Vega

Fault-tolerant AI agent orchestration for Go.

Vega makes it easy to build reliable AI agent systems with Erlang-style supervision. Use the YAML DSL for rapid prototyping or the Go library for full control.

Chat

The fastest way to use Vega is the built-in chat interface. Responses stream token-by-token, and tool calls appear inline as collapsible panels with arguments, results, and execution time.

vega serve team.vega.yaml
# Open http://localhost:3001 → pick an agent → start chatting

No YAML file? vega serve starts with a default assistant.

Streaming API

Chat is also available as an SSE endpoint for programmatic use:

curl -N -X POST localhost:3001/api/agents/assistant/chat/stream \
  -H 'Content-Type: application/json' \
  -d '{"message": "Search for recent Go releases"}'

event: text_delta
data: {"type":"text_delta","delta":"Let me "}

event: tool_start
data: {"type":"tool_start","tool_call_id":"tc_1","tool_name":"web_search","arguments":{"query":"Go releases 2026"}}

event: tool_end
data: {"type":"tool_end","tool_call_id":"tc_1","tool_name":"web_search","result":"Found 3 results...","duration_ms":1250}

event: text_delta
data: {"type":"text_delta","delta":"Based on the results..."}

event: done
data: {"type":"done"}

Event	Fields	Description
text_delta	delta	Incremental text content
tool_start	tool_call_id, tool_name, arguments	Tool execution began
tool_end	tool_call_id, tool_name, result, duration_ms	Tool execution finished
error	error	An error occurred
done		Stream complete

A blocking (non-streaming) endpoint is also available at POST /api/agents/{name}/chat.

Go Library

stream, _ := proc.SendStreamRich(ctx, "Search for recent Go releases")
for event := range stream.Events() {
    switch event.Type {
    case vega.ChatEventTextDelta:
        fmt.Print(event.Delta)
    case vega.ChatEventToolStart:
        fmt.Printf("\n[calling %s]\n", event.ToolName)
    case vega.ChatEventToolEnd:
        fmt.Printf("[done in %dms]\n", event.DurationMs)
    }
}

Use SendStream for simple text-only streaming, or Send for a blocking call.

---

Installation

CLI Tool

# Homebrew (macOS / Linux)
brew install everydev1618/tap/vega

# Go install
go install github.com/everydev1618/govega/cmd/vega@latest

# Or download a binary from GitHub Releases
# https://github.com/everydev1618/govega/releases

Go Library

go get github.com/everydev1618/govega

Configuration

Set your Anthropic API key:

export ANTHROPIC_API_KEY=your-key-here

---

Quick Start

Option 1: Go Library

package main

import (
    "context"
    "fmt"
    "log"

    "github.com/everydev1618/govega"
    "github.com/everydev1618/govega/llm"
)

func main() {
    // Create LLM backend
    anthropic := llm.NewAnthropic()

    // Create orchestrator
    orch := vega.NewOrchestrator(vega.WithLLM(anthropic))

    // Define an agent
    agent := vega.Agent{
        Name:   "assistant",
        Model:  "claude-sonnet-4-20250514",
        System: vega.StaticPrompt("You are a helpful coding assistant."),
    }

    // Spawn a process
    proc, err := orch.Spawn(agent)
    if err != nil {
        log.Fatal(err)
    }

    // Send a message
    ctx := context.Background()
    response, err := proc.Send(ctx, "Write a hello world function in Go")
    if err != nil {
        proc.Fail(err)  // Mark process as failed
        log.Fatal(err)
    }

    // IMPORTANT: Always mark processes as completed when done
    proc.Complete(response)

    fmt.Println(response)

    // Cleanup
    orch.Shutdown(ctx)
}

Option 2: YAML DSL

Create assistant.vega.yaml:

name: Assistant

agents:
  helper:
    model: claude-sonnet-4-20250514
    system: You are a helpful assistant.

Run interactively:

vega repl assistant.vega.yaml
> /ask helper
> What is the capital of France?

---

⚠️ Important: Process Lifecycle

Every spawned process must be completed or failed. This is the most common mistake when using Vega.

// ❌ WRONG - process leaks, stays "running" forever
proc, _ := orch.Spawn(agent)
proc.SendAsync(task)
return "Started!"

