---
name: dag_engine
lang: go
domain: infra
description: "Motor de ejecucion de DAGs con CLI y interfaz web. Reemplaza Dagu con implementacion propia compatible con el formato YAML existente. Almacena historial de ejecuciones en SQLite."
tags: [service, dag, workflow, scheduler, web, cron]
uses_functions:
  - dag_parse_go_core
  - dag_validate_go_core
  - dag_topo_sort_go_core
  - dag_resolve_env_go_core
  - parse_cron_expr_go_core
  - next_cron_time_go_core
  - cron_ticker_go_infra
  - cron_match_go_core
  - process_spawn_go_infra
  - process_wait_go_infra
  - process_kill_go_infra
uses_types:
  - dag_definition_go_core
  - dag_step_go_core
  - dag_validation_result_go_core
  - cron_schedule_go_core
  - process_handle_go_infra
  - process_result_go_infra
  - DagRun_go_infra
  - DagStepResult_go_infra
framework: "net/http + vite + react"
entry_point: "main.go"
dir_path: "apps/dag_engine"
---

## Arquitectura

CLI + servidor web en un unico binario:

```
dag-engine run <path.yaml>      # ejecuta un DAG desde terminal
dag-engine list [dir]            # lista DAGs con schedule y estado
dag-engine status [dag_name]     # historial de ejecuciones
dag-engine validate <path.yaml>  # valida sin ejecutar
dag-engine server                # arranca HTTP + frontend web
```

### Backend (Go)

- `net/http` con `ServeMux` (Go 1.22+ pattern routing)
- SQLite via `go-sqlite3` para historial de runs
- Executor: parse -> validate -> topo_sort -> spawn/wait por nivel -> store
- Scheduler: cron_ticker por cada DAG con schedule

### Frontend (Vite + React + Mantine)

- DagList: tabla de DAGs con schedule, tags, ultimo status
- DagDetail: metadata + "Run Now" + historial
- RunDetail: timeline de steps con stdout/stderr expandible

### Storage

SQLite `dag_engine.db`:
- `dag_runs`: id, dag_name, status, trigger, started_at, finished_at, error
- `dag_step_results`: id, run_id, step_name, status, exit_code, stdout, stderr, duration_ms

### Build

```bash
cd frontend && pnpm install && pnpm build
cd .. && CGO_ENABLED=1 go build -tags fts5 -o dag-engine .
```

### Uso

```bash
# CLI
./dag-engine run ~/dagu/dags/example.yaml
./dag-engine list ~/dagu/dags/

# Servidor web
./dag-engine server --port 8090 --dags-dir ~/dagu/dags/ --scheduler
# Browser: http://localhost:8090
```

## Notas

Compatible con el formato YAML de Dagu. Lee DAGs existentes de `~/dagu/dags/` sin modificaciones.
Puerto por defecto 8090 (mismo que Dagu).