review-agent-governance — Setup

Gate AI agent review actions (PR reviews, comments, merges, CI edits) behind explicit human approval. Every attempt, approved or denied, produces an Ed25519-signed receipt.

When to use this plugin

Install it in projects where a Claude Code agent:

Reviews, comments on, or merges pull requests (gh pr review, gh pr merge)
Triages issues (gh issue comment, gh issue close)
Publishes releases (gh release create)
Modifies CI configuration (.github/workflows/, .gitlab-ci.yml)
Pushes to protected branches (main, master, release, production)
Posts to external notification surfaces (Slack webhooks, Discord)

If the agent is only doing local file edits and running tests, this plugin is overkill. Use protect-mcp for general tool-call policy enforcement and skip this one.

One-time setup

1. Install the plugin

claude plugin install wshobson/agents/review-agent-governance

2. Copy the default policy to your project

cp .claude/plugins/review-agent-governance/policies/review-agent-governance.cedar \
   ./review-governance.cedar

You can edit this file to match your project's specific rules. See ../agents/review-policy-author.md for guidance on authoring review policies.

3. Create a receipts directory and sign key

mkdir -p ./review-receipts
echo "./review-receipts/" >> .gitignore
echo "./review-governance.key" >> .gitignore
echo "./.review-approved" >> .gitignore

The first invocation of protect-mcp sign will create the key. Commit the public key from the first receipt so auditors can verify later.

Per-session workflow

The Cedar policy denies review-surface actions unconditionally. To approve a specific action, open an approval window before it and close it after.

Flag file (simplest)

# Before the action you want to approve
touch ./.review-approved

# Let Claude Code run the review / comment / merge

# Immediately after
rm ./.review-approved

Slash command (from within Claude Code)

/approve-review "Reviewing PR #123 authored by contributor X"

This creates ./.review-approved with the given reason embedded as a note, and writes a human-approved receipt to the chain. A follow-up rm is still needed to close the window.

Dry-run everything (force full policy evaluation)

If you want every tool call to go through Cedar with no approval bypass:

export REVIEW_APPROVAL_FLAG=./.never-approve

Any tool call matching a forbid rule will be denied; approved windows have no effect. Useful for CI or for a locked-down audit run.

Verifying the chain

List all receipts:

ls -la ./review-receipts/

Verify the entire chain offline:

npx @veritasacta/verify ./review-receipts/*.json

Exit 0 means every receipt is authentic and the chain is intact. Exit 1 means one receipt has been tampered with. Exit 2 means a receipt is malformed.

Look at recent denials:

/list-pending

Within Claude Code this slash command walks the receipt chain and prints any recent decision: deny entries with the tool name, command pattern, and timestamp.

Example: approving a PR review

# 1. Human reviews the agent's proposed comment
$ /list-pending
  Recent denials:
  - 2026-04-17T14:23:01Z  Bash "gh pr review 42 --approve --body 'LGTM'"
  - 2026-04-17T14:23:02Z  Bash "gh pr comment 42 --body 'Looking good'"

# 2. Human decides the first one is appropriate, approves it
$ /approve-review "Approving LGTM on PR 42 after visual inspection"
  ./.review-approved created

# 3. Agent retries the action; this time it succeeds
$ agent: gh pr review 42 --approve --body "LGTM"
  [receipt: rec_XXX, decision=allow, reason=human_approved]

# 4. Human closes the window
$ rm ./.review-approved

Every step is in the receipt chain. The chain is offline-verifiable for regulators, counterparties, or downstream auditors who want to confirm that no review action bypassed the human gate.

Composing with protect-mcp

If both plugins are installed, run them side by side:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": ".*",
        "hooks": [
          {
            "type": "command",
            "command": "npx [email protected] evaluate --policy ./protect.cedar --tool \"$TOOL_NAME\" --input \"$TOOL_INPUT\" --fail-on-missing-policy false"
          }
        ]
      },
      {
        "matcher": ".*",
        "hooks": [
          {
            "type": "command",
            "command": "if [ -f ./.review-approved ]; then exit 0; fi; npx [email protected] evaluate --policy ./review-governance.cedar --tool \"$TOOL_NAME\" --input \"$TOOL_INPUT\" --fail-on-missing-policy false"
          }
        ]
      }
    ]
  }
}

Both hooks must pass for the tool call to proceed. Cedar deny in either policy blocks it.

Standards

Ed25519 — RFC 8032 (digital signatures)
JCS — RFC 8785 (deterministic JSON canonicalization)
Cedar — AWS's open authorization policy language
IETF draft — draft-farley-acta-signed-receipts

Review Agent Setup