// ✅ CORRECT - process properly completed
proc, _ := orch.Spawn(agent)
response, err := proc.Send(ctx, task)
if err != nil {
    proc.Fail(err)
    return err
}
proc.Complete(response)

See Best Practices for more details.

---

Architecture

flowchart TB
    subgraph Orchestrator["Orchestrator"]
        direction TB
        Registry["Agent Registry"]
        ProcessMgr["Process Manager"]
        Groups["Process Groups"]
        RateLimiter["Rate Limiter"]
    end

    subgraph Supervision["Supervision Tree"]
        direction TB
        Supervisor["Supervisor"]
        Strategy{{"Strategy<br/>OneForOne | OneForAll | RestForOne"}}
        Supervisor --> Strategy
    end

    subgraph Processes["Processes"]
        direction LR
        P1["Process 1"]
        P2["Process 2"]
        P3["Process 3"]
    end

    subgraph Agent["Agent (Blueprint)"]
        Model["Model"]
        System["System Prompt"]
        Tools["Tools"]
        Config["Retry / Circuit Breaker / Budget"]
    end

    subgraph LLMLoop["LLM Execution Loop"]
        direction TB
        Build["Build Messages"]
        Call["LLM Call"]
        Parse["Parse Response"]
        ToolExec["Execute Tools"]
        Build --> Call --> Parse
        Parse -->|"Tool Use"| ToolExec --> Build
        Parse -->|"Text Response"| Done["Complete"]
    end

    Agent -->|"spawn"| Orchestrator
    Orchestrator -->|"creates"| Processes
    Supervisor -->|"monitors"| Processes
    Processes -->|"run"| LLMLoop

    P1 <-->|"links"| P2
    P2 -.->|"monitors"| P3

Loading

flowchart LR
    subgraph Lifecycle["Process Lifecycle"]
        Pending["🟡 Pending"]
        Running["🟢 Running"]
        Completed["✅ Completed"]
        Failed["❌ Failed"]
        Timeout["⏱️ Timeout"]

        Pending --> Running
        Running --> Completed
        Running --> Failed
        Running --> Timeout
        Failed -->|"restart"| Pending
    end

Loading

flowchart TB
    subgraph SpawnTree["Spawn Tree"]
        Root["Orchestrator Process"]
        Child1["Worker 1<br/>depth: 1"]
        Child2["Worker 2<br/>depth: 1"]
        GrandChild["Sub-worker<br/>depth: 2"]

        Root --> Child1
        Root --> Child2
        Child1 --> GrandChild
    end

Loading

---

Features

Erlang-Style Supervision

Processes automatically restart on failure with configurable strategies:

proc, err := orch.Spawn(agent, vega.WithSupervision(vega.Supervision{
    Strategy:    vega.Restart,  // Restart, Stop, or Escalate
    MaxRestarts: 3,
    Window:      5 * time.Minute,
    Backoff: vega.BackoffConfig{
        Initial:    100 * time.Millisecond,
        Multiplier: 2.0,
        Max:        30 * time.Second,
    },
}))

Or in YAML:

agents:
  worker:
    model: claude-sonnet-4-20250514
    system: You process tasks reliably.
    supervision:
      strategy: restart
      max_restarts: 3
      window: 5m

Tools

Register tools for agents to use:

tools := vega.NewTools()
tools.RegisterBuiltins() // read_file, write_file, run_command

// Register custom tool
tools.Register("greet", func(name string) string {
    return "Hello, " + name + "!"
})

agent := vega.Agent{
    Name:  "greeter",
    Tools: tools,
}

Or define in YAML with full HTTP support:

tools:
  fetch_weather:
    description: Get weather for a city
    params:
      - name: city
        type: string
        required: true
    implementation:
      type: http
      method: GET
      url: "https://api.weather.com/v1/current?city={{.city}}"
      headers:
        Authorization: "Bearer {{.api_key}}"
      timeout: 10s

  create_issue:
    description: Create a GitHub issue
    params:
      - name: title
        type: string
        required: true
      - name: body
        type: string
        required: true
    implementation:
      type: http
      method: POST
      url: "https://api.github.com/repos/{{.owner}}/{{.repo}}/issues"
      headers:
        Authorization: "token {{.token}}"
        Content-Type: application/json
      body:
        title: "{{.title}}"
        body: "{{.body}}"
      timeout: 30s

  run_script:
    description: Execute a shell script
    params:
      - name: script
        type: string
        required: true
    implementation:
      type: exec
      command: "bash -c '{{.script}}'"
      timeout: 60s

Tool implementations support {{.param}} template interpolation for dynamic values.

