# Loops

**Canonical:** https://apis.io/providers/loops/  
**Website:** https://loops.so/  
**APIs profiled:** 20

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.

## Kin Score — 72.0 / 100 (exemplar)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 72.0).

| Facet | Score |
|---|---|
| Discoverability | 92.6 |
| Contract Quality | 63.8 |
| Governance | 30.3 |
| Contract Governance | 30.3 |
| Operational Transparency | 73.7 |
| Developer Ergonomics | 78.6 |
| Commercial Clarity | 89.5 |
| Access Clarity | 89.5 |

## Agent readiness — 60.1 (agent-native)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | documented |
| Auth Clarity | yes |
| Idempotency | verified |
| Error Semantics | verified |
| OpenAPI Examples | partial |
| Rate Limit Signal | documented |
| Event Surface Described | yes |
| Agent Skills | yes |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Free plan, self-serve signup — onboarding: self-serve, pricing: freemium, trial: no (confidence: high).

## APIs (20)

- **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...

## MCP servers (1)

- **Loops MCP Server**

## Agentic access (1)

- **Loops Agentic Access** — 24 operations · 10 acting

## Security (3)

- **Loops Authentication** — http/oauth2 · 2 schemes
- **Loops Domain Security** — TLSv1.3 · HSTS · DMARC
- **Loops Trust Center** — SOC 2, EU-U.S. Data Privacy Framework, Swiss-U.S. Data Privacy Framework

## Plans (1)

- **Loops Plans Pricing**

## Tags

Email, Email API, Marketing Automation, Transactional Email, Lifecycle Email, Webhook, Software-as-a-Service, Communications, Developer Tools, MCP, Agents, Campaigns

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/loops/). Scores are computed from the provider's own public artifacts under a published rubric.