Guardrail

Guardrail channels coding agents into the narrow path where they are most useful: explore with context, change files inside a sandbox, review before shipping, and preserve the few lessons worth carrying forward. It is not another agent. It is the local harness around the agents you already use.

It wraps a nono sandbox around either Charm crush or the Cursor CLI (agent), scaffolds project setup with guardrail init, stores durable agent memory in Engram under .engram/, and vendors Compound Engineering skills into .cursor/skills/ and .cursor/agents/.

The default rails are intentionally opinionated:

• agents launch through guardrail run or guardrail run -c, not plain unsandboxed sessions
• pretool policy blocks destructive git, agent commits, and edits to protected local state
• the CE loop routes work through brainstorm, plan, implementation, review, and compounding
• Engram keeps session memory while docs/solutions/ keeps curated project knowledge

Quick start

guardrail init                  # harness + CE skills/agents + doc dirs + ce-setup
guardrail init -c               # same, run ce-setup via Cursor agent
guardrail init --no-setup       # scaffold only — skip ce-setup agent
guardrail run                   # Crush — CE skills from .cursor/skills/
guardrail run -c                # Cursor CLI — CE skills + subagents
guardrail doctor                # check harness, hooks, Engram, CE, and dependencies

Then the CE loop (/ce-brainstorm → /ce-plan → /ce-work → /ce-code-review → /ce-compound). Re-run /ce-setup anytime to refresh health checks or install optional tools.

Compound Engineering

Vendored on init — no Cursor marketplace install required. Guardrail shallow-clones EveryInc/compound-engineering-plugin@main and merges:

• plugins/compound-engineering/skills/ → .cursor/skills/ce-*
• plugins/compound-engineering/agents/ → .cursor/agents/ce-*

Refresh with guardrail vendor or guardrail init -y.

Crush and Cursor both auto-load .cursor/skills/. Parallel CE subagents (multi-reviewer /ce-code-review) work best in Cursor; Crush still runs CE skills with the built-in agent tool.

The optional Cursor marketplace plugin adds IDE install UX and Cursor-native skill wiring — not required when using Guardrail.

Engram + CE

Store	Purpose
docs/solutions/	Git-tracked compounded knowledge
.engram/	Session memory + compound/* pointers (not full doc mirrors)

guardrail review -c — Engram cleanup + /ce-compound-refresh.

Upgrading

In a project:

guardrail init              # merge templates + re-sync CE
guardrail init -y           # overwrite differing bundled files + CE sync
guardrail vendor            # CE sync + optional vendors.json + PPQ refresh

In the guardrail source repo:

guardrail vendor            # git pull + CE sync + rebuild binary

See AGENTS.md for repository-specific agent guidance.