ChainGraph Core Concepts

ChainGraph is a flow-based programming framework for building visual computational graphs. This skill covers the fundamental domain concepts that ALL agents need to understand.

The Four Core Abstractions

┌─────────────────────────────────────────────────────────────┐
│                         FLOW                                │
│  (Directed Acyclic Graph - the container)                   │
│                                                             │
│   ┌─────────┐         ┌─────────┐         ┌─────────┐      │
│   │  NODE   │         │  NODE   │         │  NODE   │      │
│   │ ┌─────┐ │  EDGE   │ ┌─────┐ │  EDGE   │ ┌─────┐ │      │
│   │ │PORT │─┼────────▶│ │PORT │─┼────────▶│ │PORT │ │      │
│   │ └─────┘ │         │ └─────┘ │         │ └─────┘ │      │
│   └─────────┘         └─────────┘         └─────────┘      │
│                                                             │
└─────────────────────────────────────────────────────────────┘

1. Flow

A Flow is a directed acyclic graph (DAG) containing interconnected nodes and edges that define a computational workflow.

Key Properties

id

metadata

nodes

edges

Key Methods

// Add a node to the flow
flow.addNode(node: INode): Promise<INode>

// Connect two ports via edge
flow.connectPorts(sourceNodeId, sourcePortId, targetNodeId, targetPortId): Edge

// Subscribe to flow events
flow.onEvent(handler: (event: FlowEvent) => void): () => void

// Validate entire flow
flow.validate(): Promise<FlowValidationResult>

Key Files

packages/chaingraph-types/src/flow/flow.ts:42

packages/chaingraph-types/src/flow/interface.ts:19-193

packages/chaingraph-types/src/flow/types.ts:12-54

2. Node

A Node is a discrete computational unit that performs a specific operation on input data and produces output. Nodes are the building blocks of flows.

Node Lifecycle

Idle → Ready → Executing → Completed
                    ↓
                  Error

NodeStatus Enum

enum NodeStatus {
  Idle = 'idle',           // Initial state
  Initialized = 'initialized',
  Ready = 'ready',         // Ready to execute
  Pending = 'pending',     // Waiting for dependencies
  Executing = 'executing', // Currently running
  Completed = 'completed', // Successfully finished
  Skipped = 'skipped',     // Skipped (condition not met)
  Error = 'error',         // Failed with error
  Disposed = 'disposed',   // Cleaned up
}

Key Properties

id

metadata

status

ports

Key Methods

// Execute the node
node.execute(context: ExecutionContext): Promise<NodeExecutionResult>

// Get a port by ID
node.getPort(portId: string): IPort | undefined

// Validate configuration
node.validate(): Promise<NodeValidationResult>

// Reset to initial state
node.reset(): Promise<void>

NodeMetadata

interface NodeMetadata {
  type: string           // Node class name (required)
  title?: string         // Display name
  category?: NodeCategory // e.g., 'math', 'flow-control', 'ai'
  description?: string
  version?: number
  icon?: string
  tags?: string[]
  parentNodeId?: string  // If nested in group
  ui?: NodeUIMetadata    // Position, dimensions, etc.
}

Key Files

packages/chaingraph-types/src/node/base-node.ts

packages/chaingraph-types/src/node/interface.ts:11-14

packages/chaingraph-types/src/node/node-enums.ts:12-22

packages/chaingraph-types/src/node/types.ts:17-31

3. Port

A Port is a typed input or output connector on a Node through which data flows. Ports are strongly typed and support primitives, arrays, objects, and streams.

Port Direction

type PortDirection = 'input' | 'output' | 'passthrough'

• Input: Receives data from connected output ports
• Output: Sends data to connected input ports
• Passthrough: Both input and output

Port Types (9 Total)

string

number

boolean

array

object

stream

enum

secret

any

Port Configuration

Each port type has a specific config interface:

interface StringPortConfig {
  type: 'string'
  defaultValue?: string
  minLength?: number
  maxLength?: number
  pattern?: RegExp  // Validation regex
}

interface NumberPortConfig {
  type: 'number'
  defaultValue?: number
  min?: number
  max?: number
  step?: number
  integer?: boolean
}

interface ArrayPortConfig<Item> {
  type: 'array'
  itemConfig: IPortConfig  // Type of each item
  minLength?: number
  maxLength?: number
  isMutable?: boolean      // Can items be added/removed?
}

interface ObjectPortConfig<Schema> {
  type: 'object'
  schema: IObjectSchema    // Properties definition
  isSchemaMutable?: boolean
}

Key Methods

// Get/set port value
port.getValue(): T | undefined
port.setValue(value: T): void

// Validation
port.validate(): boolean

// Serialization
port.serialize(): JSONValue
port.deserialize(data: JSONValue): IPort

// Connection management
port.addConnection(nodeId: string, portId: string): void
port.removeConnection(nodeId: string, portId: string): void

Key Files

packages/chaingraph-types/src/port/base/IPort.ts:30-187

packages/chaingraph-types/src/port/base/types.ts:84-213

packages/chaingraph-types/src/port/instances/

packages/chaingraph-types/src/port/plugins/

4. Edge

An Edge is a directed connection from an output port of one node to an input port of another node, enabling data flow.

