Pi Coding Agent: The Thin Harness Moves Fast Because It Refuses To Own Everything

What Changed

Pi's two-week commit stream is a reminder that a small harness can adapt quickly. It added and removed provider support, changed Codex transport behavior, added a cached websocket transport and SSE fallback, improved auth selection, tightened terminal rendering, added session-directory controls, and kept sanding down export, clipboard, config, and TUI behavior.

The removal of Gemini CLI and Antigravity support is as important as the additions. Pi's thesis is not "integrate everything forever." It is "keep the core small enough that integrations can change without defining the product."

Operator Consequence

Thin harnesses are attractive because they are inspectable and fast-moving. They are also volatile. Operators should not treat a current integration list as durable strategy.

Bitter Consequence

Pi is a useful Bitter agent candidate precisely because it is a harness, not a doctrine. Bitter should record exact Pi version, provider, transport, session directory, extension state, auth source, and terminal mode.

The lesson for Bitter is not to become Pi. The lesson is to keep agent adapters replaceable while the operator loop stays durable.