LaunchDarkly

launchdarkly Server-Side Streaming API

Server-Sent Events streaming endpoints for server-side SDKs to receive real-time flag updates.

GitHub OpenAPI

Operations 2

Each operation below carries the questions people ask an LLM about it and the instructions they give an agent to run it. Generated by API Evangelist overlay

GET /all Stream all flag and segment data to a server · Stream all flag data (server-side) #
Ask an LLM
“How does a server SDK get real-time updates for flags and segments together?”
“Can I open one stream that carries all flag data?”
Tell an agent
Open the server-side stream of all flag data.
Stream flags and segments to my server in real time.
GET /flags Stream only flag updates to a server · Stream flag updates (server-side) #
Ask an LLM
“Can I stream just flag changes without segment data?”
“Which server-side stream sends flags only?”
Tell an agent
Open a flags-only server-side stream.
Stream flag updates without segments.

Documentation

📖
Documentation
https://launchdarkly.com/docs/api
📖
Documentation
https://launchdarkly.com/docs/sdk/relay-proxy

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/launchdarkly/refs/heads/main/openapi/launchdarkly-server-side-streaming-api-openapi.yml

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OpenAPI Specification

launchdarkly-server-side-streaming-api-openapi.yml Raw ↑ 
openapi: 3.2.0
info:
  title: LaunchDarkly Relay Proxy Server-Side Streaming API
  description: The LaunchDarkly Relay Proxy is a small Go application that connects to the LaunchDarkly streaming API and proxies that connection to SDK clients within an organization's network. It exposes endpoints for status monitoring, flag evaluation, and SDK streaming that mirror the LaunchDarkly service endpoints. Instead of each server making outbound connections to LaunchDarkly's streaming service, multiple servers connect to the local Relay Proxy which maintains a single upstream connection.
  version: '8.0'
  contact:
    name: LaunchDarkly Support
    url: https://support.launchdarkly.com
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
servers:
- url: http://localhost:8030
  description: Default Relay Proxy instance
tags:
- name: Server-Side Streaming
  description: Server-Sent Events streaming endpoints for server-side SDKs to receive real-time flag updates.
paths:
  /all:
    get:
      operationId: streamAllFlags
      summary: Stream all flag data (server-side)
      description: Establishes a Server-Sent Events (SSE) stream that delivers real-time flag data updates for server-side SDKs. Requires an SDK key in the Authorization header.
      tags:
      - Server-Side Streaming
      security:
      - sdkKeyAuth: []
      responses:
        '200':
          description: SSE stream delivering flag data updates.
          content:
            text/event-stream:
              schema:
                type: string
                description: Server-Sent Events stream with put and patch events.
        '401':
          description: Unauthorized. Invalid SDK key.
        '503':
          description: Service unavailable. Flag data not yet available.
  /flags:
    get:
      operationId: streamFlagsOnly
      summary: Stream flag updates (server-side)
      description: Establishes a Server-Sent Events (SSE) stream that delivers only flag updates (not segments) for server-side SDKs.
      tags:
      - Server-Side Streaming
      security:
      - sdkKeyAuth: []
      responses:
        '200':
          description: SSE stream delivering flag updates.
          content:
            text/event-stream:
              schema:
                type: string
                description: Server-Sent Events stream with flag events.
        '401':
          description: Unauthorized. Invalid SDK key.
        '503':
          description: Service unavailable.
components:
  securitySchemes:
    sdkKeyAuth:
      type: apiKey
      in: header
      name: Authorization
      description: Server-side SDK key for authenticating with the Relay Proxy.
    mobileKeyAuth:
      type: apiKey
      in: header
      name: Authorization
      description: Mobile SDK key for authenticating with the Relay Proxy.
externalDocs:
  description: Relay Proxy Documentation
  url: https://launchdarkly.com/docs/sdk/relay-proxy