flaggy — fast, OpenFeature-compatible feature flags

flaggy v0.1 · open source · self-hostable

Feature flags that don't suck. Fast, OpenFeature-compatible, self-hostable. Drop in the SDK of your choice and ship.

Try the demo →Open dashboard →GitHub $ self-host

← user · role · % · A/B · all on the hot path →

drop in

From `git clone` to live flag in three steps.

01step 1
Self-host
One Postgres + one binary. Migrations on first boot.
02step 2
Drop in the SDK
OpenFeature provider for Node or Go. Local eval after init.
03step 3
Ship
Targeting + rollouts + A/B from the dashboard. ~0ms p99.

live demo

Watch a flag resolve.

A real cascade of rules against the context you paste in. First match wins, deterministic FNV-1a bucketing on the rest.

context

targetingKey

attrs.role

rules

#0usertargetingKey ∈ ["alice", "carol"]→on

#1rolerole ∈ ["internal"]→on

#2percentage25% of role=beta (FNV-1a bucketed)→on

#3defaultdefault variant→off

result

flag

new-checkout

value

variant

on

reason

TARGETING_MATCH · r1

try `bob` · role=`free` · or hit ⌘K

what it does

The targeting you want, on the hot path.

User targeting

Allowlist specific users by id. First-match wins.

Role targeting

Match on role attributes carried in the eval context.

Percentage rollouts

Deterministic FNV-1a bucketing. Stable across toggles.

Weighted A/B

Split traffic across variants by weight. Same hash family.

OpenFeature-native

Drop-in provider, not a custom SDK. Server-side, ~0ms p99.

Self-hostable

One binary, one Postgres. No external deps in OSS mode.

SDKs

One eval engine, three implementations.

Same golden vectors run against the Go API, the Node SDK, and (soon) the browser SDK. Drift between any two fails the test.

TypeScript

shipped

pnpm add @flaggy/openfeature-provider

OpenFeature.setProviderAndWait(
  new FlaggyProvider({ baseUrl, token })
);
const client = OpenFeature.getClient();
await client.getBooleanValue("new-checkout", false, ctx);

Go

shipped

go get github.com/flaggy/flaggy/sdks/openfeature-provider-go

provider := flaggy.NewProvider(flaggy.ClientOptions{
    BaseURL: baseURL, Token: token,
})
provider.Init(ctx)
openfeature.SetProvider(provider)
client := openfeature.NewClient("my-app")
v, _ := client.BooleanValue(ctx, "new-checkout", false, ec)

Browser

soon

// @flaggy/openfeature-web-provider

// client-side bundle, signed snapshot, ETag fallback

Python