Streaming Responses

See the Chat section at the top for SendStreamRich (structured events with tool visibility).

For simple text-only streaming:

stream, err := proc.SendStream(ctx, "Tell me a story")
if err != nil {
    log.Fatal(err)
}

for chunk := range stream.Chunks() {
    fmt.Print(chunk)
}
fmt.Println()

Async Operations

// Fire and forget
future := proc.SendAsync("Process this in background")

// Do other work...

// Wait for result
response, err := future.Await(ctx)

Parallel Execution (DSL)

steps:
  - parallel:
      - agent1:
          send: "Task 1"
          save: result1
      - agent2:
          send: "Task 2"
          save: result2
  - combiner:
      send: "Combine: {{result1}} and {{result2}}"

Rate Limiting & Circuit Breakers

orch := vega.NewOrchestrator(
    vega.WithLLM(anthropic),
    vega.WithRateLimits(map[string]vega.RateLimitConfig{
        "claude-sonnet-4-20250514": {
            RequestsPerMinute: 60,
            TokensPerMinute:   100000,
        },
    }),
)

agent := vega.Agent{
    CircuitBreaker: &vega.CircuitBreaker{
        Threshold:  5,           // Open after 5 failures
        ResetAfter: time.Minute, // Try again after 1 minute
    },
}

Intelligent Retry with Error Classification

Vega automatically classifies errors and retries appropriately:

agent := vega.Agent{
    Name: "resilient-worker",
    Retry: &vega.RetryPolicy{
        MaxAttempts: 5,
        Backoff: vega.BackoffConfig{
            Initial:    100 * time.Millisecond,
            Multiplier: 2.0,
            Max:        30 * time.Second,
            Jitter:     0.1, // ±10% randomness
            Type:       vega.BackoffExponential,
        },
        RetryOn: []vega.ErrorClass{
            vega.ErrClassRateLimit,
            vega.ErrClassOverloaded,
            vega.ErrClassTimeout,
            vega.ErrClassTemporary,
        },
    },
}

Error classes are automatically detected:

• ErrClassRateLimit - 429 errors, "rate limit" messages
• ErrClassOverloaded - 503 errors, capacity issues
• ErrClassTimeout - Deadline exceeded, connection timeouts
• ErrClassTemporary - Transient server errors (5xx)
• ErrClassAuthentication - 401/403 errors (not retried)
• ErrClassInvalidRequest - 400 errors (not retried)
• ErrClassBudgetExceeded - Cost limits (not retried)

Configurable Iteration Limits

Control how many tool call loops an agent can perform:

agent := vega.Agent{
    Name:          "deep-researcher",
    MaxIterations: 100, // Default is 50
}

Conversation History

Vega provides flexible ways to manage conversation context across sessions.

Resume Conversations with WithMessages

Spawn a process with pre-existing conversation history:

// Load previous conversation (from database, file, etc.)
history := []vega.Message{
    {Role: vega.RoleUser, Content: "What's our project deadline?"},
    {Role: vega.RoleAssistant, Content: "The deadline is March 15th."},
}

// Spawn with existing history - the agent remembers the conversation
proc, err := orch.Spawn(agent, vega.WithMessages(history))
if err != nil {
    log.Fatal(err)
}

// Continue the conversation naturally
response, _ := proc.Send(ctx, "Can we extend it by a week?")
// Agent knows "it" refers to the March 15th deadline

Serialize Messages for Persistence

Save and restore conversations using JSON:

// Save conversation to database/file
messages := []vega.Message{
    {Role: vega.RoleUser, Content: "Hello"},
    {Role: vega.RoleAssistant, Content: "Hi there!"},
}
data, err := vega.MarshalMessages(messages)
// Store `data` in your database

// Later, restore the conversation
restored, err := vega.UnmarshalMessages(data)
proc, err := orch.Spawn(agent, vega.WithMessages(restored))

Token-Aware Context with TokenBudgetContext

Automatically manage context within a token budget:

