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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 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.

Flagsmith Flags API is one of 9 APIs that flagsmith publishes on the APIs.io network, described by a machine-readable OpenAPI specification.

Tagged areas include Edge, Feature Flags, Flags, Remote Config, and SDK. The published artifact set on APIs.io includes API documentation and an OpenAPI specification.

This API exposes 1 operation across 1 path, and defines 3 schemas. It is described by OpenAPI 3.1.0, at version 1.0.

Requests are made against a single base URL, https://api.flagsmith.com/api/v1.

1 operations 1 paths 3 schemas 1 GET

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.1.0
API Version
1.0
Base URL
https://edge.api.flagsmith.com
Authentication
API Key
Terms of Service
Resource Areas
1

Authentication & Security 1

Flagsmith Flags API declares 1 security scheme for authenticating requests. An API key is passed in the header as Authorization (apiKeyAuth). By default, every request must be authenticated.

  • apiKeyAuth — A secret Organisation API Token prefixed with 'Api-Key'. For example, 'Api-Key your-token-here'. This token should never be exposed in client-side code.

Paths & Operations 1

Across 1 path, the API surfaces 1 operation — 1 GET. Each is listed below with its method, path, parameters, and response codes.

Flags 1

Retrieve feature flags for an environment. Returns the current state of all feature flags including their enabled status and values.

GET
/flags/
List all flags for an environment
listFlags 1 param → 200401

Schemas 3

The contract defines 3 schemas that model the data the API accepts and returns. The most detailed are Flag (7 properties), Feature (7 properties), Error (1 property). Each schema is shown below with its type and property counts.

Feature
object
A feature definition containing metadata about the feature flag including its name, type, and default configuration.
7 properties
Flag
object
A feature flag object containing the feature definition, its enabled state, and any associated value for the environment.
7 properties
Error
object
An error response from the API
1 property

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

flagsmith-flags-api-openapi.yml Raw ↑

Other APIs flagsmith publishes across the network.

flagsmith Environments API
flagsmith Features API
flagsmith Identities API
flagsmith Organisations API
flagsmith Projects API
flagsmith Segments API
flagsmith Users API
flagsmith Webhooks API
Where this information came from

This is an independent, third-party profile of Flagsmith Flags API, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.

The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.

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