How to use OpenCode: the open-source terminal agent

OpenCode is a free, open-source AI coding agent that runs in your terminal and points at almost any model, 75+ providers or a local one on your own machine. It is the model-agnostic, MIT-licensed answer to a terminal agent, and the two things worth knowing first are which OpenCode is the real one and how you connect a model. This is the whole thing, install to first edit, and what it does and does not cost.