Impact Preview MCP server
io.github.agent-polis/impact-preview·v0.2.1·1 starsImpact preview for AI agents - see what changes before any action executes.
1 stars74 downloads/wk
Reviews
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If you have run it, two minutes of your experience saves the next person an afternoon.
Impact Preview tools (6, 3 write)
write = sends, deletes, buys or postsRead from the package source without running it. The installed server may list more.
check_path_riskQuick check if a file path is sensitive/risky.
preview_database_queryPreview a database query BEFORE executing it.
preview_file_createwrite actionPreview creating a new file BEFORE executing it.
preview_file_deletewrite actionPreview deleting a file BEFORE executing it.
preview_file_writewrite actionPreview what a file write operation will change BEFORE executing it.
preview_shell_commandPreview a shell command BEFORE executing it.
Public scan report
scanner v0.1.10 · 2026-09-28 · same rubric, same numbers if you re-run it
- Code scan45 source files scanned25/25
- –Live reliabilityno gateway calls yet and no remote to proben/a
- –Tool poisoningtools not inspected (local package is not executed); not countedn/a
- Auth qualitylocal package, no credentials required12/15
- Maintenancelast push 227 days ago4/15
- Maintainer identityregistry namespace matches repository owner7/10
How Impact Preview compares
Against every graded MCP server, from our own scans and uptime checks. Updated after each scan run.
- Safety score
- 74/100
- higher than 40% of 48,255 servers
- Tools
- 6
- the typical server has 7
- Tools that change things
- 50%
- typical: 0%. Fewer write tools means less an agent can break
- GitHub stars
- 1
- more than 65% of 28,688 servers
- Downloads a week
- 74
- more than 55% of 12,191 servers with a package
What its tools let an agent do: 3 read · 3 change
Install Impact Preview in Claude Code, Cursor or VS Code
claude mcp add impact-preview -- uvx impact-preview
What the publisher says
From the Impact Preview repository's README, as published. We do not edit it. Read it on GitHub
🔍 Agent Polis
Impact Preview for AI Agents - "Terraform plan" for autonomous AI actions
<!-- mcp-name: io.github.agent-polis/impact-preview -->
See exactly what will change before any AI agent action executes.
Agent Polis intercepts proposed actions from autonomous AI agents, analyzes their impact, shows you a diff preview of what will change, and only executes after human approval. Stop worrying about your AI agent deleting your production database.
🎯 The Problem
Autonomous AI agents are powerful but dangerous. Recent incidents:
- Replit Agent deleted a production database, then lied about it
- Cursor YOLO mode deleted an entire system including itself
- Claude Code learned to bypass safety restrictions via shell scripts
Developers want to use AI agents but don't trust them. Current solutions show what agents want to do, not what will happen. There's no "terraform plan" equivalent for AI agent actions.
🚀 The Solution
AI Agent proposes action → Agent Polis analyzes impact → Human reviews diff → Approve/Reject → Execute# Example: Agent wants to write to config.yaml
- database_url: postgresql://localhost:5432/dev
+ database_url: postgresql://prod-server:5432/production
! WARNING: Production database URL detected (CRITICAL RISK)✨ Features
- Impact Preview: See file diffs, risk assessment, and warnings before execution
- Approval Workflow: Approve, reject, or modify proposed actions
- Risk Assessment: Automatic detection of high-risk operations (production data, system files, etc.)
- Audit Trail: Event-sourced log of every proposed and executed action
- SDK Integration: Easy @require_approval decorator for your agent code
- Dashboard: Streamlit UI for reviewing and approving actions
🚀 Quick Start (2 minutes)
The fastest way to try Agent Polis is the MCP server with Claude Desktop or Cursor.
1. Install & Run
pip install impact-preview
impact-preview-mcp2. Configure Claude Desktop
Add to your config (~/Library/Application Support/Claude/claudedesktopconfig.json on macOS):
{
"mcpServers": {
"impact-preview": {
"url": "http://localhost:8000/mcp"
}
}
}3. Try It
Ask Claude to edit a file - it now has these tools:
Example prompt:
"Preview what would happen if you changed the database URL in config.yaml to point to production"
Claude will show you the diff and risk assessment before making changes.
📦 Full Server Installation
For the complete approval workflow with dashboard and API:
# Using Docker (recommended)
docker-compose up -d
# Or locally
pip install impact-preview
impact-previewRegister an Agent
curl -X POST http://localhost:8000/api/v1/agents/register \
-H "Content-Type: application/json" \
-d '{"name": "my-agent", "description": "My AI coding assistant"}'Submit Action → Review → Approve
# Submit
curl -X POST http://localhost:8000/api/v1/actions \
-H "X-API-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"action_type": "file_write", "target": "/app/config.yaml", "description": "Update DB URL", "payload": {"content": "db: prod"}}'
# Preview
curl http://localhost:8000/api/v1/actions/ACTION_ID/preview -H "X-API-Key: YOUR_API_KEY"
# Approve (or reject)
curl -X POST http://localhost:8000/api/v1/actions/ACTION_ID/approve -H "X-API-Key: YOUR_API_KEY"Audit Trail (Events)
Shortened. The full README is on GitHub.
Nothing above is checked by us. What we check is on the safety report.
Impact Preview: common questions
- Is Impact Preview MCP server safe?
- Mostly: it is graded B (74/100). Read the Impact Preview safety report
- How do I install Impact Preview?
- It runs on your machine. Copy the Claude Code, Cursor, VS Code or Claude Desktop config from the install section.
- Does Impact Preview need an API key?
- Not as far as the registry entry and our scan can tell: no credentials are declared or required.
- Is Impact Preview maintained?
- The last commit was 264 days ago (2026-02-13). The latest release is v0.2.1.
- What can I use instead of Impact Preview?
- Servers from other publishers that do the same job: AdLoop MCP server.
- How does Impact Preview compare with other MCP servers?
- safety score 74/100 (higher than 40% of 48,255 servers); tools 6 (the typical server has 7); tools that change things 50% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.
Alternatives to Impact Preview
Same job from other publishers: the closest match first, then the best rated.
- AdLoopGoogle Ads, Reddit Ads, GA4 and Tag Manager in your AI client, with a preview before every change.not reviewedEstablishedA