Function Calling in TypeScript/Node.js

TypeScript function calling: JSON Schema from types

Step-by-step guide to generating JSON Schema from TypeScript types for type-safe LLM function calling in Node.js, with runnable code and tests.

July 17, 20263 min read

Testing tool-calling flows in TypeScript with Vitest

This hands-on guide to testing tool-calling flows in TypeScript with Vitest walks through unit, mock, and integration tests for building real LLM apps.

Streaming function calls in Node.js with async iterators

A practical guide to building streaming function calls nodejs async iterators pipelines with TypeScript, covering parsing, execution, and verification for LLM APIs.

July 17, 20263 min read

Node.js function calling with Claude's Messages API

Hands-on tutorial for nodejs claude messages api function calling: build a TypeScript agent that invokes local tools via Anthropic's Messages API step by step.

July 17, 20261 min read

Function calling with LangChain.js: a TypeScript tutorial

A hands-on TypeScript tutorial for langchainjs typescript function calling: define typed tools, bind to a chat model, and run the agent loop.

July 17, 20263 min read

Function calling in Next.js API routes with GPT-4o

Step-by-step tutorial for implementing GPT-4o function calling inside Next.js API routes, with runnable TypeScript code and expected outputs.

API integrationGuide

Error handling patterns for function calling in Node.js

Practical error handling patterns for function calling in Node.js: structured retries, validation, tool isolation, and graceful degradation for LLM apps.

July 17, 20264 min read

Building an LLM tool-calling agent in TypeScript

Hands-on tutorial for building an LLM tool-calling agent in TypeScript: set up the OpenAI SDK, define JSON Schema tools, and run a ReAct loop with real code.

Building a multi-tool agent in TypeScript and Node.js

Hands-on tutorial to build a multi-tool agent in TypeScript and Node.js with function calling against OpenAI-compatible LLM endpoints, including runnable code.

Type-safe function calling in Node.js with Zod schemas

Build type-safe function calling in Node.js with Zod: convert schemas to JSON Schema, validate LLM tool calls, and run a reliable agent loop.

July 16, 20264 min read

Function calling with TypeScript and the OpenAI SDK

A hands-on tutorial for implementing TypeScript OpenAI SDK function calling in Node.js, from tool schema definition to executing local functions.

July 16, 20263 min read