Parameters - Traffical

A parameter is a typed configuration value with a default. Parameters are the atomic unit in Traffical: experiments, feature flags, rollouts, and adaptive optimization are all policies that override parameter values for selected users.

Parameter types

Every parameter has a type that determines what values it can hold.

String
Number
Boolean
JSON

button.color:
  type: string
  default: "#1E6EFB"
  description: Primary button color on checkout

Use for colors, labels, copy, URLs, template names, anything textual.

discount_pct:
  type: number
  default: 0
  constraints:
    min: 0
    max: 50

Use for prices, percentages, thresholds, weights, timeouts. Supports min and max constraints.

show_trust_badges:
  type: boolean
  default: false

Use for feature flags and simple toggles. A boolean parameter under a rollout policy is functionally a feature flag.

hero_config:
  type: json
  default:
    headline: Welcome back
    showBanner: true
    maxItems: 5

Use for structured configuration where a single parameter controls several related settings together.

Namespaces

Parameter keys use dot notation to create logical groupings:

checkout.button.color
checkout.headline
checkout.show_trust_badges
pricing.discount_pct
homepage.hero_config

Namespaces are a convention — they have no runtime semantics — but they map directly onto how the CLI organizes parameters in .traffical/config.yaml and onto how the dashboard displays them. Group related parameters under a shared prefix so they stay together.

Default values

Every parameter has a default. The SDK returns the default whenever no policy overrides it for the current user — and as a safety net when the bundle hasn’t loaded yet or Traffical is unreachable. Defaults appear in two places:

In Traffical — the canonical value, set in the dashboard or via the CLI.
In your code — a fallback you pass into getParams. This is what your application sees if no bundle is available at all (first call before the network completes, offline, etc.).

const params = traffical.getParams({
  context: { userId: "user_789" },
  defaults: {
    "checkout.button.color": "#1E6EFB",
  },
});

If a parameter exists in the bundle, the resolved bundle value wins. If it doesn’t, the code default is returned. Always pass code defaults for every parameter you read — your app keeps working even if Traffical doesn’t.

Constraints

Parameters can declare optional constraints. They’re enforced at edit time (in the dashboard and in traffical push) but not at SDK resolution.

Constraint	Applies to	Description
`min`	number	Minimum allowed value
`max`	number	Maximum allowed value
`pattern`	string	Regex that values must match
`allowedValues`	string, number	Enum of permitted values

Config-as-code

Parameters can live in .traffical/config.yaml alongside your application code and sync with Traffical via the CLI:

version: "1.0"

parameters:
  feature_enabled:
    type: boolean
    default: false
    description: Master toggle for the new feature

namespaces:
  checkout:
    parameters:
      button.color:
        type: string
        default: "#1E6EFB"
      show_trust_badges:
        type: boolean
        default: false

  pricing:
    parameters:
      discount_pct:
        type: number
        default: 0
        constraints:
          min: 0
          max: 50

events:
  purchase:
    valueType: currency
    unit: USD

Run traffical push to sync. Parameters managed via the CLI are marked as synced in the dashboard — their definitions become read-only in the UI to prevent drift between your repo and the platform. Policies and allocations still live in the dashboard; the CLI manages parameter definitions and event schemas.

How parameters relate to other concepts

Layers — every parameter belongs to exactly one layer. Layers exist so concurrent experiments don’t interfere.
Policies — policies override parameter defaults for users matching their conditions and falling in their bucket ranges.
Events — track events let the optimization engine learn which parameter values perform best.

​Parameter types

​Namespaces

​Default values

​Constraints

​Config-as-code

​How parameters relate to other concepts