Flags

Ship code that's switched off, then turn it on for yourself, for one customer, for the pro plan, or for ten percent of everyone. Percentage rollouts are deterministic: the same person always gets the same answer, so they don't flicker between versions.

Add Flags Read the guide

Rules on any attribute

Match on equality, lists, ranges or substrings of any attribute you pass in, such as plan, role, country or app version.

Stable percentage rollouts

Rollouts use a hash of the flag and the user, so each person keeps the same variant as you widen it.

Several flags in one call

Evaluate every flag a page needs in a single request, on the server or at the edge.

Kill switches

Turn off a broken feature from the dashboard. The change takes effect on the next request.

ExperimentsIn preview

Assign variants and compare them using the events Observe already collects.

In your code.

Roll out to the pro plan, then to a fifth of everyone else.

JSON

{
  "key": "editor.v2",
  "default_value": false,
  "rules": [
    { "conditions": [{ "attr": "plan", "op": "eq", "value": "pro" }], "value": true },
    { "conditions": [{ "attr": "user_id", "op": "percent", "value": 20 }], "value": true }
  ]
}

Better with.

What Flags does once another system is switched on in the same app.

Identity
Target a flag by role, organization or the plan someone is on.
Billing
Roll a feature out to one plan before you put it on the pricing page.
Observe
Compare error rates and events between the people with a flag on and those without.

Endpoints.

The main routes. The API reference lists every parameter and response.

POST /v1/flags
GET /v1/flags
PATCH /v1/flags/:key
POST /v1/flags/evaluate

Included in the plan.

Flags is part of every account: free within hard limits, then included in the $29 plan that covers every system and every app.

Included
Unlimited flags. 10 million evaluations.
Beyond that
$0.50 per extra million evaluations.

Next: Models All pricing