Peer39

Peer39 External API

The Peer39 External API manages Custom Categories — contextual targeting and brand-safety lists of keywords, URLs, mobile apps or CTV apps — and syncs them to a connected DSP partner. Nine operations are known: session login, list/get/create/ full-update/metadata-update/items-update/delete of custom categories, and a URL-example prediction preview. Authentication is a session bearer token obtained by POSTing a username and password to /api/external/login; the account must carry the "External API" and "RTB Buyer" roles, which are granted by a Peer39 integration manager. The API is credential-gated and publicly undocumented — Peer39 publishes no API reference page and no OpenAPI. This profile is derived from Peer39's own publicly readable MCP server source plus live probes of the API host, and every path under /api/external returns HTTP 401 unauthenticated.

GitHub

Documentation

📖
Authentication
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/authentication/peer39-authentication.yml
📖
RateLimits
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/rate-limits/peer39-rate-limits.yml

Other Resources

🔗
Conventions
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/conventions/peer39-conventions.yml
🔗
ErrorCatalog
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/errors/peer39-problem-types.yml
🔗
DataModel
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/data-model/peer39-data-model.yml
🔗
Lifecycle
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/lifecycle/peer39-lifecycle.yml
🔗
MCPServer
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/mcp/peer39-mcp.yml
🔗
ToolCrosswalk
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/mcp/peer39-tool-crosswalk.yml
🔗
Login
https://app.peer39.com/login
🔗
APIsJSON
https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/apis.yml

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API 
curl "https://apis.io/api/v1/apis/peer39-external-api"
All apis 
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

API entry from apis.yml

apis.yml Raw ↑ 
aid: peer39-external-api
name: Peer39 External API
description: 'The Peer39 External API manages Custom Categories — contextual targeting and brand-safety
  lists of keywords, URLs, mobile apps or CTV apps — and syncs them to a connected DSP partner. Nine operations
  are known: session login, list/get/create/ full-update/metadata-update/items-update/delete of custom
  categories, and a URL-example prediction preview. Authentication is a session bearer token obtained
  by POSTing a username and password to /api/external/login; the account must carry the "External API"
  and "RTB Buyer" roles, which are granted by a Peer39 integration manager. The API is credential-gated
  and publicly undocumented — Peer39 publishes no API reference page and no OpenAPI. This profile is derived
  from Peer39''s own publicly readable MCP server source plus live probes of the API host, and every path
  under /api/external returns HTTP 401 unauthenticated.'
humanURL: https://app.peer39.com
baseURL: https://app.peer39.com
tags:
- Contextual Targeting
- Brand Safety
- Custom Categories
- AdTech
- DSP
properties:
- type: Authentication
  url: authentication/peer39-authentication.yml
- type: Conventions
  url: conventions/peer39-conventions.yml
- type: ErrorCatalog
  url: errors/peer39-problem-types.yml
- type: DataModel
  url: data-model/peer39-data-model.yml
- type: Lifecycle
  url: lifecycle/peer39-lifecycle.yml
- type: RateLimits
  url: rate-limits/peer39-rate-limits.yml
- type: MCPServer
  url: mcp/peer39-mcp.yml
- type: ToolCrosswalk
  url: mcp/peer39-tool-crosswalk.yml
- type: Login
  url: https://app.peer39.com/login