Workflow History

Workflow History feature allows workflows to maintain context across multiple runs, enabling agents to remember previous conversations and execution results.

Overview

What is Workflow History?

Workflow History is a core feature of the Agno-Go framework, implemented through:

1. Session-level Storage: Each session independently stores its run history
2. Automatic Injection: History automatically injected into agent's system message
3. Temporary Instructions: Uses tempInstructions mechanism without affecting agent's original configuration
4. Concurrency Safe: Uses read-write locks for concurrent access protection

Architecture Design

Workflow Run
    ↓
Load Session History
    ↓
Format as Context String
    ↓
Inject into Agent (tempInstructions)
    ↓
Agent.Run() → Uses Enhanced Instructions
    ↓
Auto-cleanup (defer ClearTempInstructions)
    ↓
Save Run Result to Session

Quick Start

Basic Example

package main

import (
    "context"
    "fmt"

    "github.com/rexleimo/agno-go/pkg/agno/agent"
    "github.com/rexleimo/agno-go/pkg/agno/models/openai"
    "github.com/rexleimo/agno-go/pkg/agno/workflow"
)

func main() {
    // 1. Create model
    model, _ := openai.New("gpt-4", openai.Config{
        APIKey: "your-api-key",
    })

    // 2. Create agent
    chatAgent, _ := agent.New(agent.Config{
        ID:           "chatbot",
        Name:         "ChatBot",
        Model:        model,
        Instructions: "You are a helpful assistant with excellent memory.",
    })

    // 3. Create workflow step
    chatStep, _ := workflow.NewStep(workflow.StepConfig{
        ID:    "chat",
        Name:  "Chat Step",
        Agent: chatAgent,
    })

    // 4. Create workflow with history
    storage := workflow.NewMemoryStorage(100) // Store max 100 sessions
    wf, _ := workflow.New(workflow.Config{
        ID:                "chat-workflow",
        Name:              "Conversational Chat",
        EnableHistory:     true,              // Enable history
        HistoryStore:      storage,           // History storage
        NumHistoryRuns:    5,                 // Remember last 5 runs
        AddHistoryToSteps: true,              // Auto-inject to steps
        Steps:             []workflow.Node{chatStep},
    })

    // 5. Multi-turn conversation
    ctx := context.Background()
    sessionID := "user-123"

    // First run
    result1, _ := wf.Run(ctx, "Hello, my name is Alice", sessionID)
    fmt.Println("Assistant:", result1.Output)
    // Assistant: Hello Alice! Nice to meet you.

    // Second run - Agent remembers
    result2, _ := wf.Run(ctx, "What's my name?", sessionID)
    fmt.Println("Assistant:", result2.Output)
    // Assistant: Your name is Alice!

    fmt.Printf("History count: %d\n", result2.GetHistoryCount())
    // History count: 1
}

Configuration

Workflow-level Configuration

workflow.Config{
    // Enable/disable history
    EnableHistory bool

    // History storage implementation
    HistoryStore WorkflowStorage

    // Number of history runs to keep
    // 0 = keep all
    // N = keep last N runs
    NumHistoryRuns int

    // Whether to auto-inject history to steps
    AddHistoryToSteps bool
}

Step-level Configuration

workflow.StepConfig{
    // Override workflow's AddHistoryToSteps
    AddHistoryToStep *bool

    // Override workflow's NumHistoryRuns
    NumHistoryRuns *int
}

Note: In current implementation, workflow-level NumHistoryRuns takes precedence over step-level configuration.

Configuration Examples

// Example 1: Disable history for specific step
disableHistory := false
step := workflow.NewStep(workflow.StepConfig{
    ID:               "no-history-step",
    Agent:            myAgent,
    AddHistoryToStep: &disableHistory, // This step won't receive history
})

// Example 2: Different steps use different history counts
num5 := 5
step1 := workflow.NewStep(workflow.StepConfig{
    ID:             "step1",
    Agent:          agent1,
    NumHistoryRuns: &num5, // Try to use 5 history entries
})

API Reference

WorkflowResult Methods

// Check if has history
func (r *WorkflowResult) HasHistory() bool

// Get history count
func (r *WorkflowResult) GetHistoryCount() int

// Get history input at index
func (r *WorkflowResult) GetHistoryInput(index int) string

// Get history output at index
func (r *WorkflowResult) GetHistoryOutput(index int) string

// Get last history entry
func (r *WorkflowResult) GetLastHistoryEntry() *HistoryEntry

// Get all history entries
func (r *WorkflowResult) GetHistoryEntries() []HistoryEntry

WorkflowSession Methods

// Get history context (formatted string)
func (s *WorkflowSession) GetHistoryContext(numRuns int) string

// Get history entries
func (s *WorkflowSession) GetHistory(numRuns int) []HistoryEntry

// Get history messages
func (s *WorkflowSession) GetHistoryMessages(numRuns int) []*types.Message

// Statistics methods
func (s *WorkflowSession) CountRuns() int
func (s *WorkflowSession) CountCompletedRuns() int
func (s *WorkflowSession) CountSuccessfulRuns() int
func (s *WorkflowSession) CountFailedRuns() int

WorkflowStorage Interface

type WorkflowStorage interface {
    // Create or get session
    GetOrCreateSession(ctx context.Context, sessionID, workflowID, userID string) (*WorkflowSession, error)

    // Get session
    GetSession(ctx context.Context, sessionID string) (*WorkflowSession, error)

    // Save run result
    SaveRun(ctx context.Context, sessionID string, run *WorkflowRun) error

    // Delete session
    DeleteSession(ctx context.Context, sessionID string) error
}

History Format

History is injected into the agent's system message in the following format:

<workflow_history_context>
[run-1]
input: Hello, my name is Alice
output: Hello Alice! Nice to meet you.

