
  - https://loops.so/docs/api-reference/intro
  generated: '2026-08-13'
  method: searched
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/loops.png
tags:
- Email
- Email API
- Marketing Automation
- Transactional Email
- Lifecycle Email
- Webhook
- Software-as-a-Service
- Communications
- Developer Tools
- MCP
- Agents
- Campaigns
tags_raw:
- Email
- Email API
- Marketing Automation
- Transactional Email
- Lifecycle Email
- Webhooks
- SaaS
- Communications
- Developer Tools
- MCP
- Agents
- Campaigns
created: '2026-05-08'
modified: '2026-08-13'
specificationVersion: '0.23'
apis:
- aid: loops:loops-api-key-api
  name: Loops API key API
  description: Validate a Loops API key and discover which team it belongs to. 1 operation(s) in the Loops REST API v1 (OpenAPI
    1.21.6).
  humanURL: https://loops.so/docs/api-reference/api-key
  baseURL: https://app.loops.so/api/v1
  tags:
  - APIKeys
  tags_raw:
  - API key
  properties:
  - type: OpenAPI
    url: openapi/loops-api-key-api-openapi.yml
  - type: Overlay
    url: overlays/loops-api-key-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/api-key
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-audience-segments-api
  name: Loops Audience segments API
  description: Read and create saved audience segments used to target campaigns and workflows. 3 operation(s) in the Loops
    REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-audience-segments
  baseURL: https://app.loops.so/api/v1
  tags:
  - Audience Segments
  tags_raw:
  - Audience segments
  properties:
  - type: OpenAPI
    url: openapi/loops-audience-segments-api-openapi.yml
  - type: Overlay
    url: overlays/loops-audience-segments-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-audience-segments
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-campaign-groups-api
  name: Loops Campaign groups API
  description: Organize campaigns into groups. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-campaign-groups
  baseURL: https://app.loops.so/api/v1
  tags:
  - Campaign Groups
  tags_raw:
  - Campaign groups
  properties:
  - type: OpenAPI
    url: openapi/loops-campaign-groups-api-openapi.yml
  - type: Overlay
    url: overlays/loops-campaign-groups-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-campaign-groups
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-campaigns-api
  name: Loops Campaigns API
  description: Create, target, schedule and update email campaigns. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-campaigns
  baseURL: https://app.loops.so/api/v1
  tags:
  - Campaigns
  properties:
  - type: OpenAPI
    url: openapi/loops-campaigns-api-openapi.yml
  - type: Overlay
    url: overlays/loops-campaigns-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-campaigns
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-components-api
  name: Loops Components API
  description: Create, read and update reusable LMX email components. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-components
  baseURL: https://app.loops.so/api/v1
  tags:
  - Components
  properties:
  - type: OpenAPI
    url: openapi/loops-components-api-openapi.yml
  - type: Overlay
    url: overlays/loops-components-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-components
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-configuration-api
  name: Loops Configuration API
  description: Read team configuration, including dedicated sending IP addresses. 1 operation(s) in the Loops REST API v1
    (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/dedicated-sending-ips
  baseURL: https://app.loops.so/api/v1
  tags:
  - Configuration
  properties:
  - type: OpenAPI
    url: openapi/loops-configuration-api-openapi.yml
  - type: Overlay
    url: overlays/loops-configuration-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/dedicated-sending-ips
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-contact-properties-api
  name: Loops Contact properties API
  description: Create and list the custom properties available on contacts. 2 operation(s) in the Loops REST API v1 (OpenAPI
    1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-contact-properties
  baseURL: https://app.loops.so/api/v1
  tags:
