Featureflip

Archive a flag (soft-hide, evaluation stops serving it). Reversible with restore_flag. Archive dependents first: refused with FLAG_HAS_DEPENDENTS while another live flag lists this one as a prerequisite, so archive those flags (blockedBy in find_stale_flags / list_removal_candidates) first. Refused with FLAG_RECENTLY_EVALUATED while live traffic is still evaluating the flag, because archiving makes every caller fall back to its own hardcoded default — normally that means the code removal has merged but not deployed yet, and the refusal clears itself once it has.

Create a feature flag. type is one of Boolean|String|Number|Json. Boolean flags get true/false variations automatically; for other types pass initialVariations. The flag is created in every environment of the project (disabled).

PERMANENTLY delete a flag across all environments. Fails with FLAG_HAS_DEPENDENTS if other flags use it as a prerequisite. Prefer archive_flag unless the flag must be fully removed.

action=test queues one synthetic flag.toggled event to this subscription alone; action=redeliver (deliveryId from list_webhook_deliveries) re-sends a finished delivery, restarting its retry schedule. Delivery is asynchronous: read list_webhook_deliveries for the outcome. Both are refused for a disabled subscription, and redeliver for a delivery that is still Pending. Requires an Admin token. A 404 on every webhook call means webhooks are not enabled for the organization.

Find flags that look ready for code cleanup: not updated in N days AND either enabled in every environment (verify rollout is complete before removing — per-rule percentage ramps are not inspected) or disabled in every environment (dead — remove flag and code path). A flag whose expiry date (set_flag_expiry) has passed is always a candidate, however recently it was edited; if it is on in some environments and off in others its reason is past-expiry, meaning the owner has to decide which way to fold it. A project can give its temporary flags a default lifetime, so a flag with no date of its own can still be past expiry. Every result carries expiresAtUtc (the date set on the flag), effectiveExpiresAtUtc (the date in effect, from the flag or its project default), expirySource (explicit, project-default, or null), expired and owner (null when unowned). Flags marked permanent (kill switches, ops toggles) are never listed. Pass owner to see one person's stale flags ("me" for your own) or "none" for the unowned ones. Every result also carries blockedBy: the live flags that still list it as a prerequisite, which have to be removed and archived before it ([] when none). blockedBy is null when the server did not classify the flag as a removal candidate, which means unknown, not unblocked. A flag that other live flags list as a prerequisite has to be removed LAST, dependents first: archiving it while a dependent still names it makes that dependent fail its prerequisite check and serve its off variation, so archive_flag refuses it with FLAG_HAS_DEPENDENTS. Checks at most 50 candidates per call, expired flags first.

What a flag actually served in ONE environment over the last 7, 30 or 90 days: total evaluations, the split by variation, and which rule (or fallthrough, off, prerequisite, error) served what. Percentage-rollout rules include their configured weights and a sample-ratio check; rollout.flagged=true means the served split is statistically off the configured weights. A live rollout rule is always listed, with count 0 and no variations when it served nothing. rollout.unreached is set when a live rollout rule got no evaluations while the flag's rules got 100 or more: usually the context lacks rollout.bucketBy, or an earlier rule or the conditions catch the traffic. These are evaluation counts, NOT unique users. Counts come from SDK-reported events, so zero means no evaluations were reported, not necessarily no traffic.

Compact cross-environment view of one flag: enabled state, strategy, default variation, and prerequisites per environment.

Get one feature flag with its variations and metadata, including its owner (null when unowned). Address by flag key or id.

Get one user segment (its conditions, id, and metadata) by key or id.

Get a flag's current targeting configuration (enabled flag + ordered rules) in one environment.

List the environments of a project (e.g. development, staging, production).

List feature flags in a project. Filter with search (key/name substring), tag, type, archived, owner. Each flag carries its owner ({id, email, name}, or null when unowned). Paginated via cursor.

List projects in the Featureflip organization. Paginated: pass cursor from next_cursor to continue.

List the flags the server is confident can be removed from code, the same list the Featureflip flag cleanup GitHub Action works from. Each item has key, reason, status (Dead or Stale), treatment (true = keep the on-branch, false = keep the off-branch) and blockedBy: the live flags that still list it as a prerequisite. Only remove a flag whose blockedBy is empty. A flag that other live flags list as a prerequisite has to be removed LAST, dependents first: archiving it while a dependent still names it makes that dependent fail its prerequisite check and serve its off variation, so archive_flag refuses it with FLAG_HAS_DEPENDENTS. staleness "dead" (the default) returns only dead flags, "stale" adds stale ones. Paginated via cursor.

List the SDK keys of one environment: id, name, type, last four characters, and whether each is active. The full key is never listed; it is shown once, when manage_sdk_key creates it.

List reusable user segments in a project. Segments are referenced from targeting rules via userSegmentId.

List one subscription's delivery attempts, most recent first. status is Pending (awaiting an attempt, backing off, or in flight), Succeeded or DeadLettered; lastResponseStatusCode and lastError explain a failure. Paginated via cursor. Requires an Admin token. A 404 on every webhook call means webhooks are not enabled for the organization.

List the organization's outbound webhook subscriptions (url, event/project/environment filters, enabled state, failure count, signing secret ids — never secret values), plus availableEventTypes: the event types a subscription can filter on. Empty filter lists mean "all". Paginated via cursor. Requires an Admin token. A 404 on every webhook call means webhooks are not enabled for the organization.

Create an environment in a project, or change its name, color or sort order. action=create needs key + name; action=update needs environment and changes only the fields you pass. The key is immutable. Environments cannot be deleted from here. A new environment needs an SDK key before apps can use it (manage_sdk_key).

