flow

Static type checking for React code across DOM and native platforms. Four renderer options cover standard DOM, browser-specific code, React Native, and Fabric environments Run yarn flow with optional renderer argument; use yarn flow-ci for comprehensive but slower checks Reports type errors with file locations to help identify and fix issues quickly Watch for common pitfalls: missing renderer specification, unexamined $FlowFixMe suppressions, and incorrect type imports

npx skills add https://github.com/facebook/react --skill flow

Download ZIP GitHub

Flow Type Checking

Arguments:

$ARGUMENTS: Renderer to check (default: dom-node)

Renderers

Renderer	When to Use
`dom-node`	Default, recommended for most changes
`dom-browser`	Browser-specific DOM code
`native`	React Native
`fabric`	React Native Fabric

Instructions

Run yarn flow $ARGUMENTS (use dom-node if no argument)
Report type errors with file locations
For comprehensive checking (slow), use yarn flow-ci

Common Mistakes

Running without a renderer - Always specify or use default dom-node
Ignoring suppressions - Check if $FlowFixMe comments are masking real issues
Missing type imports - Ensure types are imported from the correct package

More skills from facebook

For the full explanation and rationale, see doc/GCSafeCoding.md .

app-review-prep

Prepare a Meta app for App Review — checks current status, outstanding requirements, granted privileges, and submission history. Use before submitting an app…

Monitor API health for a Meta app — check rate limits, call volume, and API deprecations. Use to diagnose throttling, plan capacity, or prepare for API version…

Troubleshoot webhook issues for a Meta app — inspect active subscriptions, identify misconfiguration, and send test payloads to verify delivery. Use when…

api-integration

Guide a developer through setting up a Meta API integration from scratch — discovers the right APIs, fetches setup guides, authentication requirements,…

Set up webhooks for a Meta app end-to-end — discover available topics, subscribe to fields, and verify with a test payload. Use when configuring webhooks for…

Test UI system (PanelUI, ScreenSpace) against the poke example using the iwsdk CLI.

Inspect and compare feature flag states across React release channels. View all flags across channels (www, www-modern, canary, next, experimental, rn variants) or compare specific channels with --diff Output formats include default table view, CSV export, and cleanup status grouping Flag states indicated by symbols: enabled (✅), disabled (❌), variant testing (🧪), profiling-only (📊) Common pitfall: __VARIANT__ flags are tested in both states on www; use --diff to spot meaningful...