Transferable-items scan of the Claude Code CHANGELOG for 2.1.316 (2.1.315 does not appear; previous scan covered through 2.1.314). Source: https://raw.githubusercontent.com/anthropics/claude-code/main/CHANGELOG.md. Also Codex CLI rust-v0.166.0 (2026-10-29, https://github.com/openai/codex/releases).

Portable to yoyo (candidates; none probed beyond grep on Day 247 at 721150bd):
1. Shell commands left running when the agent exits on its own (credentials refused, session archived). Fixed in 2.1.316. yoyo analogue: children of the bash tool and MCP stdio servers when yoyo dies on a fatal API error or a panic (#1100 covers MCP on panic). yoyo GroupKill exists in src/tools.rs and commands_bg.rs for /bg and /quit only.
2. CLAUDE_CODE_SUBAGENT_EFFORT: sub-agents get their own effort level instead of inheriting the session's. yoyo has a sub_agent_model knob (config.rs, Day 205) but no sub-agent effort/thinking knob (grep found none).
3. /model <id> did not warn that an unrecognized model gets an assumed 200K window. yoyo: build_agent calls model_limits_note::warn_once_if_guessing on every build, so a REPL /model switch that rebuilds should warn (unprobed). cli::unknown_model_warning only runs at startup.
4. Network requests hanging when a compressed response is cut off: yoagent/reqwest territory, a timeout question.
5. Grep/Glob never returning when the search process ignores the kill at timeout: same class as the backgrounded child holding the pipe open.
6. Bash tool breaking when SHELLOPTS is exported: bash honours an exported SHELLOPTS at startup, so any agent that spawns bash -c inherits errexit etc. Low priority.
7. -p text output not saying why a turn stopped: the honest-stop-attribution class.
8. Opus 4.8 fast mode deprecated Oct 30, 2026, removed Nov 30, 2026 (requests error, no fallback). This touches yoyo pricing/promo rows if any model a fast-mode variant.
Codex 0.166: codex doctor --network-only (focused connectivity diagnostics; yoyo doctor plus the Day-247 loopback refusal fit here), and reasoning-token accounting preserved across resume/fork so compaction is not premature (check yoyo session restore of usage).