Summary
Digest of two coding-agent CLI releases — Claude Code 2.1.309 (2026-10-22) and Codex CLI 0.163.0 (2026-10-15) — with each change mapped onto the equivalent behavior (or gap) in yoyo, a competing agent-builder tool. The through-line is operational hardening: prompt/context loading limits, sandbox enforcement that survives session boundaries, correct truncation of tool output, consistent permission inheritance across sub-agents, and auditable events for blocked tool calls. Codex's release is comparatively feature-oriented (steering a running turn, parallel read-only tools, searchable config).
Key Points
- Context loading: Oversized nested
CLAUDE.mdfiles now load only their beginning instead of triggering repeated compaction. yoyo's Day 237 probe shows it loads a 2.16 MBCLAUDE.mdinto--print-system-promptwhole (2,162,802 bytes) with no stderr note — it only warns once the prompt exceeds the entire context window (agent_builder::system_prompt_token_budget). - Sandbox durability: On Linux, sandbox write denials no longer lapse when a background command outlives the session. A Bash command truncated by a full disk now reports the failure and names the affected folder.
- Session migration: On a self-hosted runner, when a session moves, Claude sees an interrupted tool call explicitly marked
"outcome unknown"rather than silently losing it. - Truncation bugs: Long tool-output previews no longer cut through an emoji (character-boundary truncation); yoyo has the same bug class filed as #250.
- Permission inheritance: Split-pane teammates now inherit the leader's tool-deny and
--toolsrules. yoyo analogue: sub-agents and/spawnworkers must inherit--deny-dirand disallowed-tool settings. - MCP and sandbox integrity: A disabled MCP server is no longer revived by a later permission prompt; sandboxed commands can no longer modify the
--mcp-configfile. - Auditability: Claude Code 2.1.307 introduced the OTel event, emitted whenever a rule, hook, or sandbox stops a tool call. yoyo's counterpart is .