condition

condition

A pure branching waypoint: evaluates a condition expression against the context and routes the request through the true or false port. It never mutates the request or response — use it to split a policy into two distinct paths (premium vs. standard upstreams, header-gated feature rollouts, body-shape-dependent pipelines).

Configuration

Key	Type	Default	Description
conditions	array (required, non-empty)	—	A condition expression: rules ANDed at the top level, nested AND/OR/NOT groups, variable and JSONPath body subjects.

type: condition
config:
  conditions:
    - ["$.user.tier", "==", "premium"]

conditions is parsed at config load — a malformed expression fails policy compilation, never a live request. An empty rule list is rejected too, since it would branch unconditionally.

Behavior

The expression grammar, operators, and evaluation semantics are shared with request-validation and every other node that takes a condition expression — evaluation is lenient:

• an absent variable subject (e.g. arg_interactive with no ?interactive= query param) evaluates as the empty string, so a positive comparison over it is simply false (and != is true); use the existence tests present / absent to branch on absence explicitly;
• a JSONPath subject over a body that is empty, not valid JSON, or whose path matches nothing, matches zero nodes — comparison rules are false, absent is true.

Evaluation is left-to-right with short-circuiting. The node itself never fails: the request always leaves on true or false.

The plugin does not write to context.message.

Ports

condition declares three output ports and no success port — the request always leaves on true or false, both mandatory: the policy compiler rejects any policy that leaves either unwired. error remains declared (so existing policies that wired it still compile) but the node never emits on it.

nodes:
  - id: tier-check
    type: condition
    config:
      conditions:
        - ["$.user.tier", "==", "premium"]

edges:
  - from: listener.out
    to: tier-check.in
  - from: tier-check.true
    to: premium-upstream.in
  - from: tier-check.false
    to: standard-upstream.in

Errors

This node never fails at execution time: it always returns through success, so its error port is never taken.