# Epsilon

**Canonical:** https://apis.io/providers/epsilon/  
**Website:** https://epsilon.com/  
**APIs profiled:** 4

Epsilon is a Publicis Groupe marketing and advertising technology company that operates identity-led, data-driven marketing across paid, owned and earned channels. Its public, machine-readable API surface sits almost entirely inside Epsilon Retail Media (the platform built on CitrusAd, which Publicis acquired in 2021 and folded into Epsilon), whose developer hub at developers.citrusad.com publishes an Integration API for syncing catalogs, products, customers and orders and for generating product, banner and Banner X ads; a Filter Mapping API; a Cross-Sell Category API; and a Brand Pages API served from regional *.rmn.dotomi.com hosts. Epsilon also runs Epsilon PeopleCloud (loyalty, CRM, digital media) and CORE Private Exchange for publishers, but neither publishes a public machine-readable contract. API access is provisioned by a Technical Account Manager rather than self-service signup.

## Kin Score — 40.5 / 100 (thin)

Scored 2026-08-17 under rubric 0.11.0. Trend: flat (+0.0 from 40.5).

| Facet | Score |
|---|---|
| Discoverability | 81.5 |
| Contract Quality | 50.5 |
| Governance | 20.8 |
| Operational Transparency | 0.0 |
| Developer Ergonomics | 65.2 |
| Commercial Clarity | 21.1 |

## Agent readiness — 43.2 (agent-ready)

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

## APIs (4)

- **Epsilon Retail Media Integration API** — The core Epsilon Retail Media (CitrusAd) REST API. Retailers use it to sync product catalogs, catalog products, customers and order data into the platform, and to request produc...
- **Epsilon Retail Media Brand Pages API** — Serves brand-page content modules for retailer-hosted brand landing pages. A retailer routes /brands/{slug} on its own domain, calls POST /ads/v3/brand-pages on its assigned reg...
- **Epsilon Retail Media Filter Mapping API** — Manages filter mappings that translate a retailer's own product filter vocabulary into the filters Epsilon Retail Media applies when selecting ads. Five operations — create, lis...
- **Epsilon Retail Media Cross-Sell Category API** — Manages cross-sell category definitions used by the category cross-sell ad placement, where ads for one category are shown against products in a different, related category. Fou...

## Security (2)

- **Epsilon Authentication** — apiKey/http-basic/oauth2/jwt-bearer · 4 schemes
- **Epsilon Domain Security** — TLSv1.2 · HSTS · DMARC

## Plans (1)

- **Epsilon Plans Pricing**

## Tags

Company, Marketing, Advertising, Retail Media, Advertising Technology, Identity Resolution, Customer Data, Loyalty, Retail, Publicis Groupe

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