n8n-syntax-workflow-json

Quick Reference

Workflow JSON Top-Level Structure (IWorkflowBase)

Field	Type	Required	Purpose
id	string	YES	Unique workflow identifier
name	string	YES	Human-readable workflow name
active	boolean	YES	Whether workflow listens for triggers
isArchived	boolean	YES	Whether workflow is archived
nodes	INode[]	YES	Array of all nodes in the workflow
connections	IConnections	YES	Connection map between nodes
settings	IWorkflowSettings	NO	Workflow-level configuration
staticData	IDataObject	NO	Persistent data (polling state, etc.)
pinData	IPinData	NO	Pinned test data for manual execution
description	string | null	NO	Workflow description
versionId	string	NO	Version identifier
meta	WorkflowFEMeta	NO	Frontend metadata (template ID, etc.)

INode Fields

Field	Type	Required	Purpose
id	string	YES	Unique node ID (UUID format)
name	string	YES	Display name (MUST be unique in workflow)
type	string	YES	Node type (e.g., n8n-nodes-base.httpRequest)
typeVersion	number	YES	Node version number
position	[number, number]	YES	Canvas position [x, y]
parameters	INodeParameters	YES	Node parameter values
credentials	INodeCredentials	NO	Credential references
disabled	boolean	NO	Whether node is disabled
notes	string	NO	User-visible notes
notesInFlow	boolean	NO	Show notes on canvas
webhookId	string	NO	Webhook ID (webhook nodes only)
retryOnFail	boolean	NO	Retry on error
maxTries	number	NO	Max retry attempts
waitBetweenTries	number	NO	Milliseconds between retries
alwaysOutputData	boolean	NO	Output empty item if no data
executeOnce	boolean	NO	Execute only for first item
onError	OnError	NO	Error behavior strategy
continueOnFail	boolean	NO	Continue workflow on error

OnError Values

Value	Behavior
continueErrorOutput	Route to error output
continueRegularOutput	Route to regular output with error info
stopWorkflow	Stop entire workflow execution

NodeConnectionType Values

Constant	String Value	Purpose
NodeConnectionTypes.Main	"main"	Standard data flow
NodeConnectionTypes.AiAgent	"ai_agent"	AI agent connection
NodeConnectionTypes.AiChain	"ai_chain"	AI chain connection
NodeConnectionTypes.AiDocument	"ai_document"	AI document loader
NodeConnectionTypes.AiEmbedding	"ai_embedding"	AI embedding model
NodeConnectionTypes.AiLanguageModel	"ai_languageModel"	AI language model
NodeConnectionTypes.AiMemory	"ai_memory"	AI memory store
NodeConnectionTypes.AiOutputParser	"ai_outputParser"	AI output parser
NodeConnectionTypes.AiRetriever	"ai_retriever"	AI retriever
NodeConnectionTypes.AiReranker	"ai_reranker"	AI reranker
NodeConnectionTypes.AiTextSplitter	"ai_textSplitter"	AI text splitter
NodeConnectionTypes.AiTool	"ai_tool"	AI tool
NodeConnectionTypes.AiVectorStore	"ai_vectorStore"	AI vector store

Critical Warnings

NEVER use node id values as connection keys -- connections are keyed by node name, not ID. Using IDs silently produces broken workflows.

NEVER omit the type field in connection targets -- every IConnection object MUST have node, type, AND index. Missing type causes runtime errors.

NEVER duplicate node names within a workflow -- each name field MUST be unique. n8n uses names as connection keys, so duplicates break the connection map.

ALWAYS use the 3-level nesting for connections: sourceName → connectionType → outputIndex → targets[]. Flat or 2-level structures are invalid.

ALWAYS set typeVersion to a valid version for the node type. Omitting or using an unsupported version causes the node to fail silently or use unexpected defaults.

