A flexible, JSON-configurable workflow engine for Go applications. Define complex business processes using declarative JSON while maintaining full programmatic control.
Built with Cursor and MiMo Code — AI-powered development tools.
- JSON-Based Configuration — Define workflows declaratively
- Pluggable Storage — In-memory (testing) and GORM (PostgreSQL, MySQL, SQLite, MSSQL)
- Event System — Before/after transition listeners with filtering
- HTTP API — Echo framework integration with user and admin routes
- Async Dispatch — Non-blocking event channel with graceful shutdown
- Concurrent Safe — Thread-safe operations
- Versioned Migrations — Auto-upgrade schema on package update
package main
import (
"log"
"os"
"github.com/labstack/echo/v4"
"github.com/rs/zerolog"
"github.com/hamid-moghadam/go-workflow-engine/pkg/engine"
workflowecho "github.com/hamid-moghadam/go-workflow-engine/echo"
"github.com/hamid-moghadam/go-workflow-engine/pkg/store/memory"
)
func main() {
store := memory.New()
loader := engine.NewWorkflowLoader("./workflows")
loader.LoadAll()
logger := zerolog.New(os.Stdout)
service := engine.NewWorkflowService(store, engine.NewRegistry(), logger)
defer service.Close()
e := echo.New()
wc := &workflowecho.WorkflowContext{Service: service}
e.Use(workflowecho.WorkflowContextMiddleware(wc))
userGroup := e.Group("/api", workflowecho.DefaultUserIDMiddleware())
workflowecho.RegisterWorkflowRoutes(userGroup, service)
e.Start(":8080")
}go get github.com/hamid-moghadam/go-workflow-engine| Store | Package | Use Case |
|---|---|---|
| In-Memory | pkg/store/memory |
Testing, development |
| GORM | pkg/store/gorm |
Production |
For production, install a GORM driver:
go get gorm.io/driver/postgres # PostgreSQL
go get gorm.io/driver/mysql # MySQL
go get gorm.io/driver/sqlite # SQLite
go get gorm.io/driver/sqlserver # SQL ServerUse gormstore.AutoMigrate(db) instead of db.AutoMigrate() for versioned schema management.
{
"workflow_type": "approval",
"initial_step_name": "submit",
"initial_state": "Pending",
"steps": [
{
"name": "submit",
"title": "Submit Request",
"order": 1,
"actions": [
{
"name": "SUBMIT",
"next_step": "review",
"new_state": "Submitted"
}
]
},
{
"name": "review",
"title": "Review Request",
"order": 2,
"actions": [
{ "name": "APPROVE", "next_step": "done", "new_state": "Approved" },
{ "name": "REJECT", "next_step": "submit", "new_state": "Rejected" }
]
},
{
"name": "done",
"title": "Complete",
"order": 3,
"actions": []
}
]
}| Method | Endpoint | Description |
|---|---|---|
PUT |
/workflows/:type/steps/:step_name |
Execute transition |
GET |
/workflows/:type |
Get workflow instance |
GET |
/workflows/:type/steps/:step_name |
Get step details |
GET |
/admin/workflows |
List all instances |
PUT |
/admin/workflows/:id/steps/:step_name |
Admin transition |
// After transition (side effects)
service.OnAfterTransition("approval", "Approved", func(e engine.TransitionEvent) error {
emailService.Send(e.Instance.UserID, "Your request was approved")
return nil
})
// Before transition (data enrichment)
service.OnBeforeTransition("", "", func(e engine.BeforeTransitionEvent) (map[string]interface{}, error) {
e.InputData["timestamp"] = time.Now().Format(time.RFC3339)
return e.InputData, nil
})go func() {
for event := range service.EventCh() {
log.Printf("Transition: %s -> %s", event.FromState, event.ToState)
}
}()
defer service.Close()// No auth (anonymous)
userGroup := e.Group("/api", workflowecho.DefaultUserIDMiddleware())
// Custom auth (JWT, headers, API keys)
userGroup := e.Group("/api", workflowecho.UserIDMiddleware(func(c echo.Context) (int64, error) {
idStr := c.Request().Header.Get("X-User-ID")
return strconv.ParseInt(idStr, 10, 64)
}))- Full Documentation — Architecture, API reference, configuration details
- Example Application — Complete approval workflow with HTTP API
go mod download
make test
make lint
make build- Fork the repository
- Create a feature branch
- Make your changes
- Run
make ci - Open a Pull Request
MIT License — see LICENSE
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