# Interpublic Group (IPG)

> An advertising and marketing-services holding company (McCann Worldgroup, IPG Mediabrands, FCB, MullenLowe Group, Acxiom), acquired by Omnicom. IPG publishes no developer portal, no product API and no OpenAPI. The one live machine-readable contract on its own hosts is the WordPress REST API still served from the apex host interpublic.com, which carries a frozen 346-post corporate newsroom archive and advertises 254 routes across 17 namespaces in a self-describing discovery document. This file was generated by API Evangelist from that document and from live probes on 2026-08-12; Interpublic Group does not serve an llms.txt (HTTP 404).

## Read this first

- Use the APEX host `https://interpublic.com`. `https://www.interpublic.com` 301-redirects every path to `https://www.omc.com/` after the Omnicom acquisition, and returns the Omnicom homepage as HTML with HTTP 200 — never treat that as a document.
- Reads are anonymous. Writes and privileged reads need a WordPress cookie plus `X-WP-Nonce`, which no third party can obtain.
- Errors are `{code, message, data:{status}}` as `application/json`. Not RFC 9457.
- The archive is frozen: newest post 2025-11-24.

## APIs

- [WordPress REST index](https://interpublic.com/wp-json/): the authoritative self-describing contract — 254 routes, 17 namespaces, site identity `name: "IPG"`.
- [wp/v2 content API](https://interpublic.com/wp-json/wp/v2/posts): posts, pages, media, taxonomies, search, types. Anonymous HTTP 200.
- [wp-abilities/v1](https://interpublic.com/wp-json/wp-abilities/v1/abilities): the WordPress Abilities registry — the agent-facing surface on this install. Capability-gated, HTTP 401 `rest_forbidden` anonymously (a control path returns 404, so the surface genuinely exists).
- [oembed/1.0](https://interpublic.com/wp-json/oembed/1.0/embed): oEmbed discovery and proxy. Anonymous HTTP 200.

## Specs

- openapi/interpublic-wp-v2-api-openapi.yml — 114 paths, 250 operations
- openapi/interpublic-wp-abilities-v1-api-openapi.yml — 6 paths
- openapi/interpublic-oembed-1-0-api-openapi.yml — 3 paths
- openapi/interpublic-root-api-openapi.yml — 2 paths
- openapi/interpublic-wp-rest-discovery-original.json — the verbatim fetched source document

## Operating knowledge

- conventions/interpublic-conventions.yml — pagination (`page`/`per_page`, `X-WP-Total`, `X-WP-TotalPages`, `Link rel="next"` rewritten to the www host), field selection (`_fields`, `_embed`, `context`), no idempotency, no request-id.
- authentication/interpublic-authentication.yml — anonymous reads, cookie + `X-WP-Nonce` for everything else, no OAuth anywhere.
- errors/interpublic-problem-types.yml — `rest_forbidden`, `rest_user_cannot_view`, `rest_no_route`, each observed live.
- data-model/interpublic-data-model.yml — post → author/featured_media/categories/tags, plus three custom post types (`ci_lead_form`, `supplier_lead_form`, `icons`).
- lifecycle/interpublic-lifecycle.yml — acquisition state, frozen content, and the unrouted Apigee gateway on api.interpublic.com.
- rate-limits/interpublic-rate-limits.yml — no published limits, no rate-limit headers returned.
- plans/interpublic-plans-pricing.yml — no developer pricing of any kind.

## Skills

- skills/interpublic-read-newsroom.md — read and page the newsroom archive.
- skills/interpublic-discover-surface.md — discover what is actually callable, and the dead ends.

## Dead ends (probed 2026-08-12, do not retry blindly)

- https://api.interpublic.com/* — live Apigee gateway, no proxy bound; every path including a nonsense control returns `messaging.adaptors.http.flow.ApplicationNotFound`.
- https://investors.interpublic.com/* — HTTP 403 to everything including a control; bot-blocked.
- https://interpublic.com/.well-known/security.txt — HTTP 404. No security.txt, no OAuth metadata, no agent card, no api-catalog on any host.
- https://interpublic.com/llms.txt — HTTP 404.