Branch A ──┐
           ├─→ [NoOp: Combine Inputs] ──→ Downstream nodes use $('Combine Inputs').item.json.x
Branch B ──┘

// Set node: "Normalize Inputs"
name: `={{ $('Lookup by Email').item.json.name || $('Lookup by ID').item.json.full_name }}`
email: `={{ $('Lookup by Email').item.json.email || $('Lookup by ID').item.json.contact_email }}`

Webhook → Set: { customer_id: $json.body.customer_id, amount: $json.body.amount }
       → Postgres: WHERE id = {{ $json.customer_id }}
       → Email: Total is {{ $json.amount }}

Webhook → Postgres: WHERE id = {{ $('Webhook').item.json.body.customer_id }}
       → Email: Total is {{ $('Webhook').item.json.body.amount }}

{{ $json.name.toUpperCase() }}
{{ $json.email.toLowerCase().trim() }}
{{ $json.items.length }}
{{ $json.user.first_name + ' ' + $json.user.last_name }}
{{ `(${$json.user.phone.slice(0, 3)}) ${$json.user.phone.slice(3, 6)}-${$json.user.phone.slice(6, 10)}` }}

{{ $json.tags.filter(tag => tag.active).map(tag => tag.name).join(', ') }}
{{ Object.values($json.scores).reduce((sum, score) => sum + score, 0) }}

// Find one matching item from another node's output
{{ $('Get Models').all().find(model => model.json.id === $json.modelId).json.modelName }}

// Filter array, then check shape
{{
  $('Get User\'s Entries').all()
    .map(item => item.json)
    .filter(entry => entry.prize_eligible === 'eligible')
    .length > 0
}}

{{
  // Find all entries that are still processing AFTER 1 hour
  // (used to allow re-submission since something likely went wrong)
  $('Get User\'s Entries').all()
    .map(item => item.json)
    .filter(entry =>
      entry.prize_eligible === 'processing' &&
      $now.diffTo(entry.created_at, 'minutes') > 60
    )
    .length > 0
}}

const aggregateNode = node({
    type: 'n8n-nodes-base.set',
    config: {
        executeOnce: true,            // important when using .all() in expressions
        parameters: {
            assignments: {
                assignments: [
                    {
                        name: 'totalEligible',
                        value: `={{
                            $('Get Entries').all()
                                .map(item => item.json)
                                .filter(entry => entry.eligible)
                                .length
                        }}`,
                        type: 'number',
                    },
                ],
            },
        },
    },
})

// Workflow: Get Tags (200 items) → Search Posts (10 items) → this Set Fields node.
// Each post carries a `tag_ids` array. Set Fields runs per-item (10 times)
// and resolves each post's tag_ids into the full tag objects.
tags: ={{
  $('Get Tags').all()
    .filter(tag => $('Search Posts').item.json.tag_ids.includes(tag.json.id))
}}

{{ $json.status === 'active' ? 'Active' : 'Inactive' }}
{{ $json.amount >= 100 ? 'Large' : ($json.amount >= 10 ? 'Medium' : 'Small') }}

{{ DateTime.now().toISO() }}
{{ DateTime.fromISO($json.created_at).toFormat('yyyy-MM-dd') }}
{{ DateTime.now().minus({ days: 7 }).startOf('day').toISO() }}
{{ DateTime.fromISO($json.due).diffNow('days').days }}    // days from now (negative if past)

{{ $('Webhook Trigger').item.json.body.customer_id }}
{{ $('Lookup customer').item.json.email }}
{{ $('Combine Inputs').item.json.coupon_code }}    // NoOp convergence point

{{ (() => {
    // Compute total including tax
    const items = $json.line_items
    const subtotal = items.reduce((sum, item) => sum + item.price * item.qty, 0)
    const tax = subtotal * 0.08
    return (subtotal + tax).toFixed(2)
})() }}

{{ (() => $json.text.replace(/\b(?:foo|bar)\b/gi, 'baz'))() }}

{{ $json.id || "fallback-id-here" }}

{{ $json.user?.profile?.id ?? "anonymous" }}

// String literal (default behavior)
foo: 'plain string'

// Number
foo: '={{ 100 }}'

// Boolean
foo: '={{ true }}'

// Object (the `={{ ... }}` is what makes the receiver see an object, not a string)
foo: '={{ { "valid": true, "items": [] } }}'

// Array
foo: '={{ ["a", "b", "c"] }}'

// Reference to another node's value (preserves whatever type that value already is)
foo: '={{ $("Source Node").item.json.payload }}'

// WRONG
foo: '={{ $json.payload }}'

// RIGHT
foo: '={{ $("Source Node").item.json.payload }}'

{{
  // Default to avoid query errors when user_id is missing.
  // The fallback UUID is a known-empty row.
  $json.id || "305f7106-6988-4651-b26a-18979641b7b5"
}}

1. Single-field transform → expression in the field
2. Multi-step pure logic on one item → arrow function in Edit Fields
3. Multi-source aggregation, libraries, or stateful → Code node