  - Contact properties
  properties:
  - type: OpenAPI
    url: openapi/loops-contact-properties-api-openapi.yml
  - type: Overlay
    url: overlays/loops-contact-properties-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-contact-properties
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-contacts-api
  name: Loops Contacts API
  description: Create, update, find and delete contacts, and manage suppression status. 6 operation(s) in the Loops REST API
    v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/create-contact
  baseURL: https://app.loops.so/api/v1
  tags:
  - Contacts
  properties:
  - type: OpenAPI
    url: openapi/loops-contacts-api-openapi.yml
  - type: Overlay
    url: overlays/loops-contacts-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/create-contact
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-email-messages-api
  name: Loops Email messages API
  description: Read, update, preview and Guardian-validate the LMX body of campaigns, workflow emails and transactional templates.
    4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/get-email-message
  baseURL: https://app.loops.so/api/v1
  tags:
  - Email messages
  properties:
  - type: OpenAPI
    url: openapi/loops-email-messages-api-openapi.yml
  - type: Overlay
    url: overlays/loops-email-messages-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/get-email-message
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-event-patterns-api
  name: Loops Event patterns API
  description: Read the event patterns Loops has detected from incoming events, including their observed properties. 3 operation(s)
    in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-event-patterns
  baseURL: https://app.loops.so/api/v1
  tags:
  - Event patterns
  properties:
  - type: OpenAPI
    url: openapi/loops-event-patterns-api-openapi.yml
  - type: Overlay
    url: overlays/loops-event-patterns-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-event-patterns
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-events-api
  name: Loops Events API
  description: Send events that update contact activity and trigger published workflows. 1 operation(s) in the Loops REST
    API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/send-event
  baseURL: https://app.loops.so/api/v1
  tags:
  - Event
  tags_raw:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/loops-events-api-openapi.yml
  - type: Overlay
    url: overlays/loops-events-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/send-event
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-mailing-lists-api
  name: Loops Mailing lists API
  description: List the mailing lists in your account. 1 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-mailing-lists
  baseURL: https://app.loops.so/api/v1
  tags:
  - Mailing Lists
  tags_raw:
  - Mailing lists
  properties:
  - type: OpenAPI
    url: openapi/loops-mailing-lists-api-openapi.yml
  - type: Overlay
    url: overlays/loops-mailing-lists-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-mailing-lists
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-themes-api
  name: Loops Themes API
  description: Create, read and update reusable email themes. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-themes
  baseURL: https://app.loops.so/api/v1
  tags:
  - Themes
  properties:
  - type: OpenAPI
    url: openapi/loops-themes-api-openapi.yml
  - type: Overlay
    url: overlays/loops-themes-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-themes
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-transactional-emails-api
  name: Loops Transactional emails API
  description: Create, edit, publish, list and send transactional email templates with data variables. 8 operation(s) in the
    Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/send-transactional-email
  baseURL: https://app.loops.so/api/v1
  tags:
  - Transactional Emails
  tags_raw:
  - Transactional emails
  properties:
  - type: OpenAPI
    url: openapi/loops-transactional-emails-api-openapi.yml
  - type: Overlay
    url: overlays/loops-transactional-emails-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/send-transactional-email
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-transactional-groups-api
