Architecture

Design decisions that matter

Cerberus is built on a core philosophy: deterministic core, AI-assisted reasoning at the edges.

Three-Tier Classification Pipeline

Named after the three-headed dog that guards the underworld. Three tiers, each progressively more expensive, each resolving failures the cheaper tiers couldn't.

📄
Test Suite Output
JUnit XML / Playwright JSON
📥
cerberus ingest
Parse & store results
🗄️
SQLite Database
Historical run data
Three-Tier Classification Pipeline
📏
Rules
Deterministic, <1ms
💾
Cache
Signature lookup, <5ms
🤖
AI
Claude / OpenAI-compatible
~40% resolved~30% resolved~30% resolved
🚦
cerberus gate
Deterministic, 0/1 exit code
💬
PR Comment
Plain-English report
📌
Annotations
::error / ::warning
🔒
Exit Code
0 = pass, 1 = fail
1

Rule-Based Pre-filter

Cost: zero • Latency: <1ms • Resolves: ~40%

  • Retry pass → flaky (0.9)
  • 3+ consecutive fails → regression
  • Navigation timeout → flaky (0.8)
2

Verdict Cache

Cost: zero • Latency: <5ms • Resolves: ~30%

  • SHA-256 error signature
  • 30-day TTL
  • Same shape = same verdict
3

AI Classification

Cost: 1 API call • Latency: 1-5s • Resolves: ~30%

  • Only for new error shapes
  • System prompt with signals
  • Validated JSON output