Peer39

Peer39 is a contextual advertising and intelligence company that provides pre-bid controls and post-buy analytics built on verified contextual data for programmatic media buyers. Its platform delivers contextual targeting, brand safety and suitability, and contextual analytics across web, mobile, and connected TV (CTV) and video environments, helping advertisers and platforms make privacy-forward, cookieless media decisions. Peer39 was surfaced as a portfolio company of Canaan Partners and added to the API Evangelist network. Peer39 does operate a real REST API — the Peer39 External API at https://app.peer39.com/api/external — for creating, updating and deleting Custom Categories (contextual targeting and brand-safety lists of keywords, URLs, mobile apps and CTV apps) and syncing them to connected DSPs such as The Trade Desk, Microsoft Advertising/Xandr, Basis, Yahoo and Amazon. That API is entirely undocumented in public: there is no developer portal, no API reference page, no OpenAPI specification and no published SDK. Credentials are provisioned by a Peer39 account or integration manager who grants the "External API" and "RTB Buyer" roles on a named account, and API documentation is distributed as PDFs rather than published on the web. A first-party-authored MCP server for the API exists in pre-release on a personal GitHub account and is the only public description of the surface.

Peer39 publishes 1 API on the APIs.io network. Tagged areas include Company, Contextual Advertising, AdTech, Brand Safety, and Programmatic Advertising.

Peer39’s developer surface includes engineering blog, getting-started guide, signup flow, support, and 9 more developer resources.

20.5/100 emerging ▬ flat Agent 7/100 agent aware Full breakdown ↓
scored 2026-08-17 · rubric v0.11.0
AccessEnterprise
1 APIs 1 MCP Servers
CompanyContextual AdvertisingAdTechBrand SafetyProgrammatic AdvertisingContextual TargetingCTVMarTechAdvertisingCustom CategoriesDSP

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-17 · rubric v0.11.0
Composite quality — 20.5/100 · emerging
Contract Quality 0.0 / 25
Developer Ergonomics 3.5 / 20
Commercial Clarity 6.8 / 20
Operational Transparency 0.0 / 13
Governance 1.5 / 12
Discoverability 8.7 / 10
Agent readiness — 7/100 · agent aware
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/peer39: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

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 pa...

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

peer39-mcp.yml

MCP SERVER

Pricing Plans 1

Published pricing tiers and plan structures.

Peer39 Plans Pricing

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Peer39 Rate Limits

0 limits

RATE LIMITS

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Peer39 Authentication

2 schemes

SECURITY

Peer39 Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Build 1

SDKs, sample code, and the tooling you integrate with

Access & Security 1

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

Source (apis.yml)

apis.yml Raw ↑
aid: peer39
accessModel:
  pricing: enterprise
  onboarding: sales
  trial: false
  try_now: false
  public: false
  label: Enterprise / Contact Sales
  confidence: high
  source:
  - https://www.peer39.com/platform-demo
  - https://www.peer39.com/contact-us
  generated: '2026-08-12'
  method: searched
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/peer39.png
name: Peer39
description: 'Peer39 is a contextual advertising and intelligence company that provides pre-bid controls and post-buy analytics
  built on verified contextual data for programmatic media buyers. Its platform delivers contextual targeting, brand safety
  and suitability, and contextual analytics across web, mobile, and connected TV (CTV) and video environments, helping advertisers
  and platforms make privacy-forward, cookieless media decisions. Peer39 was surfaced as a portfolio company of Canaan Partners
  and added to the API Evangelist network. Peer39 does operate a real REST API — the Peer39 External API at https://app.peer39.com/api/external
  — for creating, updating and deleting Custom Categories (contextual targeting and brand-safety lists of keywords, URLs,
  mobile apps and CTV apps) and syncing them to connected DSPs such as The Trade Desk, Microsoft Advertising/Xandr, Basis,
  Yahoo and Amazon. That API is entirely undocumented in public: there is no developer portal, no API reference page, no OpenAPI
  specification and no published SDK. Credentials are provisioned by a Peer39 account or integration manager who grants the
  "External API" and "RTB Buyer" roles on a named account, and API documentation is distributed as PDFs rather than published
  on the web. A first-party-authored MCP server for the API exists in pre-release on a personal GitHub account and is the
  only public description of the surface.'
url: https://raw.githubusercontent.com/api-evangelist/peer39/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- canaan-partners
x-tier: profiled
x-tier-reason: enrichment-pipeline
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-08-12'
tags:
- Company
- Contextual Advertising
- AdTech
- Brand Safety
- Programmatic Advertising
- Contextual Targeting
- CTV
- MarTech
- Advertising
- Custom Categories
- DSP
apis:
- 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
common:
- type: DomainSecurity
  url: security/peer39-domain-security.yml
- type: LLMsTxt
  url: llms/peer39-llms.txt
- type: Packages
  url: packages/peer39-packages.yml
- type: Conformance
  url: conformance/peer39-conformance.yml
- type: Plans
  url: plans/peer39-plans-pricing.yml
- type: Website
  url: https://www.peer39.com
- type: Blog
  url: https://www.peer39.com/blog
- type: GettingStarted
  url: https://www.peer39.com/onboarding-guide
- type: Login
  url: https://app.peer39.com/login
- type: SignUp
  url: https://www.peer39.com/signup/
- type: Support
  url: https://www.peer39.com/contact-us
- type: TermsOfService
  url: https://www.peer39.com/service-terms
- type: PrivacyPolicy
  url: https://www.peer39.com/privacy-policy/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-08-12'
  status: enriched
  artifacts_added: 12
  pass: local-v1