// Create context with 8000 token budget (~32k chars)
ctx := vega.NewTokenBudgetContext(8000)

// Optionally load existing history
ctx.Load(previousMessages)

agent := vega.Agent{
    Name:    "assistant",
    Context: ctx, // Attach to agent
}

// As conversation grows, oldest messages are automatically trimmed
// to stay within the 8000 token budget

// Save for later
snapshot := ctx.Snapshot()
data, _ := vega.MarshalMessages(snapshot)

TokenBudgetContext features:

• Automatic trimming of oldest messages when budget exceeded
• Token estimation (~4 chars per token)
• Load() to restore from persistence
• Snapshot() to get messages for saving
• Thread-safe for concurrent use

Context Auto-Compaction

For smarter context management with LLM-powered summarization:

// Create a sliding window context that keeps recent messages
// and summarizes older ones
ctx := vega.NewSlidingWindowContext(20) // Keep last 20 messages

agent := vega.Agent{
    Name:    "long-conversation-agent",
    Context: ctx,
}

// Check if compaction is needed
if ctx.NeedsCompaction(50000) { // 50k token threshold
    err := ctx.Compact(llm) // Uses LLM to summarize old messages
}

The SlidingWindowContext automatically:

• Keeps a configurable number of recent messages
• Can summarize older messages using the LLM
• Preserves important context while reducing token usage

When to use which:

Context Manager	Best For
WithMessages only	Simple resume, short conversations
TokenBudgetContext	Long conversations, automatic trimming, persistence
SlidingWindowContext	Very long conversations needing intelligent summarization

Budget Control

agent := vega.Agent{
    Budget: &vega.Budget{
        Limit:    5.0,           // $5.00 max
        OnExceed: vega.BudgetBlock,
    },
}

Spawn Tree Tracking

Track parent-child relationships when agents spawn other agents:

// When spawning from a parent process, use WithParent to establish the relationship
childProc, err := orch.Spawn(childAgent,
    vega.WithParent(parentProc),           // Track parent-child relationship
    vega.WithSpawnReason("Process data"),  // Optional context for the spawn
)

// The child process will have:
// - ParentID: parent's process ID
// - ParentAgent: parent's agent name
// - SpawnDepth: parent's depth + 1

// Query the entire spawn tree
tree := orch.GetSpawnTree()
// Returns []*SpawnTreeNode with hierarchical structure

For tools that spawn processes, the parent process is automatically available via context:

func mySpawnTool(ctx context.Context, params map[string]any) (string, error) {
    // Get the calling process from context
    parent := vega.ProcessFromContext(ctx)

    // Spawn with parent tracking
    child, err := orch.Spawn(agent,
        vega.WithParent(parent),
        vega.WithSpawnReason(params["task"].(string)),
    )
    // ...
}

The spawn tree structure:

type SpawnTreeNode struct {
    ProcessID   string           `json:"process_id"`
    AgentName   string           `json:"agent_name"`
    Task        string           `json:"task"`
    Status      Status           `json:"status"`
    SpawnDepth  int              `json:"spawn_depth"`
    SpawnReason string           `json:"spawn_reason,omitempty"`
    StartedAt   time.Time        `json:"started_at"`
    Children    []*SpawnTreeNode `json:"children,omitempty"`
}

MCP (Model Context Protocol) Servers

Connect to MCP servers to use external tools:

import "github.com/everydev1618/govega/mcp"

tools := vega.NewTools(
    vega.WithMCPServer(mcp.ServerConfig{
        Name:    "filesystem",
        Command: "npx",
        Args:    []string{"-y", "@modelcontextprotocol/server-filesystem", "/workspace"},
    }),
    vega.WithMCPServer(mcp.ServerConfig{
        Name:    "github",
        Command: "npx",
        Args:    []string{"-y", "@modelcontextprotocol/server-github"},
        Env:     map[string]string{"GITHUB_TOKEN": os.Getenv("GITHUB_TOKEN")},
    }),
)

// Connect to all MCP servers
ctx := context.Background()
if err := tools.ConnectMCP(ctx); err != nil {
    log.Fatal(err)
}
defer tools.DisconnectMCP()

// Tools are automatically registered with prefix: servername__toolname
// e.g., "filesystem__read_file", "github__create_issue"

