- Always use Yarn as the package manager - never use npm or other package managers - Run all general commands (e.g. not for starting a server) from the repository root using Turbo orchestration (yarn build, yarn lint, yarn format) - Before creating new utilities or shared functions, search in packages/shared/src to see if one already exists - When importing from the shared package, use the @open-swe/shared namespace with specific module paths - Follow strict TypeScript practices - the codebase uses strict mode across all packages - Use ESLint and Prettier for code quality - run yarn lint:fix and yarn format before committing - Console logging is prohibited in the open-swe app (ESLint error) - use the `createLogger` function to create a new logger instance instead - Build the shared package first before other packages can consume it (yarn build from the root handles this automatically via turbo repo) - Follow existing code patterns and maintain consistency with the established architecture - Include as few inline comments as possible This is a Yarn workspace monorepo with Turbo build orchestration containing three main packages: **apps/open-swe**: LangGraph agent application - Core LangChain/LangGraph agent implementation with TypeScript - Contains three graphs: programmer, planner, and manager (configured in langgraph.json) - Uses strict ESLint rules including no-console errors **apps/web**: Next.js 15 web interface - React 19 frontend with Shadcn UI components (wrapped Radix UI) and Tailwind CSS - Modern web stack with TypeScript, ESLint, and Prettier with Tailwind plugin - Serves as the user interface for the LangGraph agent **packages/shared**: Common utilities package - Central workspace dependency providing shared types, constants, and utilities - Exports modules via @open-swe/shared namespace (e.g., @open-swe/shared/open-swe/types) - Must be built before other packages can import from it - Contains crypto utilities, GraphState types, and open-swe specific modules **Root Configuration**: - turbo.json: Build orchestration with task dependencies and parallel execution - .yarnrc.yml: Yarn 3.5.1 configuration with node-modules linker - tsconfig.json: Base TypeScript configuration extended by all packages **Package Manager**: Use Yarn exclusively (configured in .yarnrc.yml) **Installation Process**: - Run `yarn install` from the repository root - this handles all workspace dependencies automatically **Key Dependencies**: - LangChain ecosystem: @langchain/langgraph, @langchain/anthropic for agent functionality - Next.js 15 with React 19 for web interface - Shadcn UI (wrapped Radix UI) and Tailwind CSS for component library and styling - TypeScript with strict mode across all packages - Jest with ts-jest for testing framework **Workspace Structure**: Dependencies are managed on a per-package basis, meaning dependencies should only be installed in their specific app/package. Individual packages reference the shared package via @open-swe/shared workspace dependency. **Testing Framework**: Jest with TypeScript support via ts-jest preset and ESM module handling **Test Types**: - Unit tests: *.test.ts files (e.g., take-action.test.ts in __tests__ directories) - Integration tests: *.int.test.ts files (e.g., sandbox.int.test.ts) **Running Tests**: - `yarn test` - Run unit tests across all packages - `yarn test:int` - Run integration tests (apps/open-swe only) - `yarn test:single ` - Run a specific test file **Test Configuration**: - 20-second timeout for longer-running tests - Environment variables loaded via dotenv integration - ESM module support with .js extension mapping - Pass-with-no-tests setting for CI/CD compatibility **Writing Tests**: Focus on testing core business logic, utilities, and agent functionality. Integration tests should verify end-to-end workflows. Use the existing test patterns and maintain consistency with the established testing structure.