# LaunchDarkly API

**Provider:** LaunchDarkly
**Category:** developer
**Base URL:** `https://app.launchdarkly.com/api/v2`
**Auth:** api-key — `Authorization: YOUR_ACCESS_TOKEN`
**Rate Limit:** 100 requests/sec (sustained) · Burst up to 200 req/sec
**Free Tier:** No
**Pricing:** from $10/mo (subscription)
**Docs:** https://apidocs.launchdarkly.com

## Description

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.

## Endpoints

| Method | Endpoint | Description |
|--------|----------|-------------|
| GET | `https://app.launchdarkly.com/api/v2/flags/{projectKey}` | List all feature flags in a project |
| POST | `https://app.launchdarkly.com/api/v2/flags/{projectKey}` | Create a new feature flag |
| PATCH | `https://app.launchdarkly.com/api/v2/flags/{projectKey}/{featureFlagKey}` | Update a flag (toggle on/off, change targeting rules) |
| GET | `https://app.launchdarkly.com/api/v2/projects` | List all projects in the account |
| GET | `https://app.launchdarkly.com/api/v2/environments/{projectKey}` | List environments (dev, staging, prod) |
| POST | `https://app.launchdarkly.com/api/v2/experiments/{projectKey}/{envKey}` | Create an A/B test experiment |

## Authentication

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

```
Authorization: YOUR_ACCESS_TOKEN
```

## Sample Request

```bash
# 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

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

## Pricing Details

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

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*Source: [API Map](https://apimap.dev/apis/launchdarkly/) — CC BY 4.0*