Developer Builds AI Support Agent in ~100 Lines of TypeScript Without Any Framework

Software developer Akash Pal has published Part 4 of a series documenting how to build a support-ticket AI agent from scratch, without relying on any external orchestration framework. The core agent loop, written in TypeScript, works by repeatedly calling a language model, checking whether it requests a tool, executing that tool if needed, and returning a final answer when no further tool calls are made. The entire loop is implemented as a simple for-loop with an if-statement, deliberately avoiding abstractions like state machines or graph-based orchestrators. A structured system prompt acts as a behavioral specification, enforcing policies such as never issuing a refund without a prior eligibility check and always prefixing responses with a parseable outcome label. Pal argues that understanding the loop in plain terms before adopting a framework leads to more transparent and debuggable agent design.