ptuf vs oby-core vs oby-tee

PreToolUseFilter: a generic guardrail layer for coding agents

Core types and Capturer trait for oby — the wire-format and plugin contract shared by oby-hook, oby-tee, and the oby wrapper.

In-pipeline helper for oby. Reads stdin, streams bytes to the wrapper's per-agent unix socket with a JSON header, fail-open. Injected by oby-hook's PreToolUse rewrite to capture stdout/stderr that would otherwise be discarded.