> Markdown version of https://www.getunleash.io//blog/is-launchdarkly-open-source > For clean Markdown of any blog post, append .md to its URL. > For a site index, see https://www.getunleash.io//llms.txt. # Is LaunchDarkly open source? _Published 2026-07-18 by Alex Casalboni in Product._ - The LaunchDarkly platform is not open source. Current Enterprise subscription terms define an online, cloud-based offering and record that customers receive no entitlement to a copy of the underlying software or code. - LaunchDarkly's SDKs and Relay Proxy are open source under the Apache License 2.0 - Those openly licensed components are not a substitute for the control plane. Neither is useful without a LaunchDarkly account behind it. - Open source is a property of the license covering the control plane, not of a public repository count or a free tier. - When self-hosting, code inspection, and exit rights are requirements rather than preferences, the license on the server itself settles the question. The software in question is the control plane where [feature flags](https://docs.getunleash.io/get-started/what-is-a-feature-flag) are defined and targeted: the system that decides which capabilities are available in production, for which users, and how quickly a release can be pulled back. The confusion starts one layer down. LaunchDarkly's GitHub organization lists hundreds of public repositories, and the SDKs and Relay Proxy carry Apache 2.0 grants. But those clients sit in front of a hosted service for which you need a subscription. ## The Short Answer: No, the Platform Is Not Open Source LaunchDarkly's published pricing page lists Developer, free to start, Foundation, Enterprise, and Guardian. None of those rows is a self-hosted or on-premises edition of the platform. ## What Open Source Requires by Definition The [Open Source Definition](https://opensource.org/osd) maintained by the Open Source Initiative supplies the test: - **Criterion 2 (Source Code)** requires that the program include source code and allow distribution in source as well as compiled form. - **Criterion 3 (Derived Works)** requires that the license allow modifications and derived works. Applied to a hosted feature management platform, the question is whether the code that runs the flag service is available under a license permitting inspection, modification, and redistribution. Criterion 3 is easiest to recognize where it is exercised, in a documented workflow that lets outside developers modify the platform and submit the changes back (as [provided by Unleash](https://docs.getunleash.io/contribute)). ## What LaunchDarkly Publishes Under an Open Source License Releasing SDKs this way is standard practice in feature management: vendors publish [SDK catalogs](https://docs.getunleash.io/sdks) covering server-side and frontend languages under open source terms. ### The SDKs, Under Apache License 2.0 The Go and Python server-side SDKs and the JavaScript client-side SDK each carry an [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0) notice under the copyright line for Catamorphic, Co. (LaunchDarkly's legal entity). GitHub's license detector reports several of those files as "NOASSERTION" or "Other" because they use a short-form notice instead of the full license text, but that’s just a detection artifact. An older Starter and Pro terms document routed SDK rights to that open source license. Current Developer, Foundation, and Enterprise subscription terms do not mention Apache or open source. Those agreements reserve intellectual property rights in the SDK to LaunchDarkly with no open-source carve-out. Therefore, the LICENSE files are the source of the Apache 2.0 conclusion. ### The Relay Proxy, Under Apache License 2.0 LaunchDarkly's Relay Proxy documentation states that the Relay Proxy is an open source project supported by LaunchDarkly, with full source in a GitHub repository. Architecturally it sits between application servers and LaunchDarkly: each server connects to the Relay Proxy, and the Relay Proxy maintains the connection to LaunchDarkly. It relays and caches flag and segment configuration. Evaluation happens in the customer's own infrastructure, in the SDK for server-side SDKs and at the proxy for client-side SDKs. Relay Proxy Enterprise is available only to customers on select plans, with additional security and configuration features for Enterprise and Guardian customers. Those features ship in the same Apache 2.0 binary and are unlocked by plan entitlement, so possessing the source does not confer the capability. ## What Stays Closed: The Flag Management Service ### No Copy of the Underlying Software Flag definitions, targeting-rule authoring, permissions, and audit history