Or in YAML:

settings:
  mcp:
    servers:
      - name: filesystem
        transport: stdio
        command: npx
        args: ["-y", "@modelcontextprotocol/server-filesystem", "/workspace"]
      - name: github
        command: npx
        args: ["-y", "@modelcontextprotocol/server-github"]
        env:
          GITHUB_TOKEN: "${GITHUB_TOKEN}"
        timeout: 30s

agents:
  coder:
    model: claude-sonnet-4-20250514
    system: You are a coding assistant.
    tools:
      - filesystem__*   # All tools from filesystem server
      - github__create_issue

Web Dashboard & REST API

Monitor and control your agents through a browser-based dashboard:

vega serve team.vega.yaml
# Open http://localhost:3001

The dashboard provides:

• Chat — Real-time streaming chat with inline tool call panels (see top of README)
• Overview — Live stats, recent events, active processes
• Process Explorer — Sortable process list with conversation history
• Spawn Tree — Hierarchical view of parent-child process relationships
• Event Stream — Real-time SSE feed with filtering
• Agent Registry — Agent definitions from your .vega.yaml
• MCP Servers — Connection status and available tools
• Workflow Launcher — Run workflows from the browser with auto-generated input forms
• Cost Dashboard — Per-agent and per-process cost tracking

REST API — All data is also available via JSON endpoints:

curl localhost:3001/api/processes    # List processes
curl localhost:3001/api/agents       # List agents
curl localhost:3001/api/stats        # Aggregate metrics
curl localhost:3001/api/spawn-tree   # Spawn tree
curl localhost:3001/api/workflows    # List workflows
curl localhost:3001/api/mcp/servers  # MCP server status
curl localhost:3001/api/events       # SSE event stream

# Launch a workflow
curl -X POST localhost:3001/api/workflows/review/run \
  -H 'Content-Type: application/json' \
  -d '{"task": "Write a sort function"}'

# Chat (see Streaming API section at top of README)
curl -X POST localhost:3001/api/agents/assistant/chat \
  -H 'Content-Type: application/json' \
  -d '{"message": "Hello!"}'

Flags:

• --addr :3001 — HTTP listen address (default :3001)
• --db .vega-serve.db — SQLite database path for persistent history

Historical process data, events, and workflow runs persist across restarts via SQLite.

Built-in Meta-Agents

vega serve injects two meta-agents automatically — no YAML required.

Mother

Mother is the agent architect. Talk to her to create, update, or delete agents through conversation. She knows all available tools, skills, and MCP servers, and designs teams rather than solo agents.

You: I need an agent that researches competitors
Mother: I'll create a researcher with web tools and a lead agent to synthesize...

Mother is always available in the sidebar or via POST /api/agents/mother/chat.

Hermes

Hermes is the cosmic orchestrator — a boy traveling the Vega universe with unlimited reach. Give him any goal and he figures out which agents to involve, routes work across the whole population, calls on Mother when new agents are needed, and synthesizes everything into a result.

You → Hermes: "Do a competitive analysis of our top 3 competitors and write it up"

Hermes → list_agents           (surveys who's available)
Hermes → send_to_agent(mother, "create a web researcher agent")
Hermes → send_to_agent(researcher, "research competitor A...")
Hermes → send_to_agent(researcher, "research competitor B...")
Hermes → send_to_agent(writer,     "write up the analysis...")
Hermes → You: polished result

Hermes has two tools:

• list_agents — see all agents with their purpose summaries
• send_to_agent — route a task to any agent by name, including Mother

The mythological fit is intentional: Hermes's mother in Greek mythology was Maia.

Telegram

Chat with your Vega agents from Telegram — no public URL or port forwarding needed. The bot uses long polling.

Setup:

1. Create a bot via @BotFather and copy the token
2. Add to ~/.vega/env:

TELEGRAM_BOT_TOKEN=your-token-here
# Optional: override which agent handles messages (defaults to hermes)
# TELEGRAM_AGENT=assistant

3. Run vega serve — you'll see telegram bot started agent=hermes in the logs
4. Open Telegram, find your bot, and start chatting

By default every message goes to Hermes, so you can describe any goal and he'll route it across your full agent population. Each Telegram user gets their own isolated agent clone — conversation history is stored per-user and accessible via the REST API:

curl localhost:3001/api/agents/hermes:<telegram-user-id>/chat

The env file at ~/.vega/env is loaded automatically on startup — no shell export needed.

