Conditions

Links support MongoDB-style when conditions to control routing based on node output.

Operators

Operator	Example	Description
(none)	`{ status: "ok" }`	Exact equality
`gt`	`{ count: { gt: 5 } }`	Greater than
`gte`	`{ count: { gte: 5 } }`	Greater or equal
`lt`	`{ count: { lt: 10 } }`	Less than
`lte`	`{ count: { lte: 10 } }`	Less or equal
`ne`	`{ status: { ne: "error" } }`	Not equal
`in`	`{ role: { in: ["admin", "mod"] } }`	Value in array
`exists`	`{ token: { exists: true } }`	Field exists
`regex`	`{ token: { regex: "^ok" } }`	Regex match
`or`	`{ or: [{...}, {...}] }`	Logical OR

Logic

All top-level fields are AND (all must match)
Use or for OR logic
Conditions are evaluated against the source node's output

Examples

Simple equality

{ "status": "ok" }

Matches if output contains { "status": "ok" }.

Multiple conditions (AND)

{ "status": "ok", "count": { "gte": 10 } }

Matches if status is "ok" AND count is >= 10.

OR logic

{
  "or": [
    { "status": "ok" },
    { "status": "warning" }
  ]
}

Matches if status is "ok" OR "warning".

Field existence

{ "token": { "exists": true } }

Matches if the output has a token field (any value).

{ "error": { "exists": false } }

Matches if the output does NOT have an error field.

Membership

{ "role": { "in": ["admin", "moderator", "owner"] } }

Matches if role is one of the listed values.

Regex match

{ "email": { "regex": "@company\\.com$" } }

Matches if email ends with @company.com. Uses JavaScript RegExp.

Numeric range

{ "score": { "gte": 0, "lte": 100 } }

Matches if score is between 0 and 100.

Not equal

{ "status": { "ne": "error" } }

Matches if status is anything except "error".

Usage in links

workflow.json

{
  "links": [
    {
      "from": "validate",
      "to": "process",
      "when": { "valid": true, "score": { "gte": 80 } }
    },
    {
      "from": "validate",
      "to": "reject",
      "when": { "valid": { "ne": true } }
    }
  ]
}

SDK

wf.addLink({
  from: validate.id,
  to: process.id,
  when: { valid: true, score: { gte: 80 } },
});

Validation

Conditions are validated when a link is added. Unknown operators throw LinkValidationError:

Link "my-link" has invalid 'when' condition: Unknown operator: foo

On this page