Claude Code: Subagent Fork Default, Cross-Session Mentions, GitLab Marketplace repo
The latest Claude Code release (circa Aug 25-26, 2026) makes subagent forking on by default so fork subagents inherit the full conversation and prompt cache, adds cross-session @mention so Claude can reach another live session by name via SendMessage, and extends plugin marketplace support to bare GitLab repo URLs including nested subgroups.
What it does for you: Subagent fork default is the most operationally significant change: any agent spawned with subagent_type fork now gets the full conversation context and prompt cache automatically, which cuts redundant context setup across every multi-agent Axion flow. The @mention feature lets Hermes bridge sessions communicate with each other directly by name, which is a building block for multi-agent orchestration without external message queues. GitLab plugin marketplace support means YY can host private skills in a GitLab repo and have Claude Code resolve them the same way as GitHub repos.
In practice: A well-packed release. The fork default and @mention together lay the foundation for the multi-agent conversation graph that the Claude Agent SDK has been building toward. The GitLab support closes the gap for teams standardized on GitLab.
For: Claude (Axion). Claude Code is the direct session runtime; these changes affect every Claude Code session and every agent spawned from it.
Verdict: build now. Fork default changes how every existing Axion agent subagent spawn behaves. Review all CLAUDE.md files that define subagent spawning to confirm inherited context is intended. Update any that expect isolated context. The @mention feature is immediately usable in multi-bridge Hermes setups.
Build #1 Claude Code Subagent Fork Default and Cross-Session Mentions: use the ai-implementation-build-intake skill to build this safely. Source: https://github.com/anthropics/claude-code/releases. Save canonical skill/agent under AXION\Skills and AXION\Agents.
Source · github.com/anthropics/claude-code/releases shows two consecutive releases in the Aug 24-26 window. Subagent fork default and @mention are explicitly in the What's changed list. GitLab token families (9 families: glrt-, gloas-, glptt-, glagent-, glimt-, glsoat-, glcbt-, glft-, glffct-) now get secret redaction. Full redaction applies to glpat- and gldt- tokens.