# Omnicom Group Inc.

> Omnicom Group Inc. (NYSE: OMC) is the world's largest marketing and sales
> communications holding company, formed in its current shape when Omnicom
> completed its acquisition of Interpublic Group on 26 November 2025 (pro forma
> combined revenue in excess of $25 billion). It operates across advertising,
> media, precision marketing, commerce, public relations, healthcare, branding,
> experiential and production in more than 100 countries, through networks
> including BBDO, DDB, TBWA, OMD, PHD, Hearts & Science, McCann, FCB,
> Mediabrands, Flywheel and Acxiom. Its Omni platform — built and run by
> Annalect, Omnicom's data, technology and AI division — is marketed as an
> AI-driven marketing intelligence operating system.

generated: 2026-08-12
method: generated
source: apis.yml + artifacts in this repository (no /llms.txt is published by the
provider; https://www.omc.com/llms.txt returns 404 and
https://omni.omc.com/llms.txt returns the platform's Angular shell)

## API surface

Omnicom publishes **no public API**. As of the 2026-08-12 probe there is no
developer portal, no API reference, no OpenAPI/Swagger/AsyncAPI/GraphQL
document, no first-party SDK on npm, PyPI or any other public registry, no
public MCP server, and no A2A agent card on any Omnicom host.

Contract discovery was run against every host the company controls:

- `www.omc.com` — WordPress corporate site. `/openapi.json`, `/swagger.json`,
  `/api-docs`, `/llms.txt`, `/security.txt` and every `/.well-known/*` path
  return HTTP 404. `/wp-json/` returns HTTP 403 (WAF), so even the CMS API is
  closed.
- `omni.omc.com` — the Omni platform. An Angular single-page application behind
  Imperva that 301-redirects every unknown path to `/home/` and then serves the
  same HTML shell with HTTP 200. Every 200 on this host is a catch-all, not a
  document; `/openapi.json`, `/graphql`, `/.well-known/agent-card.json` and
  `/.well-known/agent.json` all return that shell.
- `api.omc.com`, `developer.omc.com`, `docs.omc.com`, `platform.omc.com` — do
  not resolve in DNS.
- `www.omnicomgroup.com` — the legacy corporate domain; 301-redirects to
  `www.omc.com`.

The Omni product page describes the platform as "interoperable by design" and
Omnicom has publicly announced integrations it *consumes* (Instacart Developer
Platform, The Trade Desk, InfoSum, Affinity Solutions), but the platform's own
programmatic surface is delivered to agencies and clients rather than published.

## Company

- [Omnicom](https://www.omc.com/): Company home.
- [About](https://www.omc.com/about/): Company background.
- [Corporate leadership](https://www.omc.com/about/corporate-leadership/)
- [Capability leadership](https://www.omc.com/about/capability-leadership/)
- [Corporate governance](https://www.omc.com/about/corporate-governance/)
- [Investor relations](https://investor.omc.com): SEC filings and results.
- [Newsroom](https://www.omc.com/news/)
- [LinkedIn](https://www.linkedin.com/company/omnicom)

## Platform

- [Omni](https://www.omc.com/omni/): AI-driven marketing intelligence platform —
  central orchestration, personalized production at scale, predictive
  intelligence, an identity backbone on Acxiom Real ID, outcome-driven
  activation and localized optimization.
- [Omni platform host](https://omni.omc.com/home/): Client/agency application
  (Angular SPA, no public API surface).
- [Annalect](https://www.annalect.com/): Omnicom's data, technology, analytics
  and AI division; builds and operates Omni.

## Capabilities

- [All capabilities](https://www.omc.com/capabilities/)
- [Advertising](https://www.omc.com/capabilities/capability-advertising/)
- [Media](https://www.omc.com/capabilities/capability-media/)
- [Precision marketing](https://www.omc.com/capabilities/capability-precision-marketing/)
- [Commerce](https://www.omc.com/capabilities/capability-commerce/)
- [Public relations](https://www.omc.com/capabilities/capability-public-relations/)
- [Health](https://www.omc.com/capabilities/capability-health/)
- [Branding](https://www.omc.com/capabilities/capability-branding/)
- [Experiential](https://www.omc.com/capabilities/capability-experiential/)
- [Production](https://www.omc.com/capabilities/capability-production/)

## Legal

- [Terms of use](https://www.omc.com/terms-of-use/)
- [Privacy notice](https://www.omc.com/privacy-notice/)
- [Cookie consent](https://www.omc.com/cookie-consent/)

## Culture

- [Culture](https://www.omc.com/culture/)
- [Careers](https://www.omc.com/culture/careers/)
- [Learning and development](https://www.omc.com/culture/learning-and-development/)
- [Inclusion and impact](https://www.omc.com/culture/inclusion-and-impact/)

## Code

- [github.com/annalect](https://github.com/annalect): Annalect's public GitHub
  organization — nine repositories of internal engineering tooling (Airflow
  Docker images, ChatScript, Conda provisioning, Flask session, ES module
  helpers). No API specifications and no client libraries; most repositories
  were last pushed between 2018 and 2023.

## API Evangelist artifacts

- [security/omnicom-domain-security.yml](security/omnicom-domain-security.yml):
  TLS/HSTS/DNSSEC/CAA/SPF/DMARC probe of omc.com.
- [well-known/omnicom-well-known.yml](well-known/omnicom-well-known.yml):
  /.well-known/ probe record across all three hosts (all 404 or catch-all).
- [security/omnicom-vulnerability-disclosure.yml](security/omnicom-vulnerability-disclosure.yml):
  negative record — no disclosure program is published; the HackerOne page at
  hackerone.com/omnicom is an unclaimed community-curated directory entry with a
  null policy, not an Omnicom-run program, and must not be credited as one.