Ai-agent-skills brownfield-drift

Enforces architecture boundaries defined in PLAN.md. Use when a PR crosses module/service boundaries, when the dev asks "are we following the architecture?", or as a scheduled architecture health check. Not for querying what a module does — use brownfield-chat for that.

install

source · Clone the upstream repo

git clone https://github.com/wednesday-solutions/ai-agent-skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/wednesday-solutions/ai-agent-skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/brownfield-drift" ~/.claude/skills/wednesday-solutions-ai-agent-skills-brownfield-drift && rm -rf "$T"

manifest: skills/brownfield-drift/SKILL.md

source content

When to use

Dev asks "are we following the architecture?" or "is this a valid change?"
PR touches files near module boundaries or service interfaces
Weekly architecture health check
Any cross-service import was just added

When NOT to use

"What does module X do?" → use brownfield-chat
"What breaks if I change X?" → use brownfield-chat
Graph coverage is low on a file → use brownfield-fix (it fills gaps before editing)
No PLAN.md exists — drift requires machine-readable boundaries in PLAN.md

What to do

Run
```
wednesday-skills drift
```
via Bash tool
Report violations with:
- The specific edge that violates the rule
- The commit that introduced it (when available)
- The suggested fix per PLAN.md intent
For PR reviews: run
```
wednesday-skills drift --since <base-commit>
```
to only report new violations

For a single rule:

wednesday-skills drift --rule <rule-name>

Adding constraints to PLAN.md

If the project has no constraints block, add one to PLAN.md:

{
  "boundaries": [
    {
      "rule": "frontend-never-imports-db",
      "description": "Frontend components must never import DB layer directly",
      "from": "src/app/**",
      "to": "src/lib/db/**",
      "type": "forbidden"
    },
    {
      "rule": "no-circular-deps",
      "description": "No circular dependencies anywhere",
      "scope": "**",
      "type": "no-cycle"
    }
  ]
}

Violation types

Type	What it catches
`forbidden`	Import from A → B that should never exist
`ownership`	Logic pattern appearing outside its designated owner
`no-direct-import`	Direct import between services that should use API
`no-cycle`	Circular dependency between modules

Never

Auto-fix boundary violations — always ask the dev first
Flag existing violations on a PR that did not introduce them (use
```
--since
```
)
Run on projects without machine-readable PLAN.md constraints
Report the same violation twice in one review session

CLI reference

wednesday-skills drift                              # full check
wednesday-skills drift --rule frontend-never-imports-db  # single rule
wednesday-skills drift --since abc1234              # new drift only (for PR review)