Tutorials 14 min read· 4 Aug 2026· By Tutorials
Building an agent with tool loops — end to end
A 200-line agent that browses the web, writes code, and reports back. Complete source.
Agents are just a while loop with tool calls. The interesting part is what tools you provide and how you constrain the loop.
The scaffold#
python
TOOLS = [
{"type": "function", "function": {"name": "search_web", "parameters": {...}}},
{"type": "function", "function": {"name": "read_page", "parameters": {...}}},
{"type": "function", "function": {"name": "write_report", "parameters": {...}}},
]The loop#
See the full function calling patterns post for the canonical shape.
Cap iterations. Log everything. Ship the trace to your dashboard for every run — you'll thank yourself in a month.