What is the LaunchDarkly API base URL?

The LaunchDarkly API base URL is https://app.launchdarkly.com/api/v2

LaunchDarkly API — Base URL, Auth & Endpoints

LaunchDarkly is the leading feature management platform. Its REST API lets you create and toggle feature flags, define targeting rules (percentage rollouts, user segments, custom attributes), manage environments (dev/staging/production), set up experiments and A/B tests, view flag evaluation metrics, and automate flag lifecycle management. Used for safe deployments, gradual rollouts, kill switches, and personalization at scale.

Quick Reference

Base URL https://app.launchdarkly.com/api/v2 Auth type API Key Header Auth header Authorization: YOUR_ACCESS_TOKEN Rate limit 100 requests/sec (sustained) · Burst up to 200 req/sec Pricing from $10/mo Free quota 14-day free trial Documentation https://apidocs.launchdarkly.com Endpoint status Live — HTTP 200 — endpoint is accessible1.49s (checked Mar 29, 2026) Builder score B 65% builder-friendly

Pricing

Latency

Depth

Authentication

Generate an Access Token in LaunchDarkly Account Settings → Authorization. Pass it in the Authorization header (no Bearer prefix).

Authorization: YOUR_ACCESS_TOKEN

Pricing

Model subscription Starting price from $10/mo Free quota 14-day free trial

Starter $10/seat/mo: feature flags, individual targeting. Pro $20/seat/mo: flag rollouts, experiments, metrics. Enterprise: custom, includes SSO and advanced audit logs.

Key Endpoints

Method	Path	Description
GET	`/flags/{projectKey}`	List all feature flags in a project
POST	`/flags/{projectKey}`	Create a new feature flag
PATCH	`/flags/{projectKey}/{featureFlagKey}`	Update a flag (toggle on/off, change targeting rules)
GET	`/projects`	List all projects in the account
GET	`/environments/{projectKey}`	List environments (dev, staging, prod)
POST	`/experiments/{projectKey}/{envKey}`	Create an A/B test experiment

Sample Request

# Toggle a feature flag ON in production
curl "https://app.launchdarkly.com/api/v2/flags/my-project/new-checkout-flow" \
  -H "Authorization: $LD_ACCESS_TOKEN" \
  -H "Content-Type: application/json; domain-model=launchdarkly.semanticpatch" \
  -X PATCH \
  -d '{"instructions":[{"kind":"turnFlagOn","environmentKey":"production"}]}'

Sample Response

{
  "key": "new-checkout-flow",
  "name": "New Checkout Flow",
  "kind": "boolean",
  "environments": {
    "production": { "on": true, "lastModified": 1710000000000 }
  }
}