Edge Status

enum EdgeStatus {
  Active = 'active',     // Connection working
  Inactive = 'inactive', // Disabled
  Error = 'error',       // Transfer failed
}

Key Properties

id

sourceNode

sourcePort

targetNode

targetPort

metadata

EdgeMetadata

interface EdgeMetadata {
  label?: string              // Display label
  anchors?: EdgeAnchor[]      // Control points for custom paths
  version?: number            // For optimistic updates
}

interface EdgeAnchor {
  id: string
  x: number                   // Coordinate
  y: number
  index: number               // Order in path
}

Key Files

packages/chaingraph-types/src/edge/edge.ts:18

packages/chaingraph-types/src/edge/interface.ts:16-65

packages/chaingraph-types/src/edge/types.ts:12-54

5. Execution

ExecutionContext

The runtime context provided to every executing node:

class ExecutionContext {
  readonly executionId: string      // Unique run ID
  readonly rootExecutionId?: string // Root workflow ID
  readonly parentExecutionId?: string // Parent ID (for children)
  readonly flowId?: string
  readonly userId?: string
  readonly startTime: Date
  readonly abortController: AbortController
  readonly integrations: IntegrationContext  // AI, wallet, etc.
  readonly executionDepth: number  // Prevents infinite recursion (max 100)

  // Event emission (for event-driven execution)
  emitEvent(eventType: string, data: any, nodeId: string): void

  // Port resolution (for stream ports)
  resolvePort(nodeId: string, portId: string): void
  isPortResolved(nodeId: string, portId: string): boolean

  // Get integration data
  getIntegration<T>(type: string): T | undefined
}

ExecutionEngine

Orchestrates flow execution:

class ExecutionEngine {
  constructor(flow: Flow, context: ExecutionContext, options?: ExecutionOptions)

  async execute(): Promise<void>

  // Control flow
  pause(): void
  resume(): void
  stop(reason?: string): void

  // Event handling
  onEvent(eventType: ExecutionEventEnum, callback): void
  onError(callback): void
}

ExecutionOptions

interface ExecutionOptions {
  execution?: {
    maxConcurrency?: number    // Default: 50
    nodeTimeoutMs?: number     // Default: 3600000 (1 hour)
    flowTimeoutMs?: number     // Default: 10800000 (3 hours)
  }
  debug?: boolean              // Enable debugger
  breakpoints?: string[]       // Node IDs to break on
}

Key Files

packages/chaingraph-types/src/execution/execution-context.ts:37-320

packages/chaingraph-types/src/flow/execution-engine.ts:49

6. Events

Flow Events (FlowEventType)

Events emitted during flow editing (19 total):

FlowInitStart

FlowInitEnd

MetadataUpdated

NodesAdded

NodeAdded

NodeRemoved

NodesUpdated

NodeUpdated

NodeParentUpdated

PortCreated

PortUpdated

PortRemoved

EdgesAdded

EdgeAdded

EdgeRemoved

EdgeMetadataUpdated

NodeUIPositionChanged

NodeUIDimensionsChanged

NodeUIChanged

Execution Events (ExecutionEventEnum)

Events emitted during execution (21 total):

EXECUTION_CREATED

FLOW_SUBSCRIBED

FLOW_STARTED

FLOW_COMPLETED

FLOW_FAILED

FLOW_CANCELLED

FLOW_PAUSED

FLOW_RESUMED

NODE_STARTED

NODE_COMPLETED

NODE_FAILED

NODE_SKIPPED

NODE_STATUS_CHANGED

NODE_DEBUG_LOG_STRING

EDGE_TRANSFER_STARTED

EDGE_TRANSFER_COMPLETED

EDGE_TRANSFER_FAILED

CHILD_EXECUTION_SPAWNED

CHILD_EXECUTION_COMPLETED

CHILD_EXECUTION_FAILED

DEBUG_BREAKPOINT_HIT

Key Files

packages/chaingraph-types/src/flow/events.ts:17-47

packages/chaingraph-types/src/flow/execution-events.ts:15-48

Quick Reference

Creating a Node (with decorators)

import { Node, Input, Output, PortString, PortNumber } from '@badaitech/chaingraph-types'

@Node({
  title: 'Add Numbers',
  category: 'math',
  description: 'Adds two numbers',
})
class AddNode extends BaseNode {
  @Input()
  @PortNumber({ defaultValue: 0 })
  a: number = 0

  @Input()
  @PortNumber({ defaultValue: 0 })
  b: number = 0

  @Output()
  @PortNumber()
  result: number = 0

  async execute(context: ExecutionContext): Promise<NodeExecutionResult> {
    this.result = this.a + this.b
    return {}
  }
}

Data Flow Summary

1. Flow loads nodes and edges
2. ExecutionEngine resolves dependencies (topological sort)
3. Nodes execute in parallel where possible
4. Output port values transfer to connected input ports
5. Events stream in real-time
6. Flow completes or fails

Related Skills

• types-architecture

  - Deep dive into the types package

• port-system

  - Detailed port types and decorators

• effector-patterns

  - Frontend state management

• dbos-patterns

  - Backend durable execution