Flagsmith
Flagsmith is an open-source feature flag, remote configuration and experimentation platform built by Bullet Train Ltd. Teams use it to release features safely, run A/B and multivariate tests, and segment users without redeploying code, across web, mobile and server-side applications. It ships as a hosted cloud service on a global low-latency Edge API, as a private cloud deployment, or self-hosted on the customer's own infrastructure, with the core product open source under BSD-3-Clause. Two public API surfaces back it: a non-secret SDK/Flags API for evaluating flags, and a 615-operation Management API that does everything the dashboard does. Flagsmith is OpenFeature compatible, publishes first-party SDKs for thirteen language ecosystems, and operates a remote MCP server exposing 54 tools to AI agents over OAuth.
Flagsmith publishes 24 API contracts indexed on the APIs.io network, including Flags API, Environments API, Features API, and 21 more. Tagged areas include Feature Flags, Remote Config, Release Management, A/B Testing, and Experimentation.
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, documentation, API reference, getting-started guide, support, pricing, and 40 more developer resources.
What this lets a business do 3
Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →
What people ask Flagsmith 24
The questions people put to an LLM, and the jobs they hand an agent, that Flagsmith's APIs answer — each one linked to the operation that does it. Generated by API Evangelist
Showing 12 of 24 APIs with phrasing — see every API.
Kin Score
Markets this provider is in provisional
The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.
| Market | Position | Depth | Registered MCP server | Declares compatibility |
|---|---|---|---|---|
| Developer Tools | builds-on | 51.7 | - | - |
| Official SDKs on Package Registries | builds-on | 39.0 | - | - |
Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.
APIs 24
Individual APIs this provider publishes, each with its own machine-readable definition.
Flagsmith Flags API
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 use...
flagsmith Environments API
Manage environments within a project. Environments represent deployment stages such as development, staging, and production.
flagsmith Features API
Manage feature flags within a project. Features can be toggled on or off and can have remote configuration values.
flagsmith Identities API
Manage user identities within an environment. Identities represent individual users and their associated traits.
flagsmith Organisations API
Manage organisations within Flagsmith. Organisations are the top-level container for projects, users, and billing.
flagsmith Projects API
Manage projects within an organisation. Projects contain environments and feature flags.
flagsmith Segments API
Manage segments within a project. Segments define groups of users based on traits and rules for targeted flag delivery.
flagsmith Users API
Manage organisation users and their permissions within Flagsmith.
flagsmith Webhooks API
Configure webhooks for environments and organisations to receive notifications about flag changes and audit log events.
Flagsmith Admin dashboard API
Platform hub admin dashboard endpoints.
Flagsmith Analytics API
SDK analytics and telemetry.
Flagsmith Audit API
Access audit logs.
Flagsmith Authentication API
Authentication, MFA, OAuth, and token management.
Flagsmith Experimental API
Experimental endpoints subject to change.
Flagsmith Feature states API
Manage feature states and feature versioning.
Flagsmith Integrations API
Configure third-party integrations (Amplitude, DataDog, Slack, etc.).
Flagsmith MCP API
MCP-compatible endpoints.
Flagsmith Metadata API
Manage metadata fields and model configuration.
Flagsmith O API
The o API from Flagsmith — 1 operation(s) for o.
Flagsmith Onboarding API
Onboarding flows.
Flagsmith Other API
Other endpoints.
Flagsmith Permissions API
Manage user and group permissions across organisations, projects, and environments.
Flagsmith Processor API
The processor API from Flagsmith — 1 operation(s) for processor.
Flagsmith SDK API
SDK endpoints for flags, identities, and traits.
Scroll for all 24
Open Collections 11
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
API Collection
OPEN COLLECTIONFlagsmith Admin API
OPEN COLLECTIONFlagsmith Admin Environments API
OPEN COLLECTIONFlagsmith Admin Environments Features API
OPEN COLLECTIONFlagsmith Admin Environments Flags API
OPEN COLLECTIONFlagsmith Admin Environments Identities API
OPEN COLLECTIONFlagsmith Admin Environments Organisations API
OPEN COLLECTIONFlagsmith Admin Environments Projects API
OPEN COLLECTIONFlagsmith Admin Environments Segments API
OPEN COLLECTIONFlagsmith Admin Environments Users API
OPEN COLLECTIONFlagsmith Admin Environments Webhooks API
OPEN COLLECTIONScroll for all 11
MCP Servers 1
Model Context Protocol servers that expose these APIs to AI agents.
Flagsmith MCP Server
Remote MCP server at mcp.flagsmith.com over streamable HTTP requiring OAuth; 54 tools listed.
MCP SERVERPricing Plans 1
Published pricing tiers and plan structures.
Rate Limits 1
Documented rate limits and quota policies.
Flagsmith Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals for API financial operations.
Flagsmith Finops
FINOPSEvent Specifications 1
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Flagsmith Webhook Events
Flagsmith provides two types of webhooks for receiving event notifications. Environment webhooks automatically send flag evaluations for identified users whenever an identity's ...
ASYNCAPISemantic Vocabularies 1
JSON-LD contexts and semantic vocabularies used across these APIs.
Flagsmith Context
JSON-LDSpectral Rules 2
Spectral governance rulesets for linting and validating these APIs.
Flagsmith — asyncapi rules
SPECTRALFlagsmith — jsonschema rules
SPECTRALOpenAPI Overlays 33
Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.
Flagsmith Analytics Api Phrasing Overlay
GENERATEDFlagsmith Audit Api Phrasing Overlay
GENERATEDFlagsmith Environments Api Overlay
GENERATEDFlagsmith Features Api Overlay
GENERATEDFlagsmith Features Api Phrasing Overlay
GENERATEDFlagsmith Flags Api Overlay
GENERATEDFlagsmith Flags Api Phrasing Overlay
GENERATEDFlagsmith Identities Api Overlay
GENERATEDFlagsmith Mcp Api Phrasing Overlay
GENERATEDFlagsmith Metadata Api Phrasing Overlay
GENERATEDFlagsmith O Api Phrasing Overlay
GENERATEDFlagsmith Organisations Api Overlay
GENERATEDFlagsmith Other Api Phrasing Overlay
GENERATEDFlagsmith Processor Api Phrasing Overlay
GENERATEDFlagsmith Projects Api Overlay
GENERATEDFlagsmith Projects Api Phrasing Overlay
GENERATEDFlagsmith Sdk Api Phrasing Overlay
GENERATEDFlagsmith Segments Api Overlay
GENERATEDFlagsmith Segments Api Phrasing Overlay
GENERATEDFlagsmith Users Api Overlay
GENERATEDFlagsmith Users Api Phrasing Overlay
GENERATEDFlagsmith Webhooks Api Overlay
GENERATEDFlagsmith Webhooks Api Phrasing Overlay
GENERATEDScroll for all 33
JSON Schema 1
Standalone JSON Schema definitions for this provider's data models.
Flagsmith Feature Flag
JSON SCHEMASecurity Posture 4
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes governing access to this provider's APIs.
Agentic Access 1
Recommended x-agentic-access execution contracts for AI agents.
Resources
Get Started 4
Portal, sign-up, and the first successful call
Documentation 3
Reference material describing how the API behaves
Agent Surfaces 5
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 7
Pagination, idempotency, versioning, errors, and events
Scroll for all 7
Build 6
SDKs, sample code, and the tooling you integrate with
Access & Security 7
Authentication, authorization, and security posture
Scroll for all 7
Operate 6
Status, limits, changes, and where to get help
Commercial 5
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 1
Properties that don't map to a standard resource type
Source (apis.yml)
Work with this as data
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