Agent Skills

Skills provide dynamic prompt injection based on message context:

import "github.com/everydev1618/govega/skills"

// Load skills from directories
loader := skills.NewLoader("./skills", "~/.vega/skills")
loader.Load(ctx)

// Wrap system prompt with skills
agent := vega.Agent{
    Name:   "assistant",
    Model:  "claude-sonnet-4-20250514",
    System: vega.NewSkillsPrompt(
        vega.StaticPrompt("You are a helpful assistant."),
        loader,
        vega.WithMaxActiveSkills(3),
    ),
}

Create skill files (skills/code-review.skill.md):

---
name: code-review
description: Expert code review guidance
tags: [code, review]
triggers:
  - type: keyword
    keywords: [review, PR, pull request, code review]
  - type: pattern
    pattern: "review (this|my) (code|changes)"
---

# Code Review Expert

When reviewing code, focus on:
1. Security vulnerabilities
2. Performance issues
3. Code clarity and maintainability
4. Test coverage

Or configure in YAML:

settings:
  skills:
    directories:
      - ./skills
      - ~/.vega/skills

agents:
  reviewer:
    model: claude-sonnet-4-20250514
    system: You are a code reviewer.
    skills:
      include: [code-review, security-*]
      exclude: [deprecated-*]
      max_active: 3

Skills are automatically matched and injected based on:

• keyword: Message contains specific words
• pattern: Message matches a regex pattern
• always: Always included

---

CLI Commands

# Run a workflow
vega run team.vega.yaml --workflow my-workflow --task "Do something"

# Validate a file
vega validate team.vega.yaml --verbose

# Interactive REPL
vega repl team.vega.yaml

# Web dashboard & REST API
vega serve team.vega.yaml
vega serve team.vega.yaml --addr :8080 --db my-data.db

# Show help
vega help

---

Examples

The examples/ directory contains complete working examples:

Example	Description
simple-agent.vega.yaml	Basic single-agent chatbot
code-review.vega.yaml	Two-agent code review workflow
dev-team.vega.yaml	Full dev team (architect, frontend, backend, reviewer, PM)
tools-demo.vega.yaml	Custom HTTP and exec tools
mcp-demo.vega.yaml	MCP server integration
skills-demo.vega.yaml	Dynamic skill injection
supervision-demo.vega.yaml	Fault tolerance patterns
control-flow.vega.yaml	Conditionals, loops, parallel execution

Run an example:

vega run examples/code-review.vega.yaml --workflow review --task "Write a binary search function"

---

DSL Reference

Settings

settings:
  default_model: claude-sonnet-4-20250514
  sandbox: ./workspace              # Restrict file operations
  budget: "$100.00"                 # Global budget limit

  mcp:                              # MCP server configuration
    servers:
      - name: filesystem
        transport: stdio            # stdio (default), http, sse
        command: npx
        args: ["-y", "@modelcontextprotocol/server-filesystem", "/workspace"]
        env:
          DEBUG: "true"
        timeout: 30s

  skills:                           # Global skill directories
    directories:
      - ./skills
      - ~/.vega/skills

  rate_limit:
    requests_per_minute: 60
    tokens_per_minute: 100000

Agents

agents:
  agent-name:
    model: claude-sonnet-4-20250514    # Required
    system: |                           # Required
      Your system prompt here.
    temperature: 0.7                    # Optional (0.0-1.0)
    tools:                              # Optional
      - read_file
      - write_file
      - filesystem__*                   # MCP tools (server__pattern)
    budget: "$5.00"                     # Optional
    supervision:                        # Optional
      strategy: restart
      max_restarts: 3
    skills:                             # Optional skill configuration
      directories:                      # Agent-specific skill dirs
        - ./agent-skills
      include: [coding-*, review]       # Only these skills
      exclude: [deprecated-*]           # Never these skills
      max_active: 3                     # Max skills to inject

Workflows

workflows:
  workflow-name:
    description: What this workflow does
    inputs:
      task:
        type: string
        required: true
        default: "default value"
    steps:
      - agent-name:
          send: "Message with {{task}} interpolation"
          save: variable_name
          timeout: 30s
    output: "{{variable_name}}"