Create a project, or change its name/description. action=create needs key + name; action=update needs project and changes only the fields you pass (description: "" clears it). The key is immutable. Projects cannot be deleted from here.

Manage an environment's SDK keys. action=create needs name + type and returns the full key ONCE (ServerSide for backend SDKs, ClientSide for browser/mobile). action=rename needs sdkKey and changes only the fields you pass. action=revoke needs sdkKey and stops the key working immediately; apps still using it lose flag updates. To rotate: create a new key, deploy it, then revoke the old one.

Manage reusable user segments, which targeting rules reference by userSegmentId. action=create needs key + name (+ conditions); action=update needs segment and changes only the fields you pass (conditions replaces the whole list; description: "" clears it); action=delete needs segment. On update, pass ifMatch (the etag from get_segment) so a change someone made since you read it is not overwritten. ifMatch is rejected on create and delete: the API cannot make those conditional.

Edit a single targeting rule instead of replacing them all with update_targeting. action=add needs rule (appended last); action=update needs ruleId + rule and changes only the fields you pass (conditionGroups replaces the rule's groups; to clear rolloutPercentage or userSegmentId use update_targeting); action=remove needs ruleId; action=reorder needs ruleIds, every existing rule id exactly once, in the new order. Rule ids come from get_targeting.

Manage a flag's variations. action=add requires key + value; action=update/remove require variationId (get ids via get_flag). Removing a variation fails with VARIATION_HAS_DEPENDENTS if other flags depend on it.

action=create requires name + url and returns the signing secret. action=update/delete/rotate_secret/retire_secret require id. provider (create only, default GenericHttp) is the destination type: a Slack incoming webhook URL (https://hooks.slack.com/services/...) needs provider: "Slack", which posts readable channel messages; a subscription's provider can never change. update changes only the fields you pass and keeps the rest; pass an empty list to widen that filter back to "all". projects take project keys or ids; environments take "<project>/<environment>" keys (e.g. "web/production") or ids. eventTypes come from list_webhooks → availableEventTypes. create and rotate_secret return a secret that is NEVER shown again: relay it to the user verbatim so they can store it. Slack doesn't verify signatures, so a Slack subscription's secret is unused and rotate_secret is refused for one. rotate_secret adds a new active secret while the old one keeps signing; retire_secret (secretId from list_webhooks) removes one and is refused for the last active secret. A project-restricted service token must list at least one project, all in its scope. Requires an Admin token. A 404 on every webhook call means webhooks are not enabled for the organization.

Restore a previously archived flag.

Set how many days a temporary flag with no expiry date of its own lives before it counts as expired, or pass days: null to remove the default. Advisory only: evaluation never changes. Pass preview: true first to see how many flags would newly be, or stop being, past expiry without changing anything. Setting a value is refused with FEATURE_NOT_ENABLED when the organization's plan lacks it; removal is always allowed. The current value is defaultFlagLifetimeDays in list_projects.

Set the date a flag is expected to be removed by, or pass expiresAtUtc: null to clear it. Expiry is advisory: evaluation never changes. Once the date passes, find_stale_flags reports the flag as expired. expiresAtUtc takes a date (2026-12-31), which means the end of that day in UTC, the same as picking it in the dashboard, or a full ISO-8601 timestamp, which is stored exactly. Refused with EXPIRY_IN_PAST for a time that has already passed (today's date is allowed), with FEATURE_NOT_ENABLED while flag expiration is not enabled for the organization, and with PERMANENT_FLAG_HAS_EXPIRY on a permanent flag (make it temporary first with set_flag_permanent). Clearing is always allowed.

Name the person responsible for a flag, or pass owner: null to leave it unowned. owner is the email of an active member of the organization, or "me" for the token's own user (needs a personal access token). The owner gets the flag's cleanup notices; evaluation never changes. Refused with OWNER_NOT_MEMBER for an email that is not an active member, and with PLAN_FEATURE_UNAVAILABLE below the Pro plan. Clearing is always allowed.

Mark a flag permanent (a kill switch, ops toggle or entitlement gate that is meant to stay), or pass permanent: false to make it temporary again. Permanent flags are never listed as removal candidates or by find_stale_flags; evaluation never changes. Marking is refused with PERMANENT_FLAG_HAS_EXPIRY while the flag has an expiry date (clear it first with set_flag_expiry and expiresAtUtc: null), with FEATURE_NOT_ENABLED while permanent flags are not enabled for the organization, and on an archived flag. Making a flag temporary is always allowed.

Enable or disable a flag in ONE environment. Affects live evaluation immediately — double-check the environment.

Update flag name/description/tags/clientSideVisible. Changes only the fields you pass and keeps the rest; pass description: "" to clear it. Key and type are immutable. Use toggle_flag / update_targeting for behavior changes. Pass ifMatch (the etag from get_flag) to refuse the write if the flag changed since you read it.

Update a flag's per-environment serving config: defaultVariationId (served on fallthrough, required), strategy (SingleVariation | PercentageRollout | TargetedRollout — only SingleVariation is currently supported at the environment level), and prerequisites. Percentage rollouts are configured on targeting rules via update_targeting.

REPLACE all targeting rules of a flag in one environment (full PUT — rules not included are removed). Rules are evaluated in order. Get the current rules first with get_targeting. Pass ifMatch (the etag from get_targeting) so rules someone else changed meanwhile are not overwritten.

Create a Boolean feature flag and get back the SDK code snippet to guard the new code path with it. Returns the snippet only — apply the edit yourself. The flag starts DISABLED in every environment; enable it with toggle_flag when ready.