Profiles

Profiles allow you to parameterize decisions without changing logic.

What Are Profiles?

A profile contains the variable parameters for a decision:

// Same decision logic, different thresholds
const usProfile = {
  highThreshold: 10000,
  mediumThreshold: 5000,
};

const euProfile = {
  highThreshold: 8000,
  mediumThreshold: 3000,
};

Why Use Profiles?

• Regional variations - Different rules per country/region
• Customer tiers - Premium vs standard thresholds
• Environments - Stricter limits in production
• A/B testing - Compare parameter variations
• Time-based rules - Holiday vs normal periods

Defining Profile Schema

Use Zod to define what a profile contains:

const profileSchema = z.object({
  highThreshold: z.number(),
  mediumThreshold: z.number(),
  blockedMerchants: z.array(z.string()),
  maxDailyTransactions: z.number(),
});

Using Inline Profiles

Pass the profile directly:

const result = engine.run(
  decision,
  input,
  { profile: { highThreshold: 10000, mediumThreshold: 5000 } }
);

Using Profile Registry

Create a registry to manage profiles by ID:

import { createProfileRegistry } from "@criterionx/core";

// Create a typed registry
const registry = createProfileRegistry<typeof usProfile>();

// Register profiles by ID
registry.register("us", usProfile);
registry.register("eu", euProfile);
registry.register("latam", latamProfile);

// Use by ID - pass registry as 4th argument
const result = engine.run(
  decision,
  input,
  { profile: "us" },  // String ID instead of object
  registry            // Registry with registered profiles
);

Profile Resolution

The engine resolves profiles in this order:

1. If profile is an object → use it directly (inline profile)
2. If profile is a string → look up in the provided registry
3. If string but no registry provided → return INVALID_INPUT
4. If string but not found in registry → return INVALID_INPUT

Creating a Registry

import { createProfileRegistry } from "@criterionx/core";

const registry = createProfileRegistry<MyProfileType>();

registry.register("production", productionProfile);
registry.register("staging", stagingProfile);

if (registry.has("production")) {
  const profile = registry.get("production");
}

Profile Patterns

By Region

const profiles = {
  "us": { currency: "USD", maxAmount: 50000 },
  "eu": { currency: "EUR", maxAmount: 40000 },
  "uk": { currency: "GBP", maxAmount: 35000 },
};

By Customer Tier

const profiles = {
  "standard": { discountRate: 0, creditLimit: 1000 },
  "silver": { discountRate: 0.05, creditLimit: 5000 },
  "gold": { discountRate: 0.10, creditLimit: 10000 },
  "platinum": { discountRate: 0.15, creditLimit: 50000 },
};

By Environment

const profiles = {
  "development": { rateLimit: 1000, strictMode: false },
  "staging": { rateLimit: 100, strictMode: true },
  "production": { rateLimit: 10, strictMode: true },
};

Best Practices

1. Validate with Zod - Catch invalid profiles early
2. Use meaningful IDs - us-premium not profile1
3. Document profile values - What does each field mean?
4. Version profiles - Store in config files with version control
5. Prefer registry for shared profiles - Avoid duplicating objects

Profile Sources

Profiles can come from:

• Config files - JSON/YAML loaded at startup
• Database - Dynamic profiles per tenant
• Environment variables - Deployment-specific settings
• Feature flags - A/B testing systems

The engine doesn't care where profiles come from - it just needs a valid object matching the schema.