Agent Driven Development (ADD) — AI-native SDLC methodology. Coordinated agent teams: test-writers, implementers, reviewers, deployers. Spec-driven TDD, trust-but-verify orchestration, maturity lifecycle, away mode, cross-project learning. Multi-runtime (Claude Code + Codex CLI). Pure markdown + JSON on the agent side; jq required for hook scripts (see docs/runtime-dependencies.md).