Workflow

An easy-to-use workflow automation library for Go. Supports conditional branching, parallel execution, embedded scripting, and execution checkpointing.

Think of it like a lightweight hybrid of Temporal and AWS Step Functions.

When defining steps, you have access to string templating and scripting features using the Risor language.

Main Concepts

Concept	Description
Workflow	A repeatable process defined as a directed graph of steps
Steps	Individual nodes in the workflow graph
Activities	Functions that perform the actual work
Edges	Define flow between steps
Execution	A single run of a workflow
State	Shared mutable state that persists for the duration of an execution

How They Work Together

Workflows define Steps that execute Activities. An Execution is a single run of a workflow. When a step finishes, its outgoing Edges are evaluated and the next step(s) are selected based on any associated conditions. The State may be read and written to by the activities.

Quick Example

package main

import (
	"context"
	"fmt"
	"log"

	"github.com/deepnoodle-ai/workflow"
	"github.com/deepnoodle-ai/workflow/activities"
)

func main() {

	attempt := 0

	myOperation := func(ctx workflow.Context, input map[string]any) (string, error) {
		attempt++
		if attempt < 3 { // Simulated failure
			return "", fmt.Errorf("service is temporarily unavailable")
		}
		return "SUCCESS", nil
	}

	w, err := workflow.New(workflow.Options{
		Name: "demo",
		Steps: []*workflow.Step{
			{
				Name:     "Call My Operation",
				Activity: "my_operation",
				Store:    "result",
				Retry:    []*workflow.RetryConfig{{MaxRetries: 2}},
				Next:     []*workflow.Edge{{Step: "Finish"}},
			},
			{
				Name:     "Finish",
				Activity: "print",
				Parameters: map[string]any{
					"message": "🎉 Workflow completed successfully! Result: ${state.result}",
				},
			},
		},
	})
	if err != nil {
		log.Fatal(err)
	}

	execution, err := workflow.NewExecution(workflow.ExecutionOptions{
		Workflow: w,
		Logger:   workflow.NewLogger(),
		Activities: []workflow.Activity{
			workflow.NewTypedActivityFunction("my_operation", myOperation),
			activities.NewPrintActivity(),
		},
	})
	if err != nil {
		log.Fatal(err)
	}

	if err := execution.Run(context.Background()); err != nil {
		log.Fatal(err)
	}
}