flagsmith

Flagsmith is an open-source feature flag and remote configuration platform that helps developers manage feature flags across web, mobile, and server-side applications.

flagsmith publishes 9 APIs on the APIs.io network, including Flags API, Environments API, Features API, and 6 more.

The flagsmith catalog on APIs.io includes 1 event-driven AsyncAPI specification, 1 JSON-LD context, and 2 Spectral governance rulesets.

flagsmith’s developer surface includes authentication, engineering blog, and 6 more developer resources.

🌐 Visit website 📡 Source on GitHub

44.4/100 developing ▬ flat Agent 43/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6

AccessFreemiumSelf serve⚡ Free to try

9 APIs

Kin Score

Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6

Composite quality — 44.4/100 · developing

Contract Quality 19.1 / 25

Developer Ergonomics 2.6 / 20

Commercial Clarity 7.9 / 20

Operational Transparency 4.8 / 13

Governance 5.0 / 12

Discoverability 5.0 / 10

Agent readiness — 43/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 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

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/flagsmith: 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 9

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

Rate Limits 1

Documented rate limits and quota policies.

Flagsmith Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

JSON Schema 1

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

Documentation 1

Reference material describing how the API behaves

JSONSchema

JSONSchema

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

JSONLD

JSONLD

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Company 2

The organization behind the API

LinkedIn

Blog

Blog

Source (apis.yml)

aid: flagsmith
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/flagsmith.png
url: https://raw.githubusercontent.com/api-evangelist/flagsmith/refs/heads/main/apis.yml
apis:
- aid: flagsmith:flags-api
  name: Flagsmith Flags API
  tags:
  - Edge
  - Feature Flags
  - Flags
  - Remote Config
  - SDKs
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  baseURL: https://edge.api.flagsmith.com
  humanURL: https://docs.flagsmith.com/clients/rest
  properties:
  - url: https://docs.flagsmith.com/clients/rest
    type: Documentation
  - url: openapi/flagsmith-flags-api-openapi.yml
    type: OpenAPI
  description: The Flagsmith Flags API is the public-facing REST API that client-side and server-side SDKs use to retrieve
    feature flag values and remote configuration for environments and users. It uses a non-secret Environment Key for authentication
    and is designed to be fast, scalable, and publicly accessible. The Edge API endpoint at edge.api.flagsmith.com serves
    requests from AWS Lambda functions running in data centers near the client, providing low-latency global access to flag
    evaluations.
- aid: flagsmith:flagsmith-environments-api
  name: flagsmith Environments API
  description: Manage environments within a project. Environments represent deployment stages such as development, staging,
    and production.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Environments
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-environments-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
- aid: flagsmith:flagsmith-features-api
  name: flagsmith Features API
  description: Manage feature flags within a project. Features can be toggled on or off and can have remote configuration
    values.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Features
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-features-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
- aid: flagsmith:flagsmith-identities-api
  name: flagsmith Identities API
  description: Manage user identities within an environment. Identities represent individual users and their associated traits.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Identities
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-identities-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
- aid: flagsmith:flagsmith-organisations-api
  name: flagsmith Organisations API
  description: Manage organisations within Flagsmith. Organisations are the top-level container for projects, users, and billing.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Organisations
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-organisations-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
- aid: flagsmith:flagsmith-projects-api
  name: flagsmith Projects API
  description: Manage projects within an organisation. Projects contain environments and feature flags.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Projects
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-projects-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
- aid: flagsmith:flagsmith-segments-api
  name: flagsmith Segments API
  description: Manage segments within a project. Segments define groups of users based on traits and rules for targeted flag
    delivery.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Segments
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-segments-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
- aid: flagsmith:flagsmith-users-api
  name: flagsmith Users API
  description: Manage organisation users and their permissions within Flagsmith.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Users
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-users-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
- aid: flagsmith:flagsmith-webhooks-api
  name: flagsmith Webhooks API
  description: Configure webhooks for environments and organisations to receive notifications about flag changes and audit
    log events.
  humanURL: https://docs.flagsmith.com/clients/rest
  baseURL: https://edge.api.flagsmith.com
  tags:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/flagsmith-webhooks-api-openapi.yml
  - type: Documentation
    url: https://docs.flagsmith.com/integrating-with-flagsmith/flagsmith-api-overview/admin-api
  - type: AsyncAPI
    url: asyncapi/flagsmith-webhooks-asyncapi.yml
common:
- type: AgenticAccess
  url: agentic-access/flagsmith-agentic-access.yml
- type: DomainSecurity
  url: security/flagsmith-domain-security.yml
- type: Authentication
  url: authentication/flagsmith-authentication.yml
- type: GitHubOrganization
  url: https://github.com/Flagsmith
- type: LinkedIn
  url: https://www.linkedin.com/company/flagsmith
- type: JSONLD
  url: json-ld/flagsmith-context.jsonld
- type: JSONSchema
  url: json-schema/flagsmith-feature-flag-schema.json
- url: https://flagsmith.com/blog
  type: Blog
modified: '2026-05-19'
description: Flagsmith is an open-source feature flag and remote configuration platform that helps developers manage feature
  flags across web, mobile, and server-side applications.

flagsmith

APIs 9

Open Collections 2

Pricing Plans 1

Rate Limits 1

FinOps 1

Event Specifications 1

Semantic Vocabularies 1

Spectral Rules 2