Introduction
Feature flags for teams that ship often. Deploy code dark, roll it out by percentage, roll it back in one command.
Flagrship is a REST API, a CLI, and SDKs for JavaScript and Python. The flag is the release mechanism: your code ships through CI as usual and does nothing until you say so. Rollback is one command and every SDK picks it up within a poll.
terminal
$ flagrship create new-checkout✓ Created new-checkout in staging — OFF$ flagrship rollout new-checkout 25✓ Rolled out new-checkout in staging — ON 25%$ flagrship rollback new-checkout✓ Rolled back new-checkout in staging — OFFQuickstart
Install the CLI and flip your first flag in about five minutes.
CLI reference
Every command, every option, and how the config file works.
JavaScript SDK
2 KB, zero dependencies, synchronous evaluation.
Python SDK
Stdlib only, thread-safe, same buckets as Node.
What it does
- Percentage rollouts — users hash into 100 buckets; raise the number and more of them see the feature, never in a different order.
- Rollback as undo — restores the state before the last change and logs itself, so a second rollback undoes the first.
- Locks — an admin locks a flag with a reason. Every mutation returns 409 until it is unlocked.
- Audit trail — every change writes who, when, before and after in the same transaction.
How it is built
| Piece | What it is |
|---|---|
| API | Fastify on Postgres. Environment comes from the API key, never a parameter. |
| CLI | A thin client over the API. One command, one call, one audit row. |
| SDKs | Fetch config once, poll with an ETag, evaluate in memory. Never a network call per check. |
| Bucketing | MurmurHash3 over flagKey:userId, inside the SDK. The API never sees a user ID. |