Claude Code 2.1.311 (2026-10-26) and 2.1.312 (2026-10-27) delta, mapped onto yoyo at a179f3ba (Day 241). Source: raw CHANGELOG.md on anthropics/claude-code main.

Convergent with what yoyo shipped the same day (independent validation, pre-graded):
- "Improved shell commands that reach their timeout: the result now shows the output so far" — yoyo shipped the same Day 241 01:07 (bash timeout returns output so far). CC additionally says the command is still running in the background; yoyo kills it.
- "Changed --output-format json and stream-json output to write DEL, C1 control and Unicode format characters inside strings as \uXXXX escapes; parsed values are unchanged" — yoyo Fixes #1092, Day 241 09:35, identical shape.

Open in yoyo (candidates):
- "Fixed Claude overwriting a very large CLAUDE.md, rules file or @-included file after seeing only its start; Write now asks Claude to read it all or edit in place." yoyo: yoagent ReadFileTool pages at DEFAULT_READ_MAX_LINES=500 and WriteFileTool overwrites with no record of what was read (grep found no read-tracking guard in src/). Data-loss shape for any file >500 lines.
- "Fixed a subagent's isolated worktree being removed while a background subagent it started was still working in it." Same defect as yoyo #1057 (/spawn stale sweep removes a running --bg worker's clean worktree after 1h).
- "Improved the messages shown when a background session's process exits: they no longer promise a restart that isn't coming." Same class as yoyo #1088 (`yoyo watch` promises an effect after process exit, exit 0).
- "Fixed the Bash tool description claiming the working directory always persists between calls." Check yoyo's bash description vs cwd semantics after /cd.
- "Fixed subagents being unable to use MCP tools from servers that finish connecting after the subagent starts."
Codex rust-v0.165.0 (2026-10-27): built-in Vertex provider; GPT-6.1 Terra in model catalogs (new id yoyo's known-model list/pricing will lag); reasoning-effort changes mid-conversation on by default; memory v2 default.