Early access
Feature flags for teams that ship with coding agents.
Merge unfinished work, ship it to production switched off, and turn it on for the right people when it's ready. Your agents can read and change flags too, and any flag Flagger doesn't know about stays off.
Built on the flag system that runs Sandboxer and Transformer in production.
Why flags
Ship to production, not to staging.
The companies behind Flagger ship straight to production. Work that isn't ready is merged and deployed switched off behind a flag, then turned on when it's ready. Coding agents make that pace normal: more changes, merged sooner. Flags keep each one safe to ship.
Off by default
A missing, unknown or not-yet-loaded flag is off, so a deploy never turns on unfinished work by accident.
The server decides
The server checks the flag and enforces it. The browser only gets the flags that are on for that person, never the targeting.
Remove when done
Once a feature is on for everyone and stable, delete the flag and the old code path. Flagger is built to keep that list short.
Running in production today
The core already runs real products.
These parts are live in Sandboxer and Transformer now. Flagger turns them into a service any team can use.
Five states
Off, admins, targets, percent and on. Switching state never loses a target list.
Sticky percentage rollouts
A user who sees a feature at 10% still sees it at 20%. The bucket comes from a hash of the flag and the user.
Targeting
Turn a flag on for named users, verified emails or whole workspaces, plus your admins.
Kill switch
One call sets a flag off and keeps its rules, so you can turn it back on exactly as it was.
Full history
Every change records who made it, when, what it was before and after, and an optional note.
Both paths tested
Test helpers run your code with a flag off and then on, so neither path rots while the flag exists.
Built for agents
Your agents can use flags, safely.
An agent that writes the feature can also put it behind a flag, check its state and roll it out, using the same CLI and API as a person. Flag access needs admin credentials; ordinary customer API keys never get it.
# the CLI an agent or a person uses
flags list
flags set new_billing_page percent --percent 10 --note "start the rollout"
flags target agent_handoff --workspaces ws_8f2a,ws_91c0
flags kill new_billing_page --note "error rate up"In Transformer's production system, admin agents already manage flags over MCP with flags_list, flag_get, flag_set and flag_kill.
In development for early access
What we're adding next.
These aren't live yet. Join the waitlist to try them first and tell us what matters to your team.
Guarded rollouts
Tie a flag to your metrics and step a rollout up automatically, rolling back when errors or latency regress.
Segments and approvals
Reusable audiences, plus a second person's approval before a risky change goes out.
SDKs and experiments
Client libraries for your stack, and experiments that compare variants on the metrics you choose.
Get early access.
We're opening Flagger to a small group of teams first.