flagKey; the product name is control point.
v1 exposes exactly those two capabilities. The SDKs do not ship OpenFeature providers, and they do not expose releases, exposures, signals, or capabilities. Guardrails are evaluated by fw-server and the Fireweave console during rollouts; the SDK has no guardrails API.
If you are using a coding agent to integrate Fireweave, start with For coding agents.
Onboarding
Account, CLI, coding-agent plugin, then ship your first change behind a control point.
SDK quickstart
Install, initialize with a required mode, evaluate a control point, register a target, and shut down.
SDKs
Seven language bindings share one surface: a mode-selected adapter, a runtime, and a client withcontrolPoints (cased per language) plus registerTarget.
Node.js, Bun, and Deno
@fireweaveai/server-sdk 2.3.0 — initFireweave, controlPoints, registerTarget. Node >=20.20.Python
fireweave 2.3.0 — init_fireweave, control_points, register_target. Python >=3.10.Go
…/sdks/go/v2 v2.3.0 — Init, ControlPoints(), RegisterTarget. The /v2 suffix is required.Java
ai.fireweave:fireweave-sdk 2.3.0 — Fireweave.init, controlPoints(), registerTarget(). Java 11+.Browser
@fireweaveai/web-sdk 2.3.0 — synchronous reads, registerTarget / identify, fw_public_ keys.Rust
crates.io
fireweave 2.3.0 — init_fireweave, control_points, register_target. Rust 1.75+.Compatibility
Seven-language surface, 65×7 conformance aggregate, and the capability matrix.
Package index
Registry names, versions, and what is actually installable.
What you can do
- Evaluate boolean, string, number, and object decisions through nine methods. A read returns your default on failure and does not throw.
- Register targets once at login (
registerTarget/ language equivalent) so targeting rules can match durable properties. - Choose a mode at init:
remote(fw-server) orlocal(seeded in-process map).modeis required and never inferred.
The product noun is control point.
flagKey remains the key name on the wire, in canonical envelopes, in conformance fixtures, and in capabilities.features.flags. The onboarding guide covers the product path — plugin skills and gradual rollouts — while these pages are the SDK reference.Architecture and concepts
How it works
Evaluate and register — the runtime path from your app to fw-server.
Architecture
Client → Runtime → Adapter, lifecycle states, and the fw-server paths.
Core concepts
Control points, targeting, adapters, and decisions.
Migrate to v1
Package rename, required
mode, and the retired OpenFeature / extension surface.Production, troubleshooting, reference
Configuration and auth
Explicit
apiUrl / apiKey (or language equivalent). The SDK reads no environment variables.Lifecycle
Initialize, READY / STALE, shutdown. Reads after close return defaults.
Errors
Fifteen error kinds and how reads degrade to your default.
Troubleshooting
Defaults that look like “off,” missing targeting keys, and boot configuration errors.
HTTP API
POST /v1/flags/evaluate, POST /v1/capture, POST /v1/targets/register.CLI
Command-line tools for Fireweave projects.