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ConstraintType

Standard constraint types defined in the PD-REL vocabulary.

Constraints define conditions that must be met for a rule to apply. They enable sophisticated access control based on time, usage limits, token ownership, location, and more. Custom constraints can be defined using URIs for domain-specific requirements.

Per the PD-REL v1.0 specification, constraints follow the principle of "Parameterization over On-Chain Logic" - focusing on declarative, parameter-driven conditions rather than arbitrary computation.

Examples​

import { ConstraintType } from '@pd-institute/pd-rel-sdk';

// Time-based access
const timeConstraint = {
  type: ConstraintType.TIME_PERIOD,
  value: {
    start: Date.now() / 1000,
    end: Date.now() / 1000 + 86400 // 24 hours
  }
};

// Token gating
const nftConstraint = {
  type: ConstraintType.TOKEN_GATED,
  value: {
    chainId: 1,
    contractAddress: '0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D',
    minBalance: 1
  }
};

// Combining multiple constraints (AND logic)
const rule = {
  action: 'USE',
  effect: 'permit',
  constraints: [timeConstraint, nftConstraint] // Both must be satisfied
};

Definition​

const ConstraintType: object

Properties​

ConstraintType.TIME_PERIOD​

Defines a valid time window (Unix timestamps in seconds).

TIME_PERIOD enables temporal access control:

  • Temporary licenses or trials
  • Event-based access windows
  • Subscription periods
  • Embargo or release dates

Value structure: { start: integer, end: integer } Per specification: "Defines a valid time window (Unix timestamps in seconds)."

Type: 'TIME_PERIOD'

Value: 'TIME_PERIOD'

Examples​

// 30-day access window
{
  type: ConstraintType.TIME_PERIOD,
  value: {
    start: 1704067200, // Jan 1, 2024 00:00 UTC
    end: 1706745599    // Jan 31, 2024 23:59:59 UTC
  }
}

ConstraintType.USAGE_COUNT​

Defines a maximum number of times the action can be performed.

USAGE_COUNT enables quantity-based restrictions:

  • Limited downloads or views
  • Restricted API calls
  • Finite reproductions
  • Usage quotas

Value type: number (maximum count)

Type: 'USAGE_COUNT'

Value: 'USAGE_COUNT'

Examples​

// Allow 100 downloads
{
  type: ConstraintType.USAGE_COUNT,
  value: 100
}

ConstraintType.TOKEN_GATED​

Requires the assignee to hold a minimum balance of a specific token.

TOKEN_GATED enables blockchain-based access control:

  • NFT holder benefits
  • DAO membership requirements
  • Token-weighted permissions
  • Staking requirements

Value structure: { chainId: number, contractAddress: string, minBalance: number }

Type: 'TOKEN_GATED'

Value: 'TOKEN_GATED'

Examples​

// Require BAYC NFT ownership
{
  type: ConstraintType.TOKEN_GATED,
  value: {
    chainId: 1, // Ethereum mainnet
    contractAddress: '0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D',
    minBalance: 1
  }
}

// Require 1000 governance tokens
{
  type: ConstraintType.TOKEN_GATED,
  value: {
    chainId: 137, // Polygon
    contractAddress: '0xGovToken...',
    minBalance: 1000
  }
}

ConstraintType.SPATIAL​

Restricts the action to a location (physical or virtual).

SPATIAL enables location-based access control:

  • Geographic restrictions (countries, regions)
  • Virtual world boundaries
  • Domain-specific access
  • IP-based geofencing

Value type: string (location identifier) or complex object

Type: 'SPATIAL'

Value: 'SPATIAL'

Examples​

// Country restriction
{
  type: ConstraintType.SPATIAL,
  value: 'US' // ISO country code
}

// Virtual world location
{
  type: ConstraintType.SPATIAL,
  value: 'https://decentraland.org/parcels/23,42'
}

// Complex spatial constraint
{
  type: ConstraintType.SPATIAL,
  value: {
    type: 'polygon',
    coordinates: [[...]],
    world: 'sandbox'
  }
}

ConstraintType.PAYMENT_AMOUNT_LTE​

Buyer’s acceptable maximum payment amount. The policy's required amount must be less than or equal to this value for a match.

Value structure (recommended): { amount: string, currency: string }

Type: 'PAYMENT_AMOUNT_LTE'

Value: 'PAYMENT_AMOUNT_LTE'

ConstraintType.PAYMENT_AMOUNT_GTE​

Buyer’s acceptable minimum payment amount. The policy's required amount must be greater than or equal to this value for a match.

Value structure (recommended): { amount: string, currency: string }

Type: 'PAYMENT_AMOUNT_GTE'

Value: 'PAYMENT_AMOUNT_GTE'

See Also​

Since​

Version 1.0.0