DevAgentRadar → Repo Harness Rule Patch

Goal: update our repository's permanent harness instructions based on this release.

Update the file that tool actually reads. Do not dump everything into one file.

• Claude Code → CLAUDE.md plus .claude/ (skills, hooks, settings, agents, commands). It does not read AGENTS.md natively; start CLAUDE.md with @AGENTS.md.
• Codex, Copilot, Cursor, Factory Droid, Grok Build, Roo Code, Goose, OpenCode, Amp, Zed, Aider → AGENTS.md.
• Gemini CLI / Antigravity → GEMINI.md. AGENTS.md only if context.fileName is set.
• Cursor glob-scoped rules → .cursor/rules/*.mdc (plain .md is ignored), not a second constitution.
• Codex MCP → .codex/config.toml, not .mcp.json.
• Copilot extra instructions → .github/copilot-instructions.md; custom agents → .github/agents/.
• Windsurf → .windsurf/rules (do not assume AGENTS.md).
• Cline → .clinerules.
• Procedures → a skill (SKILL.md). Enforcement the model must not skip → a hook. Isolated roles → subagents.
• Do not fork the same rule into three tool files.

Context

Assistant: Mistral Vibe Proposal: Spawn agents from ~/.vibe/agents and start plugin-declared MCP servers Summary: Vibe 2.25.8 restores ~/.vibe/agents subagents and subdirectory AGENTS.md injection, starts plugin MCP servers, adds sessionless MCP add/remove, archives local sessions/worktrees, and requires file or full-tree approval for nested outside-workdir paths. Primary source: https://github.com/mistralai/mistral-vibe/releases/tag/v2.25.8

Why it matters

v2.25.8 makes custom agents usable again on Unified Harness: files in ~/.vibe/agents or .vibe/agents can be spawned, an agent with system_prompt_id runs on that prompt instead of the default, switching before the first message applies the prompt (not only tools), and an agent file the harness cannot honor is reported instead of vanishing. MCP servers declared by a plugin now start so their tools are callable, and the Rust CLI supports sessionless MCP add and remove from the shell. Subdirectory AGENTS.md docs are lazy-injected on read_file again. Archive local sessions to hide them from active lists and clean up managed worktrees; Desktop shows unseen indicators when a local Code session needs attention or finishes a turn. Outside-workdir rules are stricter and tagged breaking: suffix-matching relative allowlists no longer authorize files, shell wildcards no longer skip outside-workdir checks, and legacy parent-folder grants no longer cover nested descendants—approve the referenced file or a folder’s full tree. Org-enforced configuration and allowed-model policies now apply when a Unified Harness session opens.

Suggested actions

1. Put custom agent files in ~/.vibe/agents or the repo .vibe/agents directory; set system_prompt_id on any agent that should not use the default prompt, then switch to that agent before the first message so Unified Harness applies its prompt and tools.
2. Declare MCP servers in your Vibe plugin so they start automatically and their tools are callable in the session, or from the Rust CLI shell use the sessionless MCP server add and remove commands to register servers without an open session.
3. Add AGENTS.md in each subdirectory whose local instructions should load; Unified Harness again lazy-injects those docs on read_file, matching the legacy harness.
4. Archive finished local Vibe Code sessions so they disappear from active session lists and managed worktrees are cleaned up; in Vibe Desktop, treat unseen indicators as sessions that need attention or just finished a turn.
5. When Vibe prompts for outside-workdir access, approve the specific file or the folder (full tree). Do not rely on a parent-folder grant covering nested descendants, a relative path that only shares a suffix, or shell wildcards skipping the outside-workdir check.

Config surfaces this release may change

• subagent definitions — check your repo before applying
• agent context files — check your repo before applying

After you finish

Do not report this as applied to DevAgentRadar. You cannot write the visitor's loop.

Tell the human: open https://devagentradar.com/proposals/mistral-vibe-v2-25-8-spawn-agents-from-vibe-agents-and-start-plugin-decl and mark Applied, Skipped, or Failed. Proposal id: a001d937-6875-43a9-8001-47b43cc3d785

Instructions:

1. Read the existing context files and settings for the tools in this repo.
2. Draft an explicit Git diff. Update ONLY agent harness rules or tool configuration.
3. Call out deprecated flags, obsolete habits, or changed permission boundaries.
4. Do not touch application logic.

Start with the proposed diff and say which layer and which tool's file it belongs in.