detect

Detect repository stack (SDK install)

Before installing anything, you must understand the project. Identify what the project is built with and whether LaunchDarkly is already present.

This skill is nested under LaunchDarkly SDK Install (onboarding); the parent Step 1 is detect. Next: Generate integration plan unless the decision tree sends you elsewhere.

1. Language and framework

Look for the indicator files below (and related root layout), then read the relevant manifests to infer language and framework.

Look for these files to identify the stack:

File Language/Framework package.json JavaScript/TypeScript (check for React, Next.js, Vue, Angular, Express, React Native, Electron, etc.) requirements.txt, pyproject.toml, Pipfile, setup.py Python (check for Django, Flask, FastAPI) go.mod Go (check for Gin, Echo, Fiber, Chi) pom.xml, build.gradle, build.gradle.kts Java/Kotlin (check for Spring, Quarkus, Android) Gemfile Ruby (check for Rails, Sinatra) *.csproj, *.sln, *.fsproj .NET/C# (check for ASP.NET, MAUI, Xamarin, WPF, UWP) composer.json PHP (check for Laravel, Symfony) Cargo.toml Rust (check for Actix, Axum, Rocket) pubspec.yaml Flutter/Dart Package.swift, Podfile, *.xcodeproj Swift/iOS AndroidManifest.xml Android (also check build.gradle for com.android) rebar.config, mix.exs Erlang/Elixir CMakeLists.txt, Makefile (with C/C++ patterns) C/C++ (check for #include patterns) *.cabal, stack.yaml Haskell *.lua, rockspec Lua manifest, *.brs Roku (BrightScript) wrangler.toml Cloudflare Workers (edge SDK) vercel.json with edge functions Vercel Edge (edge SDK)

Read the dependency file to identify the specific framework. For package.json, check both dependencies and devDependencies.

If you cannot identify the language or framework:

D5 -- BLOCKING: Call your structured question tool now.

• question: "I couldn't detect the project's language or framework. Which SDK would you like to use?"

• options: Present the available SDKs from SDK recipes as selectable options.

• STOP. Do not write the question as text. Do not continue until the user selects an option.

2. Package manager

Identify how the project installs dependencies:

Indicator Package Manager package-lock.json npm yarn.lock yarn pnpm-lock.yaml pnpm bun.lockb bun Pipfile.lock pipenv poetry.lock poetry go.sum go modules Gemfile.lock bundler

Use the detected package manager for all install commands. If multiple lock files exist, prefer the one that was most recently modified.

3. Monorepo layout

Some repositories host multiple packages or services. Look for these indicators:

File / pattern Tool or layout pnpm-workspace.yaml pnpm workspaces lerna.json Lerna nx.json Nx turbo.json Turborepo rush.json Rush packages/ directory with multiple package.json files Generic monorepo

When any of these apply, do not assume the repo root is the integration target:

D5 -- BLOCKING: Call your structured question tool now.

• question: "This is a monorepo. Which package, app, or service should I integrate LaunchDarkly into?"

• options: List the discovered packages/apps as selectable options.

• STOP. Do not write the question as text. Do not continue until the user selects an option.

Then run the rest of this detect step -- language, package manager, entrypoint, and SDK search -- in that target directory (and its subtree), not only at the root.

4. Application entrypoint

Find the main file where the application starts. In a monorepo, apply the patterns below within the chosen package after section 3 Monorepo layout . Common patterns:

• Node.js (server): Check package.json "main" field, or look for index.js, server.js, app.js, src/index.ts

• NestJS: Look for src/main.ts or src/main.js

• Python: Look for app.py, main.py, manage.py, wsgi.py, or the [tool.poetry.scripts] section

• Go: Look for main.go or cmd/*/main.go

• Java: Search for public static void main or @SpringBootApplication

• Ruby: Look for config.ru, config/application.rb

• React/Vue/Angular: Look for src/index.tsx, src/main.tsx, src/App.tsx, src/main.ts

• Next.js: App Router -- app/layout.tsx or app/layout.js (root layout). Pages Router -- pages/_app.tsx or pages/_app.js

• React Native: Look for App.tsx, App.js, index.js (with AppRegistry.registerComponent)

• Electron: Check package.json "main"; common paths include main.js or src/main.ts

• JavaScript (browser): Look for index.html, src/index.js, or bundler entry in webpack.config.js / vite.config.ts

• Flutter: Look for lib/main.dart

• Swift/iOS: Look for AppDelegate.swift, SceneDelegate.swift, or @main struct

• Android: Look for MainActivity.java or MainActivity.kt

5a. Classify workspace confidence

After sections 1-4, classify the workspace into one of three states before continuing. This classification determines how the rest of the flow proceeds.

State Meaning Criteria Clear app A runnable application was found Language/framework detected, a real entrypoint exists, dependency manifest is present with application dependencies Unclear / weak evidence Something is present but it does not clearly represent a runnable app Stray or minimal package.json (e.g. only devDependencies, no scripts), isolated config/manifest files, theme or config-only folders, token/fixture JSON, lockfiles without corresponding source, or multiple conflicting indicators with no dominant app structure No app found No recognizable application structure was detected No dependency manifests, no entrypoints, no source files matching known patterns, or the workspace is empty / contains only documentation

Weak evidence must not be treated as confirmation. Examples of weak evidence:

• A package.json with no scripts section and no application source files

• A lone requirements.txt in a directory of data files or notebooks

• Config, theme, or fixture directories with manifests that do not represent a runnable service

• Monorepo roots where the real apps live in subdirectories but none was selected

Branching by state:

Clear app → continue to section 6 (Existing LaunchDarkly SDK) and then SDK confirmation.

Unclear / weak evidence:

D5-UNCLEAR -- BLOCKING: Call your structured question tool now.

• question: "I found some project files, but I'm not confident I've identified the right application to integrate. Can you point me to the correct app folder?"

• context: Briefly describe what you found and why it's ambiguous (e.g., "There's a package.json at the root, but it has no start script and no application source files").

• options:

• Present any candidate folders you detected as selectable options

• "It's somewhere else -- I'll tell you the path"

• "There is no app yet -- help me create a demo"

• STOP. Do not make code changes, install packages, or generate an integration plan until the user confirms the target. Do not continue until the user selects an option.

After the user points to the correct folder, re-run detection (sections 1-4) scoped to that folder.

• No app found:

Tell the user clearly: "I didn't find a runnable application in this workspace." Then offer two paths:

D5-NOAPP -- BLOCKING: Call your structured question tool now.

• question: "I didn't find a runnable application in this workspace. How would you like to proceed?"

• options:

• "Point me to the right folder -- the app is somewhere else"

• "Create a minimal demo app so I can try LaunchDarkly"

• STOP. Do not continue until the user selects an option.

If the user chooses "point me to the right folder," re-run detection scoped to the path they provide. If they choose "create a demo app," create a minimal runnable app in a new subfolder (e.g. launchdarkly-demo/) using the simplest stack you can scaffold (Node.js + Express or a static HTML page are good defaults), then continue detection from that subfolder.

Do not declare onboarding complete unless the app target has been confirmed and the app can actually run.

6. Existing LaunchDarkly SDK

Search the codebase for existing LaunchDarkly usage:

Search for: launchdarkly, ldclient, ld-client, LDClient, @launchdarkly, launchdarkly-

Check:

• Is the SDK already in the dependency file?

• Is there initialization code?

• Is it properly configured or partially set up?

• Are there already feature flag evaluations?