Variable Contract

Design systems teams face a fundamental infrastructure challenge: there's no standard for how design variables should be versioned, governed, and synchronized across tools. This creates:

• Tool lock-in: Figma Variables, Adobe, and code-based token systems use incompatible formats
• Broken design-code handoff: No standard way to track which variable version is deployed in production
• Version control gaps: Design tools lack Git-like versioning for variables
• Governance chaos: No defined approval workflows for token changes affecting multiple brands
• Sync failures: Manual processes to keep Figma, Style Dictionary, and codebases aligned

After building Aurora at GM and seeing these pain points firsthand, I realized the industry needed an open specification defining how variables should be structured, versioned, and validated across the entire design-to-code pipeline.

Variable Contract is an open specification that defines JSON structures, validation rules, versioning strategies, and adapters for design variable governance and cross-tool synchronization.

Contract Structure

Defines a standardized JSON contract format:

• Metadata: Contract version, schema version, source of truth, timestamps
• Variable definitions: DTCG-compliant token structures with type safety
• Modes/themes: Multi-brand or multi-theme variable sets
• Dependencies: Track relationships between variables (aliases, references)
• Change log: Git-style commit history for variable changes

Semantic Versioning

Applies SemVer to design variables:

• MAJOR: Breaking changes (variable renamed or removed)
• MINOR: Backward-compatible additions (new variables added)
• PATCH: Value updates without structural changes
• Enables teams to understand impact before deploying token updates

Validation Schema

JSON Schema for validating contracts:

• Validates contract structure before deployment
• Ensures DTCG compliance for token definitions
• Checks for breaking changes between versions
• Prevents accidental variable deletions or renames

Tool Adapters

Reference implementations for cross-tool sync:

• Figma Variables Adapter: Export Figma Variables to contract format
• Style Dictionary Adapter: Convert contracts to Style Dictionary tokens
• Git Adapter: Track contract changes in version control
• CI/CD Integration: Validate contracts in pull requests

Governance Model

Defines approval workflows:

• Required approvers for MAJOR vs MINOR vs PATCH changes
• Multi-brand approval gates (e.g., GM's 4-brand scenario)
• Rollback procedures when deployed tokens break production
• Audit trail for all variable changes

DTCG Compliance

Aligned with W3C Design Tokens Community Group:

• Uses DTCG 2025.10 token format as foundation
• Extends spec with versioning and governance metadata
• Maintains compatibility with existing DTCG tools
• Contributed feedback to W3C community discussions

Real-World Testing

Developed from hands-on experience:

• Patterns tested during Aurora (GM) implementation
• Governance model based on real 4-brand token workflows
• Validation rules informed by production token failures
• Adapter designs driven by Figma Variables → Style Dictionary pipelines

Documentation & Spec

Comprehensive specification docs:

• Contract schema definition with examples
• Versioning strategy guidelines
• Adapter implementation patterns
• Governance workflow templates
• Migration guides from existing token systems

Variable Contract addresses foundational infrastructure gaps in the design systems ecosystem:

• Solves tool lock-in by defining portable variable structures that work across Figma, Adobe, and code-based systems
• Enables Git-like versioning for design variables, bringing version control discipline to design tools
• Standardizes governance with approval workflows that scale to multi-brand design systems
• Prevents breaking changes through SemVer and validation, protecting production applications
• DTCG-compliant foundation ensures compatibility with W3C standards and tooling ecosystem
• Open specification drives community discussion and potential standardization

The specification is published on GitHub as a living document, with ongoing development informed by design systems practitioners and W3C community feedback. The goal is to establish an industry standard for design variable governance that design systems teams can adopt regardless of their tool stack.