Atomic commits with commit_checkpoint

Create CAP-gated checkpoints through MCP with dryRun, files list, and commit_close for milestones.

What you will learn

• Dry-run checkpoint
• Write SHA
• Use commit_close only after approval

Prerequisites

• Commit Authorization Protocol (CAP)
• Agent commit message schema
• Staging Engine — one Commit-Scope per commit
• Enforcement sessions

Surface

What this feature does

Prefer `commit_checkpoint` over raw git. Pipeline: enforcement_begin → staging_enforce → confidence_enforce → commit_checkpoint. `dryRun` defaults true.

How to call it

Call these MCP tools through your AGS / tower-gov host — commit_checkpoint, commit_close, commit_validate, enforcement_check.. Prefer scan/get before validate/diff, and enforce only when the change set is ready.

1. commit_validate
2. enforcement_check
3. dryRun true
4. dryRun false

{
  "message": "status/checkpoint(staging): classify auth diff\n\n…trailers…",
  "files": ["src/auth/session.ts", "src/auth/session.test.ts"],
  "dryRun": false
}

commit_close

Under CAP close-only, after explicit user approval, call commit_close with User-approved: yes and Approved-by: user. Never for ordinary checkpoints.

What success looks like

Returns new commit SHA

Message survives commit-msg hook

Enforcement trailer present

Common failure modes

CAP off

enforcement_check not ok

files span multiple Commit-Scopes

Related reference

• API surface
• Architecture