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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 20 APIs on the APIs.io network, including API key API, Audience segments API, Campaign groups API, and 17 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.
Loops’ developer surface includes authentication, code examples, CLI, changelog, documentation, API reference, getting-started guide, and 39 more developer resources.
1 APIs1 MCP Servers
On this page
Kin Score
APIs 21
Open Collections 12
MCP Servers 1
Pricing Plans 1
Rate Limits 1
FinOps 1
Event Specs 1
Security Posture 3
Scopes 1
Agentic Access 1
Resources 46
apis.yml
74 Operational Transparency
11 Create-or-Update Ergonomics
Composite quality — 69.1/100 · exemplar
Agent readiness — 58/100 · agent native
Individual APIs this provider publishes, each with its own machine-readable definition.
Scroll for all 21
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Scroll for all 12
Model Context Protocol servers that expose these APIs to AI agents.
Published pricing tiers and plan structures.
Documented rate limits and quota policies.
Cost, billing, and metering signals for API financial operations.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
OAuth scopes governing access to this provider's APIs.
Recommended x-agentic-access execution contracts for AI agents.
Get Started 5
Portal, sign-up, and the first successful call
Documentation 3
Reference material describing how the API behaves
Agent Surfaces 5
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 7
Pagination, idempotency, versioning, errors, and events
Scroll for all 7
Build 6
SDKs, sample code, and the tooling you integrate with
Access & Security 5
Authentication, authorization, and security posture
Operate 4
Status, limits, changes, and where to get help
Commercial 6
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 2
Properties that don't map to a standard resource type
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
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
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