AI Agent System Architecture
A single VPS turns GitLab issue events into reviewed code changes, with each system boundary visible below. Select any node for its technical implementation details.
webhookwebhookcreates / updatesplanning + reviewcode changestraces
GitLab
Agent Orchestrator — single VPS
Technologies
Orchestration & Backend
- Python 3.10
- The pipeline's implementation language
- LangGraph
- Stateful graph orchestration, checkpointed to SQLite
- FastAPI + Uvicorn
- The webhook API
- Pydantic
- The shared state object every agent reads and writes
- uv
- Python dependency management
AI & Code Generation
- OpenAI API (GPT-5.6 family)
- Planner and Reviewer, independently configurable per role
- OpenCode CLI
- The only agent allowed to modify code, run as an isolated subprocess
Quality & Observability
- pytest
- The orchestrator's own test suite
- gitleaks
- Secret scanning, a critical review gate
- semgrep
- Static analysis, a critical review gate
- Langfuse Cloud
- Full trace per run: nodes, individual LLM calls, tokens, cost
Infrastructure
- GitLab
- Issues, merge requests, CI, the entire control surface
- systemd
- Process supervision, no containers
- Caddy
- Reverse proxy with automatic HTTPS
- SQLite
- Local checkpoint persistence, no external database