Control Flow

# Conditionals
- if: "{{approved}}"
  then:
    - agent: ...
  else:
    - agent: ...

# Loops
- for: item in items
  steps:
    - agent:
        send: "Process {{item}}"

# Parallel
- parallel:
    - agent1: ...
    - agent2: ...

# Try/Catch
- try:
    - risky-agent: ...
  catch:
    - fallback-agent: ...

Expression Filters

{{name | upper}}           # UPPERCASE
{{name | lower}}           # lowercase
{{name | trim}}            # Remove whitespace
{{name | default:anon}}    # Default value
{{text | truncate:100}}    # Limit length
{{items | join:, }}        # Join array

---

Documentation

Document	Description
Quick Start	Get running in 5 minutes
Best Practices	Common pitfalls and how to avoid them
DSL Reference	Complete YAML syntax
Go Library Spec	Full API reference
Tools	Built-in and custom tools
MCP Servers	Model Context Protocol integration
Skills	Dynamic prompt injection
Supervision	Fault tolerance patterns
Architecture	Internal design
Web Dashboard	vega serve dashboard & REST API

---

Structured Logging

Vega uses Go's slog for structured logging. Enable debug logging to see detailed information:

import "log/slog"

// Enable debug logging
slog.SetLogLoggerLevel(slog.LevelDebug)

Log events include:

• Process spawn/complete/fail with agent names and IDs
• LLM call success/failure with latency, tokens, and error classification
• Retry attempts with backoff delays
• MCP server stderr output

Default Configuration

Vega provides sensible defaults that can be overridden:

// Default constants (defined in agent.go)
const (
    DefaultMaxIterations        = 50        // Tool call loop limit
    DefaultMaxContextTokens     = 100000    // Context window size
    DefaultLLMTimeout           = 5 * time.Minute
    DefaultStreamBufferSize     = 100
    DefaultSupervisorPollInterval = 100 * time.Millisecond
)

// Anthropic defaults (defined in llm/anthropic.go)
const (
    DefaultAnthropicTimeout = 5 * time.Minute
    DefaultAnthropicModel   = "claude-sonnet-4-20250514"
    DefaultAnthropicBaseURL = "https://api.anthropic.com"
)

---

Why Vega?

Erlang-Inspired Process Model

Most agent frameworks treat LLM calls as stateless functions. Vega models agents as processes with a full lifecycle (pending → running → completed/failed/timeout), managed by an Orchestrator. The key concepts ported from Erlang/OTP:

• Process Linking — Bidirectional links between processes. If one dies, the linked one dies too (unless it traps exits). This is how you build robust agent topologies where dependent agents fail together.
• Monitors — Unidirectional observation: watch another process and get notified when it exits, without dying yourself.
• TrapExit — A process can opt to receive exit signals as messages instead of dying. This is exactly how supervisors survive their children crashing.
• Supervision Trees — Strategies (Restart, Stop, Escalate, RestartAll) with configurable backoff (exponential, linear, constant with jitter) and windowed restart counting.

Just as Erlang/OTP made it possible to build telecom-grade systems by making processes and supervision cheap and composable, Vega applies the same philosophy to AI agent systems that need to run in production without falling over.

Agent = Blueprint, Process = Running Instance

The separation of Agent (a struct defining model, tools, system prompt, budget) from Process (a running instance with state, messages, metrics) means you can spawn multiple processes from the same agent definition, each with its own conversation history and lifecycle. This is the actor model applied to LLMs.

Intelligent Error Classification

Errors are automatically classified into 7 categories (RateLimit, Overloaded, Timeout, Temporary, InvalidRequest, Authentication, BudgetExceeded) with smart retry decisions. Rate limits and overloaded errors get retried with backoff; auth errors and bad requests don't. Production-grade reliability is built into the framework, not bolted on.

Team Delegation with Shared Blackboard

Agents can delegate to team members via a delegate tool with context-aware message enrichment — recent conversation history is forwarded so delegates understand the full picture. A shared blackboard (bb_read, bb_write, bb_list) gives team members structured shared state, not just text passed back and forth.

