name: feature-switch description: Feature switch system guide for gating new user-facing features behind feature flags
Feature Switch Skill
This skill documents the feature switch system and provides step-by-step instructions for adding new feature switches. All new user-facing features must be gated behind a feature switch for gradual rollout.
When to Use
A feature switch is required when adding:
- New UI pages, sections, or sidebar navigation items
- New API endpoints exposed to users or agents
- New integrations (connectors, Slack, Telegram, etc.)
- New zero token capabilities
A feature switch is not required for:
- Internal refactors or code cleanup
- Test infrastructure changes
- Build/CI configuration
- Bug fixes to existing features
- Documentation updates
How to Add a Feature Switch
Step 1: Add a key to the enum
File: turbo/packages/core/src/feature-switch-key.ts
Add a new entry to FeatureSwitchKey:
export enum FeatureSwitchKey {
// ... existing keys
MyFeature = "myFeature",
}
Step 2: Register the switch
File: turbo/packages/core/src/feature-switch.ts
Add an entry to the FEATURE_SWITCHES record:
[FeatureSwitchKey.MyFeature]: {
maintainer: "you@vm0.ai",
enabled: false,
enabledOrgIdHashes: STAFF_ORG_ID_HASHES, // optional: staff-only access
},
Configuration options:
| Field | Type | Description |
|---|---|---|
maintainer |
string |
Email of the responsible person |
enabled |
boolean |
true = on for everyone, false = off by default |
enabledUserHashes |
string[] |
FNV-1a hashes of allowed user IDs |
enabledEmailHashes |
string[] |
FNV-1a hashes of allowed emails |
enabledOrgIdHashes |
string[] |
FNV-1a hashes of allowed org IDs |
Common default states:
enabled: false— fully hidden until manually enabled via Lab pageenabled: false+enabledOrgIdHashes: STAFF_ORG_ID_HASHES— staff-only (most common for new features)enabled: true— on for everyone (use when feature is ready for GA)
Step 3: Gate the feature in application code
Choose the pattern that matches where your feature is consumed.
Server-side (API routes)
import { isFeatureEnabled, FeatureSwitchKey } from "@vm0/core";
// In route handler:
if (!isFeatureEnabled(FeatureSwitchKey.MyFeature, { userId, orgId })) {
return createErrorResponse("FORBIDDEN", "Feature not available");
}
Client-side (Platform UI)
import { FeatureSwitchKey } from "@vm0/core";
import { featureSwitch$ } from "../../signals/external/feature-switch.ts";
// In component:
const features = useLastResolved(featureSwitch$);
const showMyFeature = features?.[FeatureSwitchKey.MyFeature] ?? false;
// Conditional rendering:
{showMyFeature && <MyFeatureComponent />}
Sidebar navigation gating
In turbo/apps/platform/src/views/zero-page/zero-sidebar.tsx, add a featureGate to the sidebar item:
{
id: "my-feature",
label: "My Feature",
icon: MyIcon,
featureGate: FeatureSwitchKey.MyFeature,
}
Connector gating
In turbo/packages/core/src/contracts/connectors.ts, add featureFlag to the connector config:
myConnector: {
label: "My Connector",
featureFlag: FeatureSwitchKey.MyConnector,
// ...
}
Zero token capability gating
In turbo/apps/api/src/signals/auth/tokens.ts, add to CONDITIONAL_CAPABILITIES:
const CONDITIONAL_CAPABILITIES: ReadonlyMap<ZeroCapability, FeatureSwitchKey> =
new Map([
// ... existing entries
["my-feature:write", FeatureSwitchKey.MyFeature],
]);
Key Files
| File | Role |
|---|---|
turbo/packages/core/src/feature-switch-key.ts |
Enum of all feature switch keys |
turbo/packages/core/src/feature-switch.ts |
Registry and evaluation logic |
turbo/apps/platform/src/signals/external/feature-switch.ts |
Client-side reactive state with override layers |
turbo/apps/platform/src/views/zero-page/zero-sidebar.tsx |
Sidebar nav items with featureGate |
turbo/packages/core/src/contracts/connectors.ts |
Connector type definitions with featureFlag field |
turbo/apps/api/src/signals/auth/tokens.ts |
Token capability gating |
Override Layers
Evaluation has two layers (lowest to highest priority):
- Core registry — static config in source code, evaluated against
userId/email/orgIdhashes. - Per-user DB overrides — row in
user_feature_switcheskeyed by(orgId, userId). Written via the Lab page toggles orwindow._vm0.featureSwitches.myFeature = true(both callPOST /api/zero/feature-switches). Cleared via the Lab page "Reset all" button (DELETE /api/zero/feature-switches).
The same two-layer resolution applies on the server: route handlers that call isFeatureEnabled(..., { userId, orgId, overrides }) pass overrides loaded via loadFeatureSwitchOverrides(orgId, userId).
There is no client-only layer. window._vm0.featureSwitches requires auth and persists across refreshes; there is no device-local override.