n8n-code-javascript

Name: n8n-code-javascript
Author: czlonkowski

5.0kinstalls983forks

How to install n8n-code-javascript?

czlonkowski/n8n-skills/n8n-code-javascript

$npx -y skills add czlonkowski/n8n-skills --skill n8n-code-javascript

Installs into the current project.

Summary

Write JavaScript code in n8n Code nodes. Use when writing JavaScript in n8n, using $input/$json/$node syntax, making HTTP requests with this.helpers / the $helpers global, working with dates using DateTime, troubleshooting Code node errors, choosing between Code node modes, or do

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SKILL.md

1	# JavaScript Code Node
2
3	Expert guidance for writing JavaScript code in n8n Code nodes.
4
5	---
6
7	## Quick Start
8
9	```javascript
10	// Basic template for Code nodes
11	const items = $input.all();
12
13	// Process data
14	const processed = items.map(item => ({
15	json: {
16	...item.json,
17	processed: true,
18	timestamp: new Date().toISOString()
19	}
20	}));
21
22	return processed;
23	```
24
25	### Essential Rules
26
27	1. Choose "Run Once for All Items" mode (recommended for most use cases)
28	2. Access data: `$input.all()`, `$input.first()`, or `$input.item`
29	3. Return `[{json: {...}}]` — the canonical, mode-portable form. In Run Once for All Items mode n8n also auto-wraps a bare `return {…}` object, so that runs too; what genuinely fails is returning a primitive (string/number) or `null`.
30	4. CRITICAL: Webhook data is under `$json.body` (not `$json` directly)
31	5. Built-ins available: `this.helpers.httpRequest()` (no auth — the bare `$helpers` global is undefined in the task-runner sandbox, so `$helpers.httpRequest()` throws `ReferenceError: $helpers is not defined`), DateTime (Luxon), $jmespath(). Not available: `this.helpers.httpRequestWithAuthentication` (deny-listed), $env (when N8N_BLOCK_ENV_ACCESS_IN_NODE=true), require() (unless allowlisted). For anything beyond a trivial unauthenticated GET (auth, pagination, retries), prefer the HTTP Request node and keep Code nodes for pure logic.
32	6. Instance-allowlisted libraries: Self-hosted instances can allowlist modules via `N8N_RUNNERS_ALLOWED_BUILT_IN_MODULES` and `N8N_RUNNERS_ALLOWED_EXTERNAL_MODULES` (legacy: `NODE_FUNCTION_ALLOW_BUILTIN` / `NODE_FUNCTION_ALLOW_EXTERNAL`). If the user says their instance allows specific modules (e.g. `axios`, `lodash`, `crypto`), use them via `require()` — don't refuse. If unsure, ask or default to built-ins only.
33	7. Wrong skill? If you're writing code for a Custom Code Tool attached to an AI Agent (`@n8n/n8n-nodes-langchain.toolCode`), stop — that node has a different contract (input via `query`, must return a string, no `$input`/`$helpers`). Use the n8n-code-tool skill.
34
35	---
36
37	## Mode Selection Guide
38
39	The Code node offers two execution modes. Choose based on your use case:
40
41	### Run Once for All Items (Recommended - Default)
42
43	Use this mode for: 95% of use cases
44
45	- How it works: Code executes once regardless of input count
46	- Data access: `$input.all()` or `items` array
47	- Best for: Aggregation, filtering, batch processing, transformations, API calls with all data
48	- Performance: Faster for multiple items (single execution)
49
50	```javascript
51	// Example: Calculate total from all items
52	const allItems = $input.all();
53	const total = allItems.reduce((sum, item) => sum + (item.json.amount \|\| 0), 0);
54
55	return [{
56	json: {
57	total,
58	count: allItems.length,
59	average: total / allItems.length
60	}
61	}];
62	```
63
64	When to use:
65	- ✅ Comparing items across the dataset
66	- ✅ Calculating totals, averages, or statistics
67	- ✅ Sorting or ranking items
68	- ✅ Deduplication
69	- ✅ Building aggregated reports
70	- ✅ Combining data from multiple items
71
72	### Run Once for Each Item
73
74	Use this mode for: Specialized cases only
75
76	- How it works: Code executes separately for each input item
77	- Data access: `$input.item` or `$item`
78	- Best for: Item-specific logic, independent operations, per-item validation
79	- Performance: Slower for large datasets (multiple executions)
80
81	```javascript
82	// Example: Add processing timestamp to each item
83	const item = $input.item;
84
85	return [{
86	json: {
87	...item.json,
88	processed: true,
89	processedAt: new Date().toISOString()
90	}
91	}];
92	```
93
94	When to use:
95	- ✅ Each item needs independent API call
96	- ✅ Per-item validation with different error handling
97	- ✅ Item-specific transformations based on item properties
98	- ✅ When items must be processed separately for business logic
99
100	Decision Shortcut:
101	- Need to look at multiple items? → Use "All Items" mode
102	- Each item completely independent? → Use "Each Item" mode

