# Loops

**Canonical:** https://apis.io/providers/loops-so/  
**Website:** https://loops.so  
**APIs profiled:** 12

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.

## Kin Score — 46.8 / 100 (developing)

Scored 2026-08-25 under rubric 0.14.0. Trend: flat (+0.0 from 46.8).

| Facet | Score |
|---|---|
| Discoverability | 64.8 |
| Contract Quality | 55.4 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 39.5 |
| Developer Ergonomics | 61.9 |
| Commercial Clarity | 44.7 |
| Access Clarity | 44.7 |

## Agent readiness — 38.8 (agent-native)

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

## Access

Self-serve signup — onboarding: self-serve, pricing: unknown, trial: no (confidence: medium).

## APIs (12)

- **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

## Agentic access (1)

- **Loops So Agentic Access** — 26 operations · 12 acting

## Security (2)

- **Loops So Authentication** — http · 1 scheme
- **Loops So Domain Security** — TLSv1.3 · HSTS · DMARC

## Tags

Email, Marketing Email, Transactional Email, Email Automation, Email Campaigns, Email Workflows, Contacts, Audience Management, Event, Webhook, Software-as-a-Service, Developer Tools

---

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