N8n Syntax Expressions

n8n-syntax-expressions

Quick Reference

Expression Syntax

All n8n expressions use double-curly-brace syntax inside node parameter fields:

{{ expression }}

Expressions support standard JavaScript operations plus n8n-specific built-in variables.

Current Node Input

| Variable | Returns | Description | |----------|---------|-------------| | $json | Object | Shorthand for $input.item.json — current item's JSON data | | $binary | Object | Shorthand for $input.item.binary — current item's binary data | | $input.item | Item | The input item currently being processed | | $input.all() | Array\ | All input items from the current node | | $input.first() | Item | First input item | | $input.last() | Item | Last input item | | $input.params | Object | Node configuration settings and operation parameters |

Other Node Output

| Variable | Returns | Description | |----------|---------|-------------| | $("node-name").all() | Array\ | All items from named node output | | $("node-name").first() | Item | First item from named node | | $("node-name").last() | Item | Last item from named node | | $("node-name").item | Item | Linked item via paired items tracking | | $("node-name").itemMatching(index) | Item | Traces back to matching item (preferred in Code node) | | $("node-name").params | Object | Query settings/parameters of named node | | $("node-name").context | Object | Only available with Loop Over Items node | | $("node-name").isExecuted | Boolean | True if the node has executed |

Workflow & Execution Metadata

| Variable | Returns | Description | |----------|---------|-------------| | $workflow.id | String | Workflow ID | | $workflow.name | String | Workflow name | | $workflow.active | Boolean | Whether workflow is active | | $execution.id | String | Unique execution ID | | $execution.mode | String | "test", "production", or "evaluation" | | $execution.resumeUrl | String | Webhook URL to resume at a Wait node | | $execution.resumeFormUrl | String | URL for Wait node form | | $execution.customData | CustomData | Get/set custom execution data |

Environment & Configuration

| Variable | Returns | Description | |----------|---------|-------------| | $env | Object | Instance environment variables | | $vars | Object | Active environment variables (all strings) | | $secrets | Object | External secrets (NOT available in Code node) |

Date & Time (Luxon DateTime)

| Variable | Returns | Description | |----------|---------|-------------| | $now | DateTime | Current moment, respects workflow timezone | | $today | DateTime | Midnight at start of current day |

Node Execution Context

| Variable | Returns | Description | |----------|---------|-------------| | $prevNode.name | String | Name of previous node | | $prevNode.outputIndex | Number | Output connector index | | $prevNode.runIndex | Number | Run of previous node | | $runIndex | Number | How many times current node has executed (zero-based) | | $itemIndex | Number | Current item position (NOT available in Code node) | | $parameter | Object | Configuration settings of current node | | $nodeVersion | Number | Current node version | | $pageCount | Number | Results pages fetched (HTTP Request node only) |

Utility Functions

| Function | Returns | Description | |----------|---------|-------------| | $ifEmpty(value, fallback) | any | Returns value if non-empty, otherwise fallback | | $jmespath(object, searchString) | any | JMESPath query on a JSON object | | $getWorkflowStaticData(type) | Object | Persistent data. Type: "global" or "node" |

HTTP Response (HTTP Request Node Only)

| Variable | Returns | Description | |----------|---------|-------------| | $response.body | Object | Response body from last HTTP call | | $response.headers | Object | Response headers | | $response.statusCode | Number | HTTP status code | | $response.statusMessage | String | Optional status message |

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Critical Warnings

NEVER use $itemIndex in the Code node -- it is NOT available there. Use a loop counter or items.indexOf() instead.

NEVER use $secrets in the Code node -- it is NOT available there. Pass secret values via node parameters or use $env / $vars instead.

NEVER reverse the parameter order of $jmespath() -- it is $jmespath(object, searchString), NOT $jmespath(searchString, object). The n8n implementation differs from the JMESPath specification's search(searchString, object) pattern.

NEVER use new Date() in expressions -- ALWAYS use Luxon's $now, $today, DateTime.fromISO(), or DateTime.fromFormat() for consistent timezone handling.