  name: Loops Transactional groups API
  description: Organize transactional emails into groups. 4 operation(s) in the Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-transactional-groups
  baseURL: https://app.loops.so/api/v1
  tags:
  - Transactional groups
  properties:
  - type: OpenAPI
    url: openapi/loops-transactional-groups-api-openapi.yml
  - type: Overlay
    url: overlays/loops-transactional-groups-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-transactional-groups
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-uploads-api
  name: Loops Uploads API
  description: Upload image assets for use in emails via a presigned-URL flow. 2 operation(s) in the Loops REST API v1 (OpenAPI
    1.21.6).
  humanURL: https://loops.so/docs/api-reference/create-upload
  baseURL: https://app.loops.so/api/v1
  tags:
  - Uploads
  properties:
  - type: OpenAPI
    url: openapi/loops-uploads-api-openapi.yml
  - type: Overlay
    url: overlays/loops-uploads-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/create-upload
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-workflow-nodes-api
  name: Loops Workflow nodes API
  description: Create, read, update, delete and reroute the nodes of a workflow graph. 7 operation(s) in the Loops REST API
    v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/get-workflow-node
  baseURL: https://app.loops.so/api/v1
  tags:
  - Workflow nodes
  properties:
  - type: OpenAPI
    url: openapi/loops-workflow-nodes-api-openapi.yml
  - type: Overlay
    url: overlays/loops-workflow-nodes-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/get-workflow-node
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-workflows-api
  name: Loops Workflows API
  description: List, create, inspect and update automation workflows and their mailing-list targeting. 5 operation(s) in the
    Loops REST API v1 (OpenAPI 1.21.6).
  humanURL: https://loops.so/docs/api-reference/list-workflows
  baseURL: https://app.loops.so/api/v1
  tags:
  - Workflows
  properties:
  - type: OpenAPI
    url: openapi/loops-workflows-api-openapi.yml
  - type: Overlay
    url: overlays/loops-workflows-overlay.yaml
  - type: Documentation
    url: https://loops.so/docs/api-reference/list-workflows
  - type: APIReference
    url: https://loops.so/docs/api-reference/intro
- aid: loops:loops-mcp-server
  name: Loops MCP Server
  description: Remote Model Context Protocol server for Loops, reachable at https://mcp.loops.so over Streamable HTTP with
    OAuth 2.0 (PKCE, scope "mcp"). Exposes four meta-tools — search, describe, execute and teams — that let an agent discover
    and run any operation in the Loops REST API for any team the signed-in user can access.
  humanURL: https://loops.so/docs/mcp-server
  baseURL: https://mcp.loops.so
  tags:
  - MCP
  - Agents
  - Email
  properties:
  - type: MCPServer
    url: mcp/loops-mcp.yml
  - type: ToolCrosswalk
    url: mcp/loops-tool-crosswalk.yml
  - type: OAuthScopes
    url: scopes/loops-scopes.yml
  - type: Documentation
    url: https://loops.so/docs/mcp-server
- aid: loops:loops-webhooks
  name: Loops Webhooks
  description: Outbound event surface. Seventeen signed event types covering contact lifecycle, mailing-list membership, and
    email delivery, engagement and complaint signals, delivered by HTTP POST to one subscriber-configured endpoint per account
    and verified with an HMAC-SHA256 signature over {webhook-id}.{webhook-timestamp}.{raw-body}.
  humanURL: https://loops.so/docs/webhooks
  baseURL: https://app.loops.so/api/v1
  tags:
  - Webhook
  - Event
  - Email
  tags_raw:
  - Webhooks
  - Events
  - Email
  properties:
  - type: AsyncAPI
    url: asyncapi/loops-webhooks-asyncapi.yml
  - type: Webhooks
    url: asyncapi/loops-webhooks-asyncapi.yml
  - type: Documentation
    url: https://loops.so/docs/webhooks
- aid: loops:loops-webhooks-api
  name: Loops Webhooks API
  description: Events Loops sends to your configured webhook endpoint when certain events happen in your account. Configure
    an endpoint in Settings → Webhooks. Each account supports one webhook endpoint. Events are signed with `webhook-id`, `webhook-timestamp`,
