# Sailthru

**Canonical:** https://apis.io/providers/sailthru/  
**Website:** https://zetaglobal.com/sailthru/  
**APIs profiled:** 2

Sailthru is a cross-channel relationship-marketing and personalization platform built for media, publishing, retail and e-commerce brands, unifying email, SMS, mobile push, in-app and on-site messaging around a single customer profile with predictive segmentation and 1:1 content personalization. Founded in New York in 2008, it was acquired by CM Group (later Marigold) in 2018 and became part of Zeta Global in November 2025 when Zeta bought Marigold's enterprise software business; the product is now documented as Sailthru by Zeta. Its public HTTPS API lives at api.sailthru.com and covers users, lists, content, templates, blasts (campaigns), transactional sends, triggers, purchases, events, includes, ad plans and stats, authenticated with an api_key plus an MD5 signature computed over the request parameters. It is complemented by the Zephyr template language, a JavaScript on-site personalization tag, mobile SDKs, and API postbacks (webhooks) for opt-out, hardbounce, verify and profile-update events.

## Kin Score — 53.6 / 100 (developing)

Scored 2026-08-17 under rubric 0.11.0. Trend: flat (+0.0 from 53.6).

| Facet | Score |
|---|---|
| Discoverability | 75.9 |
| Contract Quality | 51.6 |
| Governance | 12.5 |
| Operational Transparency | 71.1 |
| Developer Ergonomics | 65.2 |
| Commercial Clarity | 50.0 |

Regulatory layer — **Telecommunications**: 50.0 (matched via tags).

## Agent readiness — 37.4 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | no |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | documented |
| OpenAPI Examples | no |
| 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 |

## APIs (2)

- **Sailthru API** — The core Sailthru HTTPS API. All requests are GET, POST or DELETE calls to https://api.sailthru.com/<endpointName>, authenticated with api_key, an MD5 sig over the sorted parame...
- **Sailthru JavaScript API (Personalization Engine)** — The client-side Sailthru JavaScript tag (spm.v1.min.js, served from ak.sail-horizon.com) used for on-site behavior tracking, content-library sync, userSignUp/userSignUpConfirm c...

## Security (4)

- **Sailthru Authentication** — apiKey/requestSignature · 3 schemes
- **Sailthru Domain Security** — TLSv1.3 · HSTS · DMARC
- **Sailthru Vulnerability Disclosure** — Bugcrowd · security.txt
- **Sailthru Trust Center** — SOC 2 Type 2, ISO/IEC 27001, ISO/IEC 27018:2019, ISO/IEC 27701, HDS, Privacy Mark, SOX, GDPR, CCPA, HITRUST, SIG Core, CAIQ, SOC 1 Type 2

## Plans (1)

- **Sailthru Plans Pricing**

## Tags

Company, Email Marketing, Marketing Automation, Personalization, Customer Data Platform, Transactional Email, SMS, Push Notifications, Retail, Media and Publishing

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