NEVER rely on $getWorkflowStaticData() during manual test executions -- static data requires an active workflow with a trigger or webhook.

NEVER store large data objects in workflow static data -- keep it small. Large data causes performance degradation.

ALWAYS use $json as the primary way to access current item data -- it is shorthand for $input.item.json.

ALWAYS use $("Node Name").item in expressions for linked item access. In Code nodes, use $("Node Name").itemMatching(index) instead.

ALWAYS use $ifEmpty(value, fallback) for safe null/undefined handling -- it covers "", [], {}, null, and undefined.

ALWAYS use bracket notation for dynamic property access: $json["field-with-dashes"].

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Essential Patterns

Pattern 1: Access Current Item Data

{{ $json.name }}
{{ $json.address.city }}
{{ $json["field-with-dashes"] }}

Pattern 2: Access Other Node Output

{{ $("HTTP Request").item.json.data }}
{{ $("Get Users").first().json.email }}
{{ $("Webhook").all().length }}

Pattern 3: Conditional Expressions

{{ $json.status === "active" ? "Yes" : "No" }}
{{ $ifEmpty($json.nickname, $json.fullName) }}

Pattern 4: JMESPath Query

{{ $jmespath($json.data, "[*].name") }}
{{ $jmespath($("Code").all(), "[?json.active==`true`].json.id") }}

Pattern 5: Date Operations (Luxon)

{{ $now.format("yyyy-MM-dd HH:mm:ss") }}
{{ $today.minus({days: 7}).toISO() }}
{{ $now.toRelative() }}

Pattern 6: Static Workflow Data (Persistence)

// In Code node — data persists across executions
const staticData = $getWorkflowStaticData('global');
const lastRun = staticData.lastExecution;
staticData.lastExecution = new Date().toISOString();
// n8n saves automatically on successful execution

Pattern 7: IIFE for Multi-Statement Expressions

{{ (function() { const x = $json.price * 1.21; return x.toFixed(2); })() }}

Pattern 8: Custom Execution Data

// Set data
$execution.customData.set("user_email", "me@example.com");
$execution.customData.setAll({"key1": "val1", "key2": "val2"});

// Get data
const email = $execution.customData.get("user_email");
const all = $execution.customData.getAll();

Pattern 9: Paired Items (Item Linking)

Every output item links back to the input items that produced it. This enables:

• Automatic item resolution in drag-and-drop mapping
• $("Node").item — access the linked item in expressions
• $("Node").itemMatching(index) — trace item origin in Code node

When a node processes multiple items, {{ $json.fruit }} dynamically resolves to each item's value during iteration.

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$ifEmpty Behavior

$ifEmpty(value, fallback) returns fallback when value is any of:

| Value | Considered Empty | |-------|-----------------| | "" | Yes | | [] | Yes | | {} | Yes | | null | Yes | | undefined | Yes | | 0 | No | | false | No |

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Expression Context Rules

| Context | Available Variables | |---------|-------------------| | Node parameter fields | ALL $ variables | | Code node (JavaScript) | ALL except $itemIndex and $secrets | | Code node (Python) | _ prefix variants (e.g., _json, _env, _vars) | | Credential fields | $credentials object only | | HTTP Request node | ALL plus $response and $pageCount | | Loop Over Items | ALL plus $("Loop Node").context |

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Reference Links

• [references/methods.md](references/methods.md) -- All $ variables with signatures, return types, descriptions
• [references/examples.md](references/examples.md) -- Expression patterns, JMESPath, static data, IIFE patterns
• [references/anti-patterns.md](references/anti-patterns.md) -- Expression mistakes, context confusion

Official Sources

• https://docs.n8n.io/code/expressions/
• https://docs.n8n.io/code/builtin/overview/
• https://docs.n8n.io/code/builtin/current-node-input/
• https://docs.n8n.io/code/builtin/output-other-nodes/
• https://docs.n8n.io/code/builtin/n8n-metadata/
• https://docs.n8n.io/data/jmespath/

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Impertio-Studio
• Source: Impertio-Studio/n8n-Claude-Skill-Package
• License: MIT

Install and usage instructions live in the source repository linked above.