General Code Style & Formatting

My build system is bun.
My testing framework is vitest.
I am building AI agents using LangGraph in TypeScript and Node.js.
I am using the Vercel AI SDK for model interactions.
When I ask about programming concepts (e.g., "What is a hook?"), give me a direct and clear explanation.
I am using TypeScript for development.
I am using Node.js for runtime.
I am using bun for development.
I am using dotenv for environment variables.
I am using pdf-parse for PDF parsing.
I am using biome for code formatting and linting.
Follow the shared services architecture.
Follow the DRY and SOLID principles.
Do not make any changes to the shared services.

# General Code Style & Formatting
- Use English for all code and documentation.
- Always declare the type of each variable and function (parameters and return value).
- Avoid using any.
- Create necessary types.
- Use JSDoc to document public classes and methods.
- Don't leave blank lines within a function.
- One export per file.

# Naming Conventions
- Use PascalCase for classes.
- Use camelCase for variables, functions, and methods.
- Use kebab-case for file and directory names.
- Use UPPERCASE for environment variables.
- Avoid magic numbers and define constants.

# Functions & Logic
- Keep functions short and single-purpose (<20 lines).
- Avoid deeply nested blocks by:
- Use early returns.
- Extract logic into utility functions.
- Use higher-order functions (map, filter, reduce) to simplify logic.
- Use arrow functions for simple cases (<3 instructions), named functions otherwise.
- Use default parameter values instead of null/undefined checks.
- Use RO-RO (Receive Object, Return Object) for passing and returning multiple parameters.

# Data Handling
- Avoid placing validation inside functions—use classes with internal validation instead.
- Prefer immutability for data:
- Use readonly for immutable properties.
- Use as const for literals that never change.
- Use type guards to validate data types.
- Prefer 'for...of' loops over 'forEach' for iteration.

# Effect
- Use Effect.flatMap for async operations.
- Use Effect.logDebug for debugging.
- Use Effect.logWarning for warnings.
- Use Effect.logError for errors.
- Use Effect version 3.16
- Avoid using the (_) pattern in Effect.gen.

You are an expert in Typescript, Node.js, vitest and Bun.
Use Typescript version 5.8.

Code Style and Structure
- Write concise, technical Typescript code with accurate examples.
- Use function and declaritive programming patterns consistent with Effect.ts.
- Prefer iteration and modularization over code duplication.
- Use descriptive variable names with auxilary verbs (e.g. isLoading, hasError).
- Structure files: exported components, subcomponents, helpers, static content, types.

Typescript Usage
- Use Typescript for all code; prefer interfaces over types.
- Avoid enums; use maps instead.
- Use the "function" keyword for pure functions.
- Never move or delete biome directives
- Make sure all answers are typesafe
- prefer Typescript interfaces over Typescript types

Syntax and Formatting
- Avoid unneeded semicolons.
- Use declaritive TSX

Effect.ts Usage
- Use Effect version 3.16
- Use the Effect.Service pattern for dependency injection
- Use Effect.gen for complex operations
- Use pipe() for chaining operations
- Handle errors with Effect.catchAll or Effect.mapError
- Use Layer.provide for providing dependencies
- Prefer Effect pattern over traditional async/await except when interfacing with non-Effect code

Tools
- Use Bun as you package manager.  Do not use npm, pnpm or yarn.
- Use Vitest for testing.
- Don't use Vitest for mocking test data.  Build custom mocks instead.

Do not hallucinate.

When testing an agent or a node in an agent, use the shared configuration service. 

for ANY question about LangGraph, use the langgraph-docs-mcp server to help answer -- 
+ call list_doc_sources tool to get the available llms.txt file
+ call fetch_docs tool to read it
+ reflect on the urls in llms.txt 
+ reflect on the input question 
+ call fetch_docs on any urls relevant to the question
+ use this to answer the question