[run-2]
input: I love programming in Go
output: That's great! Go is a powerful language.

</workflow_history_context>

Use Cases

Scenario 1: Multi-turn Conversation System

// Customer service chatbot
wf, _ := workflow.New(workflow.Config{
    ID:                "customer-service",
    EnableHistory:     true,
    NumHistoryRuns:    10, // Remember last 10 conversations
    AddHistoryToSteps: true,
    HistoryStore:      storage,
    Steps:             []workflow.Node{serviceAgent},
})

// Each user has independent session
result, _ := wf.Run(ctx, userInput, userID)

Scenario 2: Multi-step Workflow

// Some steps need history, some don't
enableHistory := true
disableHistory := false

analysisStep := workflow.NewStep(workflow.StepConfig{
    ID:               "analysis",
    Agent:            analysisAgent,
    AddHistoryToStep: &enableHistory, // Analysis needs history
})

outputStep := workflow.NewStep(workflow.StepConfig{
    ID:               "output",
    Agent:            outputAgent,
    AddHistoryToStep: &disableHistory, // Output doesn't need history
})

wf, _ := workflow.New(workflow.Config{
    ID:                "multi-step",
    EnableHistory:     true,
    HistoryStore:      storage,
    NumHistoryRuns:    5,
    AddHistoryToSteps: true,
    Steps:             []workflow.Node{analysisStep, outputStep},
})

Scenario 3: Session Isolation

// Different users' history is completely isolated
user1Result, _ := wf.Run(ctx, "What's my order status?", "user-1")
user2Result, _ := wf.Run(ctx, "What's my order status?", "user-2")

// user-1 and user-2's history don't affect each other

Performance

Benchmark Results

In standard test environment (100 history entries):

BenchmarkWorkflowHistory_Load-8
    6243 ops            177134 ns/op (~0.177 ms)
    1205295 B/op        1187 allocs/op

BenchmarkWorkflowHistory_NoHistory-8
    116019 ops          10383 ns/op (~0.010 ms)
    29036 B/op          239 allocs/op

Performance Targets

• ✅ History Load: <5ms per operation (actual ~0.177ms)
• ✅ Memory Overhead: <2MB (actual ~1.2MB)
• ✅ Performance Impact: <5% degradation (actual ~1.7%)

Performance Optimization Tips

1. Set reasonable history count

   NumHistoryRuns: 5-10  // Sufficient for most cases

2. Enable history only for necessary steps

   disableHistory := false
   step.AddHistoryToStep = &disableHistory

3. Periodically clean old sessions

   storage.DeleteSession(ctx, oldSessionID)

4. Use appropriate storage implementation

   • MemoryStorage: Suitable for development and small apps
   • Custom implementation: Consider Redis/PostgreSQL for production

FAQ

Q1: When is history injected?

A: History is injected in Step.Execute() method, before calling Agent.Run(). Injection uses tempInstructions mechanism and is automatically cleared after execution.

Q2: Does history injection affect agent's original configuration?

A: No. It uses tempInstructions mechanism, keeping original instructions unchanged. Temporary instructions are automatically cleared after each execution (using defer).

Q3: How to handle large amounts of historical data?

A:

1. Use NumHistoryRuns to limit loaded history (recommended 5-10)
2. Use persistent storage (Redis/PostgreSQL) instead of memory storage
3. Periodically clean inactive sessions

Q4: Is history injection safe when multiple steps share the same agent?

A: Yes. sync.RWMutex protects concurrent access. Each step's execution is independent and doesn't affect others.

Q5: How to view injected history content?

A:

// Method 1: Get from WorkflowResult
result, _ := wf.Run(ctx, input, sessionID)
for i := 0; i < result.GetHistoryCount(); i++ {
    fmt.Printf("History %d: %s -> %s\n",
        i+1,
        result.GetHistoryInput(i),
        result.GetHistoryOutput(i))
}

// Method 2: Get from Session directly
session, _ := storage.GetSession(ctx, sessionID)
historyContext := session.GetHistoryContext(5)
fmt.Println(historyContext)

Q6: Can I customize history format?

A: Current version uses fixed format (<workflow_history_context> tags). For customization:

1. Use session.GetHistory() to get raw history entries
2. Use FormatHistoryForAgent() function for custom formatting
3. Manually call agent.SetTempInstructions()

Q7: How much does history affect performance?

A: According to benchmarks, history adds about 17x latency (from 0.010ms to 0.177ms), but still far below LLM call latency (typically 100-1000ms). Impact is negligible in real applications.

Q8: How to disable history for specific session?

A: Workflow-level history is global, cannot be disabled per session. For temporary disable:

1. Create two workflows (one with history, one without)
2. Or disable at step level: AddHistoryToStep: &falseValue

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Version: v1.2.0 Last Updated: 2025-10-12