    and `webhook-signature` headers and delivered at a maximum rate of 10 per second. See https://loops.so/docs/webhooks for
    setup, verification, and payload details.
  humanURL: https://loops.so/docs/api-reference/api-key
  baseURL: https://app.loops.so/api/v1
  tags:
  - Webhook
  tags_raw:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/loops-webhooks-api-openapi.yml
common:
- type: CapabilityMap
  url: capabilities/loops-capability-edges.yml
  name: Loops Business Capability Map
- type: AgenticAccess
  url: agentic-access/loops-agentic-access.yml
- type: Authentication
  url: authentication/loops-authentication.yml
- type: OAuthScopes
  url: scopes/loops-scopes.yml
- type: Conventions
  url: conventions/loops-conventions.yml
- type: Idempotency
  url: conventions/loops-conventions.yml
- type: ErrorCatalog
  url: errors/loops-problem-types.yml
- type: RateLimits
  url: rate-limits/loops-rate-limits.yml
- type: Plans
  url: plans/loops-plans-pricing.yml
- type: FinOps
  url: finops/loops-finops.yml
- type: DataModel
  url: data-model/loops-data-model.yml
- type: Examples
  url: examples/loops-examples.yml
- type: Packages
  url: packages/loops-packages.yml
- type: SDKs
  url: packages/loops-packages.yml
- type: CLI
  url: cli/loops-cli.yml
- type: MCPServer
  url: mcp/loops-mcp.yml
- type: ToolCrosswalk
  url: mcp/loops-tool-crosswalk.yml
- type: AgentSkill
  url: skills/_index.yml
- type: AsyncAPI
  url: asyncapi/loops-webhooks-asyncapi.yml
- type: Webhooks
  url: asyncapi/loops-webhooks-asyncapi.yml
- type: WellKnown
  url: well-known/loops-well-known.yml
- type: Lifecycle
  url: lifecycle/loops-lifecycle.yml
- type: StatusPage
  url: https://status.loops.so
- type: ChangeLog
  url: changelog/loops-changelog.yml
- type: Conformance
  url: conformance/loops-conformance.yml
- type: Compliance
  url: conformance/loops-conformance.yml
- type: TrustCenter
  url: security/loops-trust-center.yml
- type: DomainSecurity
  url: security/loops-domain-security.yml
- type: LLMsTxt
  url: llms/loops-llms.txt
- type: Website
  url: https://loops.so/
- type: DeveloperPortal
  url: https://loops.so/docs
- type: Documentation
  url: https://loops.so/docs
- type: APIReference
  url: https://loops.so/docs/api-reference/intro
- type: GettingStarted
  url: https://loops.so/docs/quickstart
- type: Quickstart
  url: https://loops.so/docs/quickstart-agents
- type: Support
  url: https://app.loops.so/settings?page=support
- type: Blog
  url: https://loops.so/engineering
- type: GitHubOrganization
  url: https://github.com/Loops-so
- type: Pricing
  url: https://loops.so/pricing
- type: SignUp
  url: https://app.loops.so/register
- type: Login
  url: https://app.loops.so/
- type: TermsOfService
  url: https://loops.so/terms
- type: PrivacyPolicy
  url: https://loops.so/privacy
- type: DataProcessingAgreement
  url: https://loops.so/dpa
- type: LinkedIn
  url: https://www.linkedin.com/company/sendwithloops
- type: Integrations
  url: https://loops.so/docs/integrations
- type: Glossary
  url: https://loops.so/glossary
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 49
  pass: local-v1

Loops API — frequently asked questions

Does Loops have an API?

Yes. APIs.io lists 21 APIs from Loops, including Loops API key API, Loops Audience segments API and Loops Campaign groups API, and 18 more.

Is there an OpenAPI specification for the Loops API?

Yes. APIs.io indexes 19 OpenAPI specifications for Loops, each linked for download from this page.

How do I authenticate with the Loops API?

Loops documents its authentication (http/oauth2 · 2 schemes). The details are profiled on APIs.io as Loops Authentication.

How much does the Loops API cost?

Loops publishes its prices; its Free plan is $0 as of 2026-10-28. APIs.io lists 3 pricing plans for Loops, with each plan's price, limits and inclusions under Pricing on this page.

Does Loops have an MCP server?

Yes. APIs.io lists 1 MCP server for Loops: Remote MCP server at mcp.loops.so over streamable HTTP requiring OAuth; 4 tools listed.

Is the Loops API ready for AI agents?

Loops has a Kin Score of 76.6 out of 100 (exemplar) and an Agent Readiness score of 65.0 (agent-native), scored by API Evangelist on 2026-11-06.

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