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 9 APIs on the APIs.io network, including Flags API, Environments API, Features API, and 6 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 39 more developer resources.
Kin Score
APIs 9
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.
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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
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 API Rules
SPECTRALFlagsmith API Rules
SPECTRALJSON 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
Source (apis.yml)
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Every provider here is available over the APIs.io API and to AI agents over MCP.