Ninetailed

Ninetailed (now Contentful Personalization) is an API-first personalization and experimentation platform for content-rich applications. It provides a REST-based Experience API for managing visitor profiles, defining audience segments, running A/B tests, and delivering personalized experiences at the edge. SDKs are available for JavaScript, React, Next.js, Node.js, and React Native.

Ninetailed publishes 2 APIs on the APIs.io network: Events API and Profiles API. Tagged areas include Personalization, Experimentation, A/B Testing, Audience Segmentation, and Feature Flags.

The Ninetailed catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Ninetailed’s developer surface includes documentation, engineering blog, pricing, changelog, and 12 more developer resources.

🌐 Visit website 📡 Source on GitHub

44.6/100 developing ▬ flat Agent 22/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessPaid

1 APIs

Personalization Experimentation A/B Testing Audience Segmentation Feature Flags Headless CMS Edge Computing Content Management

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 44.6/100 · developing

Contract Quality 14.7 / 23

Developer Ergonomics 1.3 / 18

Access Clarity 9.5 / 18

Operational Transparency 6.2 / 12

Contract Governance 1.1 / 11

Discoverability 6.2 / 9

Create-or-Update Ergonomics 2.2 / 10

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/ninetailed: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 2

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

Ninetailed Events API

Batch event ingestion endpoints for profile enrichment.

Ninetailed Profiles API

Operations for creating, reading, updating, and deleting visitor profiles.

Open Collections 3

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

Ninetailed Experience Events API

OPEN COLLECTION

Ninetailed Experience Events Profiles API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Ninetailed Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Ninetailed Rate Limits

4 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Ninetailed Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Ninetailed Context

10 classes · 39 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Ninetailed API Rules

5 rules · 3 warnings 2 info

SPECTRAL

JSON Schema 3

Standalone JSON Schema definitions for this provider's data models.

NinetailedEvent

7 properties

JSON SCHEMA

NinetailedExperience

4 properties

JSON SCHEMA

NinetailedProfile

9 properties

JSON SCHEMA

Examples 3

Example request and response payloads for these APIs.

Batch Events Sync

4 fields

EXAMPLE

Create Profile

4 fields

EXAMPLE

Update Profile Identify

4 fields

EXAMPLE

Security Posture 3

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

Ninetailed Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Ninetailed Vulnerability Disclosure

security.txt · contact published

SECURITY

Ninetailed Trust Center

SOC 2, ISO 27001

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Ninetailed Agentic Access

6 operations · 5 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrg

GitHubOrg

Access & Security 3

Authentication, authorization, and security posture

TrustCenter

TrustCenter

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

StatusPage

StatusPage

ChangeLog

ChangeLog

RateLimits

RateLimits

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

Website

Website

LinkedIn

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Source (apis.yml)

aid: ninetailed
name: Ninetailed
description: Ninetailed (now Contentful Personalization) is an API-first personalization and experimentation platform for
  content-rich applications. It provides a REST-based Experience API for managing visitor profiles, defining audience segments,
  running A/B tests, and delivering personalized experiences at the edge. SDKs are available for JavaScript, React, Next.js,
  Node.js, and React Native.
type: Index
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/ninetailed.png
url: https://raw.githubusercontent.com/api-evangelist/ninetailed/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.23'
tags:
- Personalization
- Experimentation
- A/B Testing
- Audience Segmentation
- Feature Flags
- Headless CMS
- Edge Computing
- Content Management
apis:
- aid: ninetailed:ninetailed-events-api
  name: Ninetailed Events API
  description: Batch event ingestion endpoints for profile enrichment.
  humanURL: https://www.contentful.com/developers/docs/ninetailed/experience-api/
  baseURL: https://experience.ninetailed.co/v2
  tags:
  - Event
  tags_raw:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/ninetailed-events-api-openapi.yml
  - type: Documentation
    url: https://www.contentful.com/developers/docs/ninetailed/experience-api/
- aid: ninetailed:ninetailed-profiles-api
  name: Ninetailed Profiles API
  description: Operations for creating, reading, updating, and deleting visitor profiles.
  humanURL: https://www.contentful.com/developers/docs/ninetailed/experience-api/
  baseURL: https://experience.ninetailed.co/v2
  tags:
  - Profiles
  properties:
  - type: OpenAPI
    url: openapi/ninetailed-profiles-api-openapi.yml
  - type: Documentation
    url: https://www.contentful.com/developers/docs/ninetailed/experience-api/
common:
- type: AgenticAccess
  url: agentic-access/ninetailed-agentic-access.yml
- type: TrustCenter
  url: security/ninetailed-trust-center.yml
- type: VulnerabilityDisclosure
  url: security/ninetailed-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/ninetailed-domain-security.yml
- type: Website
  url: https://www.contentful.com/products/personalization/
- type: Documentation
  url: https://www.contentful.com/developers/docs/ninetailed/
- type: GitHubOrg
  url: https://github.com/ninetailed-inc
- type: LinkedIn
  url: https://www.linkedin.com/company/ninetailed
- type: Blog
  url: https://medium.com/@Ninetailed
- type: Pricing
  url: https://www.contentful.com/pricing/
- type: StatusPage
  url: https://ninetailedstatus.com/
- type: X
  url: https://x.com/ninetailedhq
- type: ChangeLog
  url: https://www.contentful.com/developers/docs/ninetailed/ninetailed-changelog/
- type: Plans
  url: plans/ninetailed-plans-pricing.yml
- type: RateLimits
  url: rate-limits/ninetailed-rate-limits.yml
- type: FinOps
  url: finops/ninetailed-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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