Preloop

What is Preloop?

Preloop is an open-source, event-driven automation platform with built-in human-in-the-loop safety. It acts as an MCP proxy, intercepting sensitive operations called by AI agents and routing them for human approval. It integrates with issue trackers like Jira, GitHub, and GitLab.

How to use Preloop?

Clone the repository, create a Python virtual environment (3.11+), install dependencies, set up PostgreSQL 14+ with PGVector, and configure environment variables in .env. Start the API server with ./start.sh and the sync service with preloop-sync scan all. Alternatively, deploy with Docker Compose or a Helm chart for Kubernetes.

Key features of Preloop

• Event-driven automation with AI agents responding to tool events
• Human-in-the-loop safety intercepting sensitive operations for approval
• Built-in MCP server with 6 tools and JWT authentication
• Tool management and proxying of external MCP servers
• Issue tracker integration (Jira, GitHub, GitLab) with continuous sync
• Vector search and automated duplicate detection
• Compliance metrics and improvement recommendations
• Modern web UI built with Lit, Vite, and Shoelace Web Components

Use cases of Preloop

• Automate issue tracking workflows with human approval gates
• Implement compliance checks and recommendations for issue descriptions
• Detect duplicate and overlapping issues automatically
• Enable AI agents to respond to events with safety oversight
• Approve sensitive tool calls via email or mobile app notifications

FAQ from Preloop

What runtime dependencies are required?

Python 3.11+, PostgreSQL 14+ with the PGVector extension for vector search capabilities.

Can I disable self-registration?

Yes. Set REGISTRATION_ENABLED=false in your .env file or Docker environment. This hides the sign-up UI, redirects /register to /login, and returns 403 on the registration API endpoint.

How do I access the API documentation?

When the server is running, the interactive API docs are at http://localhost:8000/docs and the OpenAPI spec at http://localhost:8000/openapi.json.

What issue trackers are supported?

Jira (Cloud and Server), GitHub Issues, and GitLab Issues. Azure DevOps and Linear are planned for future releases.

What is the difference between Open Source and Enterprise Preloop?

The open-source version provides single-user approval workflows with email and mobile app notifications. The Enterprise edition adds RBAC, team-based approvals with quorum, escalation, and Slack/Mattermost notifications.