Dual Interface: Go Library + YAML DSL

The Go library gives full programmatic control, while the YAML DSL lets non-programmers define multi-agent workflows with control flow (if/then/else, for-each, parallel, try/catch), variable interpolation, and expression filters. The DSL interpreter is a proper workflow engine — not a thin config wrapper.

Everything is Observable

Built-in web dashboard with SSE streaming, process explorer, spawn tree visualization, cost tracking, and a chat UI with inline tool call panels. Processes emit structured events (text_delta, tool_start, tool_end), and the ChatStream API makes it straightforward to build rich streaming interfaces.

Feature Comparison

Feature	Raw SDK	Other Frameworks	Vega
Supervision trees	Manual	❌	✅ Built-in
Process linking & monitors	❌	❌	✅ Erlang-style
Automatic retries	Manual	Partial	✅ Smart (error-classified)
Rate limiting	Manual	Manual	✅ Built-in
Cost tracking	Manual	Partial	✅ Built-in
MCP server support	Manual	Partial	✅ Built-in
Web dashboard	❌	❌	✅ Built-in
Team delegation & blackboard	❌	❌	✅ Built-in
Dynamic skills	❌	❌	✅ Built-in
Conversation history	Manual	Manual	✅ WithMessages, persistence helpers
Context compaction	❌	❌	✅ Auto-summarization
Structured logging	Manual	Partial	✅ slog integration
Error classification	❌	❌	✅ 7 error classes
Non-programmer friendly	❌	❌	✅ YAML DSL
Parallel execution	Complex	Complex	✅ parallel:
Config-driven	❌	Limited	✅ Full YAML
Agent creation via chat	❌	❌	✅ Mother (built-in)
Cross-agent orchestration	Manual	❌	✅ Hermes (built-in)
Telegram channel	❌	❌	✅ Built-in (long polling)

---

Project Structure

vega/
├── agent.go           # Agent definition, context managers, defaults
├── context.go         # TokenBudgetContext, message serialization
├── process.go         # Running process with lifecycle, retry logic, spawn tree tracking
├── orchestrator.go    # Process management, spawn options, groups
├── supervision.go     # Fault tolerance, health monitoring
├── tools.go           # Tool registration, HTTP/exec executors
├── mcp_tools.go       # MCP server integration
├── skills.go          # Skills prompt wrapper
├── llm.go             # LLM interface, cost calculation
├── errors.go          # Error types, classification, retry decisions
├── llm/
│   └── anthropic.go   # Anthropic backend with streaming
├── mcp/               # Model Context Protocol client
│   ├── types.go       # MCP types and JSON-RPC
│   ├── client.go      # MCP client implementation
│   ├── transport_stdio.go  # Subprocess transport with logging
│   └── transport_http.go   # HTTP/SSE transport
├── skills/            # Agent skills system
│   ├── types.go       # Skill and trigger types
│   ├── parser.go      # SKILL.md file parser
│   ├── loader.go      # Directory scanner
│   └── matcher.go     # Keyword/pattern matching
├── container/         # Docker container management
│   ├── manager.go     # Container lifecycle
│   └── project.go     # Project isolation
├── serve/             # Web dashboard & REST API
│   ├── server.go      # HTTP server, routes, CORS
│   ├── handlers_api.go    # REST endpoint handlers
│   ├── handlers_sse.go    # Server-Sent Events stream
│   ├── broker.go      # Event pub/sub for SSE
│   ├── store.go       # Persistence interface
│   ├── store_sqlite.go    # SQLite implementation
│   ├── types.go       # API request/response types
│   ├── telegram.go    # Telegram bot via long polling
│   ├── embed.go       # Embedded SPA frontend
│   └── frontend/      # React + Vite + Tailwind dashboard
├── dsl/
│   ├── types.go       # AST types
│   ├── parser.go      # YAML parser
│   ├── interpreter.go # Workflow execution
│   ├── mother.go      # Mother meta-agent (creates/manages agents)
│   └── hermes.go      # Hermes meta-agent (orchestrates across all agents)
├── cmd/vega/
│   ├── main.go        # CLI entry point
│   └── serve.go       # serve command
├── examples/          # Example .vega.yaml files
└── docs/              # Documentation

---

Contributing

Contributions welcome! Please read the code, write tests, and submit PRs.

# Run tests
go test ./...

# Build CLI
go build -o vega ./cmd/vega

---

License

MIT