guides
Guides
Plain answers to the questions teams ask about feature flags, and about feature flags when AI agents write and ship the code. Each guide starts with the answer, then the detail, with real commands from Flagger.gg's CLI, MCP tools and SDKs.
Guides
What is a feature flag?
A feature flag is a switch in your code that turns a feature on or off, for everyone or chosen users, without a deploy. How flags work, with examples.
Feature flags for AI coding agents
Why every change an AI coding agent ships should land behind a flag, and how agents create, roll out and kill flags with scoped tokens and an audit log.
Let Claude Code, Codex and Cursor ship behind flags
Set up Claude Code, Codex or Cursor to ship behind feature flags: a scoped agent token, Flagger.gg's MCP server, and instructions to create and kill flags.
An MCP server for feature flags, used safely
Flagger.gg's MCP server gives agents 11 feature-flag tools, hosted or on stdio. Tools follow token scope, writes need a note, there's no approve tool.
Kill switches: roll back a bad release in seconds
A kill switch is a feature flag you turn off at once, no deploy. Kill a bad release in seconds with Flagger.gg's CLI, MCP tool or console, then revert.
Percentage rollouts and sticky bucketing
How to roll a feature out to a percentage of users so each user keeps the same answer as you widen it: sticky hash bucketing, with Go and Node examples.
Trunk-based development with AI agents
With AI agents shipping many changes in parallel, feature flags replace long-lived branches: each agent merges small changes to main and ships them dark.
Feature flags vs a staging environment
Staging tests a copy of production; flags test the real thing with a few real users first. When teams skip staging and ship to production behind a flag.
Testing both sides of a flag
Test code behind a feature flag with the flag on and off. Flagger.gg's Go and Node SDKs include bothFlagStates, withFlag and setFlagOverride helpers.
Flag cleanup and flag debt
Flag debt is old flags left in code after a feature is fully on. How to find stale feature flags, remove them safely, and archive them in Flagger.gg.
Comparisons
How Flagger.gg compares with other flag tools, fairly, with links to each vendor's own docs. All comparisons
LaunchDarkly vs Flagger.gg
LaunchDarkly vs Flagger.gg, fairly: LaunchDarkly for experiments, broad SDKs and rich targeting; Flagger.gg when AI agents ship your code in Go or Node.
Datadog feature flags vs Flagger.gg
Datadog Feature Flags (from its 2025 purchase of Eppo) tie flags to Datadog's metrics. Flagger.gg is a standalone flag service with agent access over MCP.
Unleash, Flagsmith and PostHog alternatives
Unleash, Flagsmith and GrowthBook are open source and self-hostable; PostHog bundles flags with analytics. How they compare with Flagger.gg.