LDS Specification | ValidKernel Documentation

Documentation

Sections

Overview
Structure
Policies
Compression

Overview

LDS (Logical Data Structure) is a canonical format for expressing governance policies and validation rules. The format prioritizes determinism, auditability, and semantic density.

"Compression is not about making files smaller. It is about making meaning denser."

Design Principles

Determinism	Same input produces same output. Always.
Auditability	Every decision is traceable to source rules.
Minimalism	No optional features. No extensions.
Immutability	Policies cannot be modified at runtime.

File Structure

LDS files use the .lds extension and follow a strict structure:

# LDS Document Header
# Document ID: VK-POLICY-001
# Authority: L0 Governance
# Version: 1.0.0

metadata {
  name        = "policy_name"
  version     = "1.0.0"
  author      = "governance@example.com"
  created_at  = "2026-01-17T00:00:00Z"
  checksum    = "sha256:abc123..."
}

policy "policy_name" {
  description = "Policy description"
  
  # Rules defined here
}

Policy Definition

Rules

Rules define validation conditions and actions:

rule "rule_name" {
  description = "Rule description"
  priority    = 100  # Higher priority evaluated first
  
  condition {
    # Boolean expression
    input.size < 1048576
    auth.level >= 2
    context.source in ["api", "internal"]
  }
  
  action = allow  # allow | deny | audit
  
  on_match {
    log     = true
    message = "Rule matched"
  }
  
  on_deny {
    log     = true
    message = "Access denied: insufficient authorization"
    code    = "AUTH_LEVEL_REQUIRED"
  }
}

Conditions

Supported condition operators:

Operator	Description	Example
`==`	Equality	`input.type == "request"`
`!=`	Inequality	`auth.user != "anonymous"`
`<`, `>`	Comparison	`input.size < 1048576`
`in`	Membership	`role in ["admin", "user"]`
`matches`	Regex match	`email matches ".*@corp.com"`
`contains`	Substring	`path contains "/api/"`

Variables

Built-in context variables:

Variable	Description
`input.*`	Request input data
`auth.*`	Authentication context
`context.*`	Request metadata
`time.now`	Current timestamp
`request.id`	Unique request identifier

Semantic Compression

LDS achieves high compression ratios through semantic encoding rather than byte-level compression. Meaning is preserved while storage is minimized.

Compression Metrics

Average Ratio	5,600:1
Parse Latency	<1ms
Determinism	100%
Benchmark Tests	42/42 passed

Full Specification

The complete LDS Format Specification is available at Succinct Authority.

View Full Specification →