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Type

n8n-code-javascript

5.0kinstalls983forks

View on GitHub

How to install n8n-code-javascript?

czlonkowski/n8n-skills/n8n-code-javascript

$npx -y skills add czlonkowski/n8n-skills --skill n8n-code-javascript

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# JavaScript Code Node
2
3	Expert guidance for writing JavaScript code in n8n Code nodes.
4
5	---
6
7	## Quick Start
8
9	```javascript
10	// Basic template for Code nodes
11	const items = $input.all();
12
13	// Process data
14	const processed = items.map(item => ({
15	json: {
16	...item.json,
17	processed: true,
18	timestamp: new Date().toISOString()
19	}
20	}));
21
22	return processed;
23	```
24
25	### Essential Rules
26
27	1. Choose "Run Once for All Items" mode (recommended for most use cases)
28	2. Access data: `$input.all()`, `$input.first()`, or `$input.item`
29	3. Return `[{json: {...}}]` — the canonical, mode-portable form. In Run Once for All Items mode n8n also auto-wraps a bare `return {…}` object, so that runs too; what genuinely fails is returning a primitive (string/number) or `null`.
30	4. CRITICAL: Webhook data is under `$json.body` (not `$json` directly)
31	5. Built-ins available: `this.helpers.httpRequest()` (no auth — the bare `$helpers` global is undefined in the task-runner sandbox, so `$helpers.httpRequest()` throws `ReferenceError: $helpers is not defined`), DateTime (Luxon), $jmespath(). Not available: `this.helpers.httpRequestWithAuthentication` (deny-listed), $env (when N8N_BLOCK_ENV_ACCESS_IN_NODE=true), require() (unless allowlisted). For anything beyond a trivial unauthenticated GET (auth, pagination, retries), prefer the HTTP Request node and keep Code nodes for pure logic.
32	6. Instance-allowlisted libraries: Self-hosted instances can allowlist modules via `N8N_RUNNERS_ALLOWED_BUILT_IN_MODULES` and `N8N_RUNNERS_ALLOWED_EXTERNAL_MODULES` (legacy: `NODE_FUNCTION_ALLOW_BUILTIN` / `NODE_FUNCTION_ALLOW_EXTERNAL`). If the user says their instance allows specific modules (e.g. `axios`, `lodash`, `crypto`), use them via `require()` — don't refuse. If unsure, ask or default to built-ins only.
33	7. Wrong skill? If you're writing code for a Custom Code Tool attached to an AI Agent (`@n8n/n8n-nodes-langchain.toolCode`), stop — that node has a different contract (input via `query`, must return a string, no `$input`/`$helpers`). Use the n8n-code-tool skill.
34
35	---
36
37	## Mode Selection Guide
38
39	The Code node offers two execution modes. Choose based on your use case:
40
41	### Run Once for All Items (Recommended - Default)
42
43	Use this mode for: 95% of use cases
44
45	- How it works: Code executes once regardless of input count
46	- Data access: `$input.all()` or `items` array
47	- Best for: Aggregation, filtering, batch processing, transformations, API calls with all data
48	- Performance: Faster for multiple items (single execution)
49
50	```javascript
51	// Example: Calculate total from all items
52	const allItems = $input.all();
53	const total = allItems.reduce((sum, item) => sum + (item.json.amount \|\| 0), 0);
54
55	return [{
56	json: {
57	total,
58	count: allItems.length,
59	average: total / allItems.length
60	}
61	}];
62	```
63
64	When to use:
65	- ✅ Comparing items across the dataset
66	- ✅ Calculating totals, averages, or statistics
67	- ✅ Sorting or ranking items
68	- ✅ Deduplication
69	- ✅ Building aggregated reports
70	- ✅ Combining data from multiple items
71
72	### Run Once for Each Item
73
74	Use this mode for: Specialized cases only
75
76	- How it works: Code executes separately for each input item
77	- Data access: `$input.item` or `$item`
78	- Best for: Item-specific logic, independent operations, per-item validation
79	- Performance: Slower for large datasets (multiple executions)
80
81	```javascript
82	// Example: Add processing timestamp to each item
83	const item = $input.item;
84
85	return [{
86	json: {
87	...item.json,
88	processed: true,
89	processedAt: new Date().toISOString()
90	}
91	}];
92	```
93
94	When to use:
95	- ✅ Each item needs independent API call
96	- ✅ Per-item validation with different error handling
97	- ✅ Item-specific transformations based on item properties
98	- ✅ When items must be processed separately for business logic
99
100	Decision Shortcut:
101	- Need to look at multiple items? → Use "All Items" mode
102	- Each item completely independent? → Use "Each Item" mode

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6 picks

Type