run inside LaunchDarkly's infrastructure. For server-side SDKs, targeting-rule evaluation runs in the customer's own process against a locally cached ruleset. For client-side SDKs, evaluation can run at the Relay Proxy or against the hosted service. In every case the rules originate in and are governed by the closed service. The current Enterprise subscription terms reserve to LaunchDarkly all intellectual property rights in the service, the SDK, the documentation, and the underlying technology, including modifications and derivative works. ### What the Terms Restrict Section 3.3 of LaunchDarkly's current Enterprise subscription terms prohibits customers from modifying, copying, or creating derivative works of the service, from reverse engineering it, from accessing it to build a competitive product or service, from using it solely to monitor availability, performance, or functionality or for any benchmarking or competitive purposes intended to be disclosed to a third party, and from providing access to a known competitor. Internal comparative analysis during evaluation is not barred, but publishing those results is. Those clauses are the inverse of OSD criteria 3 and 6: modifications and derived works, and no discrimination against fields of endeavor. ## Why the Distinction Matters for Platform Teams ### Exit Options and Continuity If a contract lapses or renewal terms shift, flag definitions, targeting rules, environments, and change history sit in a service the team cannot stand up independently. Continuity planning has to budget for a control plane migration rather than a source-available fallback. ### Self-Hosting, Data Residency, and Audit LaunchDarkly sells an EU data residency region and a FedRAMP-authorized Federal environment. Both remain LaunchDarkly-hosted instances of the same closed service. A hosted-only control plane can still be assessed through vendor questionnaires, compliance documentation, and contract terms – but source review of the service is not among the options. Platforms built the other way such as Unleash provide and document [hosting models that place the control plane inside a team's own infrastructure](https://docs.getunleash.io/deploy/hosting-options). Hybrid is a middle option: the vendor keeps the API and Admin UI, and the team runs edge components locally. ## If an Open Source Core Is a Requirement Unleash is an [enterprise FeatureOps platform](https://www.getunleash.io/enterprise-feature-management-platform) for autonomous feature management: automated flag creation, governance, and progressive rollout guided by production signals. Its server is published under AGPL-3.0, which puts the core of the platform [under an open source license in its own right](https://www.getunleash.io/open-source). AGPL-3.0 includes a network-use condition: a **modified version offered to others over a network** must make corresponding source available. The documentation sets out [what the open source edition includes and where Enterprise takes over](https://docs.getunleash.io/support/oss-comparison): one project and two environments with community support, without single sign-on or change requests, while self-hosting is available on both editions and the fully managed cloud is Enterprise only. Commercial plans offer [cloud, self-hosted, or hybrid deployment](https://www.getunleash.io/pricing). Self-hosted Enterprise is commercially licensed through license keys even though the open source server underneath carries AGPL-3.0. Hybrid runs Unleash Enterprise Edge, which includes separately licensed enterprise crates alongside the MIT-licensed edge core. ## See an Open Source Core in Practice [Start a free trial](https://www.getunleash.io/plans/enterprise-payg) to run the Unleash server, or [request a walkthrough](https://www.getunleash.io/plans/enterprise) of how the open source edition and Enterprise differ for a given governance profile. ## FAQs ### Is LaunchDarkly open source? No. Components around that hosted service are. ### Are LaunchDarkly's SDKs open source? Yes. Apache 2.0 in the repository LICENSE files. ### Can LaunchDarkly be self-hosted? Not the platform. The Relay Proxy can run in your network as a cache. ### Is the LaunchDarkly Relay Proxy open source? Yes. Apache 2.0. Enterprise features in that binary unlock by plan. ### Does a public GitHub organization make a vendor open source? No. Count the license on the service you would run. ### What does an openly licensed control plane change? A team can review the server and deploy it through the [hosting models](https://docs.getunleash.io/deploy/hosting-options) above, and extend it through the documented [contribution workflow](https://docs.getunleash.io/contribute).