October 4, 2025 by Mishael Ochu

Hydra Agents: Building an AI-Powered PR Review System

Automating Code Review with Claude AI and Jenkins

When managing multiple client repositories with frequent pull requests, manual code review becomes a bottleneck. I built Hydra Agents to solve this - an event-driven system that uses Claude AI to automatically review pull requests against Jira requirements, security standards, and code quality guidelines.

The Architecture

The system is built on a cost-optimized, event-driven design:

1. Bitbucket Webhooks trigger reviews when PRs are created or updated
2. Jenkins Pipelines orchestrate the review process
3. Claude AI analyzes code changes against Jira ticket requirements
4. Discord Bot provides optional human-in-the-loop approval before publishing

This architecture means no idle resources - the system only runs when there’s work to do, eliminating the cost of persistent agent containers.

Key Features

• Context-Aware Reviews: Claude analyzes PRs against the actual Jira requirements, not just blind code review
• Multi-Repository Support: Handles large monorepos with 20+ repositories using intelligent caching
• Comprehensive Analysis: Reviews cover security vulnerabilities, code quality, test coverage, and performance implications
• Automated Build/Test: Detects build systems (npm, maven, gradle, pip, composer) and runs CI automatically

Repository Caching Strategy

For clients with many repositories, clone times can be significant. The system maintains a persistent cache that reduces review time from 2-5 minutes on first review to 30-60 seconds for subsequent reviews.

// Cache structure for multi-repo clients
/var/jenkins/client-repos/
  └── client-name/
      └── pr-review/
          ├── shipping-api/
          ├── integrations/
          └── legacy-system/
              ├── admin-back-office/
              ├── franchise/
              └── ... (20+ repos)

Human-in-the-Loop with Discord

Not every automated review should be published immediately. The Discord bot provides an approval workflow with rich embeds showing the review summary, allowing team leads to approve or reject before the review is posted to Bitbucket.

Results

The system currently handles PR reviews for multiple clients, providing consistent, thorough reviews within minutes of PR creation. The event-driven architecture keeps costs minimal while the Claude AI integration ensures reviews are genuinely useful - not just automated noise.

Building automation that augments human capability rather than replacing it entirely has been the key to adoption and trust.