---

IConnections Format (3-Level Nesting)

This is the #1 source of errors when generating workflow JSON. The connection format uses three nesting levels:

Level 1: Source node NAME (string key)
  Level 2: Connection TYPE (string key, usually "main")
    Level 3: Output INDEX (array position)
      → Array of target connections [{node, type, index}]

TypeScript Interface

// Level 1: Keyed by SOURCE node name
interface IConnections {
    [sourceNodeName: string]: INodeConnections;
}

// Level 2: Keyed by connection type
interface INodeConnections {
    [connectionType: string]: NodeInputConnections;
}

// Level 3: Array indexed by output index
type NodeInputConnections = Array<IConnection[] | null>;

// Individual connection target
interface IConnection {
    node: string;           // Destination node NAME
    type: NodeConnectionType; // Connection type at destination
    index: number;          // Destination INPUT index
}

Visual Breakdown

{
    "connections": {
        "HTTP Request": {          // Level 1: source node name
            "main": [              // Level 2: connection type
                [                  // Level 3: output index 0
                    {
                        "node": "Set",       // target node name
                        "type": "main",      // target connection type
                        "index": 0           // target input index
                    }
                ]
            ]
        }
    }
}

Multi-Output Node (IF Node)

{
    "IF": {
        "main": [
            [{"node": "True Handler", "type": "main", "index": 0}],
            [{"node": "False Handler", "type": "main", "index": 0}]
        ]
    }
}

• Output index 0 = true branch → routes to "True Handler"
• Output index 1 = false branch → routes to "False Handler"

Fan-Out (One Output to Multiple Nodes)

{
    "Trigger": {
        "main": [
            [
                {"node": "Branch A", "type": "main", "index": 0},
                {"node": "Branch B", "type": "main", "index": 0}
            ]
        ]
    }
}

Multiple targets in the SAME output index array means parallel fan-out.

AI Node Connections

AI nodes use typed connections instead of "main":

{
    "OpenAI Chat Model": {
        "ai_languageModel": [
            [{"node": "AI Agent", "type": "ai_languageModel", "index": 0}]
        ]
    },
    "Calculator Tool": {
        "ai_tool": [
            [{"node": "AI Agent", "type": "ai_tool", "index": 0}]
        ]
    },
    "Window Buffer Memory": {
        "ai_memory": [
            [{"node": "AI Agent", "type": "ai_memory", "index": 0}]
        ]
    }
}

---

Workflow Settings

interface IWorkflowSettings {
    timezone?: 'DEFAULT' | string;              // e.g., "Europe/Amsterdam"
    errorWorkflow?: 'DEFAULT' | string;         // Workflow ID to run on error
    callerIds?: string;                         // Allowed caller workflow IDs
    callerPolicy?: CallerPolicy;                // Sub-workflow access
    saveDataErrorExecution?: SaveDataExecution;  // "all" | "none" | "DEFAULT"
    saveDataSuccessExecution?: SaveDataExecution;
    saveManualExecutions?: 'DEFAULT' | boolean;
    saveExecutionProgress?: 'DEFAULT' | boolean;
    executionTimeout?: number;                  // Timeout in seconds
    executionOrder?: 'v0' | 'v1';              // ALWAYS use 'v1' for new workflows
}

ALWAYS set executionOrder to "v1" for new workflows. The "v0" algorithm has known edge cases with complex branching.

---

Decision Tree: Building Workflow JSON

START: Creating workflow JSON
├── Define all nodes first
│   ├── Each node MUST have: id, name, type, typeVersion, position, parameters
│   ├── Each name MUST be unique across the workflow
│   └── Use UUID format for id fields
├── Build connections after nodes
│   ├── Is this a standard data flow?
│   │   └── YES → Use "main" as connection type
│   ├── Is this an AI sub-node connection?
│   │   └── YES → Use the specific ai_* connection type
│   ├── Does the source node have multiple outputs?
│   │   └── YES → Add entries at each output index position
│   └── Does one output go to multiple nodes?
│       └── YES → Add multiple targets in the same output index array
└── Add settings
    └── ALWAYS include executionOrder: "v1"

---

Reference Links

• references/methods.md -- IWorkflowBase, INode, IConnections, NodeConnectionType interface details
• references/examples.md -- Complete workflow JSON examples (minimal, multi-output, AI workflow)
• references/anti-patterns.md -- Common JSON structure mistakes and connection format errors

Official Sources

• https://docs.n8n.io/workflows/
• https://docs.n8n.io/api/
• https://github.com/n8n-io/n8n (packages/workflow/src/interfaces.ts)