Technology · Ebook

OpenFeature: The Open Standard for Feature Flagging

by Shriira Press

OpenFeature is the CNCF open standard for feature flagging — a vendor-neutral API and SDK that decouples your application code from any specific flag provider, so you can use, switch, or mix providers without changing code. This free book teaches it from the ground up: the feature flagging fragmentation problem and what OpenFeature is, feature flagging and progressive delivery concepts, OpenFeature's architecture (the spec, SDKs, and pluggable providers), flag evaluation (the typed standard API, safe defaults, evaluation details), providers (the pluggable backends and ecosystem), evaluation context and targeting (per-user evaluation), hooks and events (standard extensibility for logging and telemetry), flagd and evaluation architectures (the open-source backend, in-process vs remote), adoption and migration (integrating, migrating off a vendor SDK, switching providers), and using OpenFeature in practice. Ten focused chapters with clear diagrams that make vendor-neutral flagging concrete — code to a standard API, keep the provider a swappable detail, and gain freedom, consistency, and no lock-in: the OpenTelemetry of feature flags.

Contents

1. 1Preface
2. 2Chapter 1 — What OpenFeature Is
3. 3Chapter 2 — Feature Flagging and Progressive Delivery
4. 4Chapter 3 — OpenFeature Architecture
5. 5Chapter 4 — Flag Evaluation
6. 6Chapter 5 — Providers
7. 7Chapter 6 — Evaluation Context and Targeting
8. 8Chapter 7 — Hooks and Events
9. 9Chapter 8 — flagd and Evaluation Architectures
10. 10Chapter 9 — Adoption and Migration
11. 11Chapter 10 — OpenFeature in Practice